Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value And Fair Value Of Financial Instruments Disclosure) (Details)

v2.4.1.9
FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value And Fair Value Of Financial Instruments Disclosure) (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount $ 3,621,500,000us-gaap_DebtInstrumentFaceAmount $ 3,980,000,000us-gaap_DebtInstrumentFaceAmount
Long-term debt:    
Long-term Debt 2,880,900,000us-gaap_LongTermDebt 2,843,300,000us-gaap_LongTermDebt
Total long-term debt, carrying value 2,880,900,000us-gaap_LongTermDebtNoncurrent 2,843,300,000us-gaap_LongTermDebtNoncurrent
$700 Million 4.875% 2021 Senior Note [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 700,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
700,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
Long-term debt:    
Long-term Debt 422,900,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
[1] 689,500,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
[1]
Senior Notes - $1.3 Billion [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 1,300,000,000.0us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_SeniorNotesOnePointThreeBillionMember
1,300,000,000.0us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_SeniorNotesOnePointThreeBillionMember
$400 Million 5.90% 2020 Senior Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 400,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
400,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
Long-term debt:    
Long-term Debt 325,700,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
[2] 393,700,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
[2]
$500 Million 3.95% 2018 Senior Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 500,000,000.0us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
500,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
Long-term debt:    
Long-term Debt 433,800,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
[3] 477,400,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
[3]
Five hundred forty million Eight point two five Twenty twenty First Lien Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 540,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
0us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
Long-term debt:    
Long-term Debt 503,500,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
[3]  
Five hundred Forty-four Million Seven Point Seven Five Twenty Twenty Second Lien Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 544,200,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
0us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
Long-term debt:    
Debt Instrument, Fair Value Disclosure 397,200,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
 
Long-term Debt 397,200,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
[3]  
Revolving Credit Facility [Member]    
Long-term debt:    
Revolving loan, carrying value 0us-gaap_LineOfCredit
/ us-gaap_DebtInstrumentAxis
= us-gaap_RevolvingCreditFacilityMember
[4] 0us-gaap_LineOfCredit
/ us-gaap_DebtInstrumentAxis
= us-gaap_RevolvingCreditFacilityMember
[5]
Interest Rate Swap [Member]    
Long-term debt:    
Fair Value Adjustment to Interest Rate Hedge 2,700,000clf_FairValueAdjustmenttoInterestRateHedge
/ us-gaap_DebtInstrumentAxis
= us-gaap_InterestRateSwapMember
2,800,000clf_FairValueAdjustmenttoInterestRateHedge
/ us-gaap_DebtInstrumentAxis
= us-gaap_InterestRateSwapMember
Fair Value, Inputs, Level 2 [Member]    
Long-term debt:    
Total long-term debt, fair value 2,081,700,000us-gaap_LongTermDebtFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
1,614,200,000us-gaap_LongTermDebtFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | $700 Million 4.875% 2021 Senior Note [Member]    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 220,000,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
367,300,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Senior Notes - $1.3 Billion [Member]    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 425,800,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_SeniorNotesOnePointThreeBillionMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
704,000,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_SeniorNotesOnePointThreeBillionMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | $400 Million 5.90% 2020 Senior Notes [Member]    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 190,500,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
228,100,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | $500 Million 3.95% 2018 Senior Notes [Member]    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 337,900,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
312,000,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Five hundred forty million Eight point two five Twenty twenty First Lien Notes [Member]    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 507,600,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Five hundred Forty-four Million Seven Point Seven Five Twenty Twenty Second Lien Notes [Member]    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 397,200,000us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_DebtInstrumentFairValue
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]    
Long-term debt:    
Revolving loan, fair value 0us-gaap_LinesOfCreditFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_LinesOfCreditFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]    
Long-term debt:    
Fair Value Adjustment to Interest Rate Hedge 2,700,000clf_FairValueAdjustmenttoInterestRateHedge
/ us-gaap_DebtInstrumentAxis
= us-gaap_InterestRateSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
2,800,000clf_FairValueAdjustmenttoInterestRateHedge
/ us-gaap_DebtInstrumentAxis
= us-gaap_InterestRateSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]    
Long-term debt:    
Total long-term debt, carrying value 2,880,900,000us-gaap_LongTermDebtNoncurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
2,843,300,000us-gaap_LongTermDebtNoncurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | $700 Million 4.875% 2021 Senior Note [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 422,900,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
689,500,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_SevenHundredMillionFourPointEightSevenFiveTwoThousandTwentyoneSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Senior Notes - $1.3 Billion [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 795,100,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_SeniorNotesOnePointThreeBillionMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
1,279,900,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_SeniorNotesOnePointThreeBillionMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | $400 Million 5.90% 2020 Senior Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 325,700,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
393,700,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FourHundredMillionFivePointNineZeroTwoThousandAndTwentySeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | $500 Million 3.95% 2018 Senior Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 433,800,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
477,400,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FiveHundredMillionThreePointNineFiveTwoThousandEighteenSeniorNoteMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Five hundred forty million Eight point two five Twenty twenty First Lien Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 503,500,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
0us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredfortymillionEightpointtwofiveTwentytwentyFirstLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Five hundred Forty-four Million Seven Point Seven Five Twenty Twenty Second Lien Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 397,200,000us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
0us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= clf_FivehundredFortyfourMillionSevenPointSevenFiveTwentyTwentySecondLienNotesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 0us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
0us-gaap_SeniorLongTermNotes
/ us-gaap_DebtInstrumentAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]    
Long-term debt:    
Fair Value Adjustment to Interest Rate Hedge $ 2,700,000clf_FairValueAdjustmenttoInterestRateHedge
/ us-gaap_DebtInstrumentAxis
= us-gaap_InterestRateSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
$ 2,800,000clf_FairValueAdjustmenttoInterestRateHedge
/ us-gaap_DebtInstrumentAxis
= us-gaap_InterestRateSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
[1] During the first quarter of 2015, we purchased $58.3 million of outstanding 4.875 percent senior notes that were trading at a discount of 52.0 percent which resulted in a gain on extinguishment of $20.0 million. In addition, on March 27, 2015, we exchanged as part of a tender offer $208.5 million of the 4.875 percent senior notes for $170.3 million of the 7.75 percent second lien notes at a discount of $46.0 million based on an imputed interest rate of 15.55 percent, resulting in a gain on extinguishment of $83.1 million, net of amounts expensed for unamortized original issue discount and deferred origination fees. As of March 31, 2015, the $700.0 million 4.875 percent senior notes were recorded at a par value of $423.2 million less unamortized discounts of $0.3 million, based on an imputed interest rate of 4.89 percent. As of December 31, 2014, the $700.0 million 4.875 percent senior notes were recorded at a par value of $690.0 million less unamortized discounts of $0.5 million based on an imputed interest rate of 4.88 percent.
[2] During the first quarter of 2015, we purchased $1.3 million of outstanding 5.90 percent senior notes that were trading at a discount of 58.0 percent, which resulted in a gain on extinguishment of $0.3 million. In addition, on March 27, 2015, we exchanged as part of a tender offer $67.0 million of the 5.90 percent senior notes for $57.5 million of the 7.75 percent second lien notes at a discount of $15.5 million based on an imputed interest rate of 15.55 percent, resulting in a gain on extinguishment of $24.5 million, net of amounts expensed for unamortized original issue discount and deferred origination fees. As of March 31, 2015, the $400.0 million 5.90 percent senior notes were recorded at a par value of $326.8 million less unamortized discounts of $1.1 million, based on an imputed interest rate of 5.98 percent. As of December 31, 2014, the $400.0 million 5.90 percent senior notes were recorded at a par value of $395.0 million less unamortized discounts of $1.3 million based on an imputed interest rate of 5.98 percent.
[3] During the first quarter of 2015, we purchased $44.0 million of outstanding 3.95 percent senior notes that were trading at a discount of 77.5 percent, which resulted in a gain on the extinguishment of debt of $7.1 million. As of March 31, 2015, the $500.0 million 3.95 percent senior notes were recorded at a par value of $436.0 million less unamortized discounts of $2.2 million, based on an imputed interest rate of 6.32 percent. As of December 31, 2014, the $500.0 million 3.95 percent senior notes were recorded at a par value of $480.0 million less unamortized discounts of $2.6 million based on an imputed interest rate of 5.17 percent.
[4] As of March 31, 2015, no loans were drawn under the ABL Facility and we had total availability of $441.1 million as a result of borrowing base limitations. As of March 31, 2015, the principal amount of letter of credit obligations totaled $136.2 million and foreign exchange hedge obligations totaled $5.5 million, thereby further reducing available borrowing capacity on our ABL Facility to $299.4 million.
[5] As of December 31, 2014, we had no revolving loans drawn under the revolving credit agreement of which had $1.125 billion availability. As of December 31, 2014, the principal amount of letter of credit obligations totaled $149.5 million, thereby further reducing available borrowing capacity on the revolving credit agreement to $975.5 million.