Quarterly report pursuant to Section 13 or 15(d)

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

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FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value And Fair Value Of Financial Instruments Disclosure) (Details) (USD $)
Mar. 31, 2014
Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount $ 4,890,500,000 $ 4,814,800,000
Long-term debt:    
Long-term Debt 3,291,700,000 3,043,500,000
Total long-term debt, carrying value 3,194,800,000 3,022,600,000
Seven Hundred Million Four Point Eight Seven Five Two Thousand Twenty-one Senior Note [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 700,000,000 700,000,000
Long-term debt:    
Long-term Debt 699,500,000 [1] 699,400,000 [1]
Senior Notes - $1.3 Billion [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 1,300,000,000.0 1,300,000,000.0
Senior Notes - $400 Million [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 400,000,000 400,000,000
Long-term debt:    
Long-term Debt 398,500,000 [2] 398,400,000 [2]
Senior Notes - $500 Million [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 500,000,000.0 500,000,000.0
Long-term debt:    
Long-term Debt 496,700,000 [3] 496,500,000 [3]
Revolving Credit Facility [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 1,750,000,000 1,750,000,000
Long-term debt:    
Revolving loan, carrying value 175,000,000 [4] 0 [4]
Equipment Loans [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, Face Amount 164,800,000 164,800,000
Long-term debt:    
Long-term Debt 156,500,000 161,700,000
Interest Rate Swap [Member]
    
Long-term debt:    
Fair Value Adjustment to Interest Rate Hedge 0 (2,100,000)
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
    
Long-term debt:    
Total long-term debt, fair value 3,528,100,000 3,217,700,000
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Seven Hundred Million Four Point Eight Seven Five Two Thousand Twenty-one Senior Note [Member]
    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 743,000,000 718,200,000
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Senior Notes - $1.3 Billion [Member]
    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 1,504,800,000 1,404,900,000
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Senior Notes - $400 Million [Member]
    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 442,000,000 432,100,000
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Senior Notes - $500 Million [Member]
    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 528,000,000 523,800,000
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]
    
Long-term debt:    
Revolving loan, fair value 175,000,000 0
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Equipment Loans [Member]
    
Long-term debt:    
Debt Instrument, Fair Value Disclosure 135,300,000 140,800,000
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
    
Long-term debt:    
Fair Value Adjustment to Interest Rate Hedge 0 (2,100,000)
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
    
Long-term debt:    
Total long-term debt, carrying value 3,194,800,000 3,022,600,000
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Seven Hundred Million Four Point Eight Seven Five Two Thousand Twenty-one Senior Note [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 699,500,000 699,400,000
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 1,289,800,000 1,289,600,000
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Senior Notes - $400 Million [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 398,500,000 398,400,000
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Senior Notes - $500 Million [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Senior Notes, Noncurrent 496,700,000 496,500,000.0
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]
    
Long-term debt:    
Revolving loan, carrying value 175,000,000 0
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Equipment Loans [Member]
    
Long-term debt:    
Long-term Debt 135,300,000 140,800,000
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
    
Long-term debt:    
Fair Value Adjustment to Interest Rate Hedge $ 0 $ (2,100,000)
[1] As of March 31, 2014 and December 31, 2013, the $700 million 4.875 percent senior notes were recorded at a par value of $700 million less unamortized discounts of $0.5 million and $0.6 million, respectively, based on an imputed interest rate of 4.89 percent.
[2] As of March 31, 2014 and December 31, 2013, the $400 million 5.90 percent senior notes were recorded at a par value of $400 million less unamortized discounts of $1.5 million and $1.6 million, respectively, based on an imputed interest rate of 5.98 percent.
[3] As of March 31, 2014 and December 31, 2013, the $500 million 3.95 percent senior notes were recorded at a par value of $500 million less unamortized discounts of $3.3 million and $3.5 million, respectively, based on an imputed interest rate of 4.14 percent.
[4] As of March 31, 2014, $175.0 million of revolving loans were drawn under the credit facility. As of December 31, 2013, no revolving loans were drawn under the credit facility. As of March 31, 2014 and December 31, 2013, the principal amount of letter of credit obligations totaled $5.2 million and $8.4 million, respectively, thereby reducing available borrowing capacity to $1.6 billion and $1.7 billion for each period, respectively.