Quarterly report pursuant to Section 13 or 15(d)

DEBT AND CREDIT FACILITIES (Narrative) (Details)

v3.7.0.1
DEBT AND CREDIT FACILITIES (Narrative) (Details)
 3 Months Ended 6 Months Ended
Jun. 30, 2017
USD ($)
Jun. 30, 2016
USD ($)
Jun. 30, 2017
USD ($)
Jun. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Line of Credit Facility [Line Items]          
Payments of Debt Issuance Costs     $ 8,500,000 $ 5,200,000  
Gain (loss) on extinguishment/restructuring of debt $ (4,900,000) $ 3,600,000 (76,800,000) $ 182,400,000  
Debt redemption premiums paid 2,900,000   47,600,000    
$500 Million 5.75% 2025 Senior Notes [Member]          
Line of Credit Facility [Line Items]          
Debt Instrument, Par Value $ 500,000,000   $ 500,000,000    
Debt Instrument, Interest Rate, Effective Percentage 5.75%   5.75%    
Note Redemption Price, Percent of Principal Amount to be Redeemed 100.00%   100.00%    
Amount in aggregate that can be redeemed on or prior to March 1, 2020     0.3500    
Repurchase price if triggering event occurs     1.01    
Redemption Price of 35 percent or less of Outstanding     1.0575    
In the Event of Default Amount that will Accelerate     0.25    
Unamortized Debt Issuance Expense $ 8,100,000   $ 8,100,000    
Revolving Credit Facility [Member]          
Line of Credit Facility [Line Items]          
Credit facility, amount outstanding 0   0   $ 0
Line of Credit Facility, Maximum Borrowing Capacity 296,600,000   296,600,000   333,000,000
Debt Instrument, Par Value 550,000,000   550,000,000   550,000,000
Letters of credit outstanding 82,500,000   82,500,000   106,000,000
Credit facility remaining capacity $ 214,100,000   $ 214,100,000   $ 227,000,000