FAIR VALUE MEASUREMENTS (Carrying Value And Fair Value Of Financial Instruments Disclosure) (Details) - USD ($)	Jun. 30, 2016		Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	$ 3,131,700,000		$ 3,448,200,000
$700 Million 4.875% 2021 Senior Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	336,200,000	[1],[2],[3],[4],[5],[6],[7],[8],[9]	412,500,000
$400 Million 5.90% 2020 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	225,600,000		290,800,000
$500 Million 3.95% 2018 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	283,600,000		311,200,000
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, Original Face Value	540,000,000		540,000,000
Two hundred Eighteen Point Five Million Eight Point Zero Twenty Twenty One Point Five Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	218,500,000
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, Original Face Value	430,100,000		544,200,000
Interest Rate Swap [Member]
Long-term debt:
Fair Value Adjustment to Interest Rate Hedge	2,100,000		2,300,000
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member]
Long-term debt:
Total long-term debt, fair value	2,507,200,000		2,699,400,000
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Long-term debt:
Fair Value Adjustment to Interest Rate Hedge	2,100,000		2,300,000
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member]
Long-term debt:
Total long-term debt, fair value	2,108,100,000		898,200,000
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Long-term debt:
Fair Value Adjustment to Interest Rate Hedge	2,100,000		2,300,000
Senior Notes [Member] | $700 Million 4.875% 2021 Senior Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	700,000,000		700,000,000
Senior Notes [Member] | Senior Notes One Point Three Billion [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	1,300,000,000		1,300,000,000
Senior Notes [Member] | $400 Million 5.90% 2020 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	400,000,000		400,000,000
Senior Notes [Member] | $500 Million 3.95% 2018 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Original Face Value	500,000,000		500,000,000
Senior Notes [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]
Debt Instrument, Original Face Value	540,000,000
Senior Notes [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]
Debt Instrument, Original Face Value	544,200,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $700 Million 4.875% 2021 Senior Note [Member]
Long-term debt:
Total long-term debt, fair value	334,700,000		410,600,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | Senior Notes One Point Three Billion [Member]
Long-term debt:
Total long-term debt, fair value	540,700,000		787,900,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 5.90% 2020 Senior Notes [Member]
Long-term debt:
Total long-term debt, fair value	224,300,000		288,900,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $500 Million 3.95% 2018 Senior Notes [Member]
Long-term debt:
Total long-term debt, fair value	282,200,000		309,100,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | Five hundred forty million Eight point two five Twenty twenty First Lien Notes [Member]
Long-term debt:
Total long-term debt, fair value	501,800,000		497,400,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | Five hundred Forty-four Million Seven Point Seven Five Twenty Twenty Second Lien Notes [Member]
Long-term debt:
Total long-term debt, fair value	328,600,000		403,200,000
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | Revolving Credit Facility [Member]
Long-term debt:
Total long-term debt, fair value			0
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Two hundred Eighteen Point Five Million Eight Point Zero Twenty Twenty One Point Five Lien Notes [Member]
Long-term debt:
Total long-term debt, fair value	292,800,000		0
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $700 Million 4.875% 2021 Senior Note [Member]
Long-term debt:
Total long-term debt, fair value	223,600,000		69,400,000
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | Senior Notes One Point Three Billion [Member]
Long-term debt:
Total long-term debt, fair value	349,600,000		137,400,000
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 5.90% 2020 Senior Notes [Member]
Long-term debt:
Total long-term debt, fair value	167,000,000		52,800,000
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $500 Million 3.95% 2018 Senior Notes [Member]
Long-term debt:
Total long-term debt, fair value	268,000,000		87,100,000
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | Five hundred forty million Eight point two five Twenty twenty First Lien Notes [Member]
Long-term debt:
Total long-term debt, fair value	548,100,000		414,500,000
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | Five hundred Forty-four Million Seven Point Seven Five Twenty Twenty Second Lien Notes [Member]
Long-term debt:
Total long-term debt, fair value	352,700,000		134,700,000
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Two hundred Eighteen Point Five Million Eight Point Zero Twenty Twenty One Point Five Lien Notes [Member]
Long-term debt:
Total long-term debt, fair value	197,000,000		0
Line of Credit [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]
Long-term debt:
Total long-term debt, fair value	0		0
Line of Credit [Member] | Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]
Long-term debt:
Total long-term debt, fair value	$ 0		$ 0

[1] As of December 31, 2015, no loans were drawn under the ABL Facility and we had total availability of $366.0 million as a result of borrowing base limitations. As of December 31, 2015, the principal amount of letter of credit obligations totaled $186.3 million and commodity hedge obligations totaled $0.5 million, thereby further reducing available borrowing capacity on our ABL Facility to $179.2 million.

[2] As of June 30, 2016, no loans were drawn under the ABL Facility and we had total availability of $425.6 million as a result of borrowing base limitations. As of June 30, 2016, the principal amount of letter of credit obligations totaled $112.8 million, thereby further reducing available borrowing capacity on our ABL Facility to $312.8 million.

[3] On March 2, 2016, we exchanged as part of an exchange offer $114.1 million of the 7.75 percent senior notes for $57.0 million of the 8.00 percent 1.5 lien notes that are recorded at a carrying value of $76.3 million, including undiscounted interest payments as of June 30, 2016.

[4] On March 2, 2016, we exchanged as part of an exchange offer $17.6 million of the 3.95 percent senior notes for $11.4 million of the 8.00 percent 1.5 lien notes that are recorded at a carrying value of $15.3 million, including undiscounted interest payments as of June 30, 2016. Additionally, during the first quarter of 2016 we entered into a debt for equity exchange; see NOTE 15 - CAPITAL STOCK for further discussion of this transaction.

[5] On March 2, 2016, we exchanged as part of an exchange offer $194.4 million of the 6.25 percent senior notes for $75.8 million of the 8.00 percent 1.5 lien notes that are recorded at a carrying value of $101.5 million, including undiscounted interest payments as of June 30, 2016.

[6] On March 2, 2016, we exchanged as part of an exchange offer $44.7 million of the 4.80 percent senior notes for $17.9 million of the 8.00 percent 1.5 lien notes that are recorded at a carrying value of $23.9 million, including undiscounted interest payments as of June 30, 2016. Additionally, during the second quarter of 2016 we entered into a debt for equity exchange; see NOTE 15 - CAPITAL STOCK for further discussion of this transaction.

[7] On March 2, 2016, we exchanged as part of an exchange offer $65.1 million of the 5.90 percent senior notes for $26.0 million of the 8.00 percent 1.5 lien notes that are recorded at a carrying value of $34.9 million, including undiscounted interest payments as of June 30, 2016.

[8] See the section entitled "$218.5 million 8.00 percent 2020 Senior Secured 1.5 Lien Notes - 2016 Exchange Offers" below for further discussion related to this instrument.

[9] n March 2, 2016, we exchanged as part of an exchange offer $76.3 million of the 4.875 percent senior notes for $30.5 million of the 8.00 percent 1.5 lien notes that are recorded at a carrying value of $40.9 million, including undiscounted interest payments