Long-Term Debt (Tables)

9 Months Ended

Sep. 30, 2016

Debt Disclosure [Abstract]

Schedule of Borrowing Base Utilization, Credit Facility [Table Text Block]

The borrowing base utilization grid under the Credit Agreement is as follows:

Borrowing Base Utilization Grid

Borrowing Base Utilization Percentage	<25%		≥25% <50%		≥50% <75%		≥75% <90%		≥90%
Eurodollar Loans	1.750	%	2.000	%	2.250	%	2.500	%	2.750	%
ABR Loans or Swingline Loans	0.750	%	1.000	%	1.250	%	1.500	%	1.750	%
Commitment Fee Rate	0.300	%	0.300	%	0.350	%	0.375	%	0.375	%

Schedule of Line of Credit Facilities [Table Text Block]

The following table presents the outstanding balance, total amount of letters of credit outstanding, and available borrowing capacity under the credit facility as of October 26, 2016, September 30, 2016, and December 31, 2015:

	As of October 26, 2016		As of September 30, 2016		As of December 31, 2015
	(in thousands)
Credit facility balance (1)	$	—	$	—	$	202,000
Letters of credit (2)	200		200		200
Available borrowing capacity	1,249,800		1,106,675		1,297,800
Total aggregate lender commitment amount	$	1,250,000	$	1,106,875	$	1,500,000

____________________________________________

⁽¹⁾ Unamortized deferred financing costs attributable to the credit facility are presented as a component of other noncurrent assets on the accompanying balance sheets and thus are not deducted from the credit facility balance.

⁽²⁾ Letters of credit outstanding reduce the amount available under the credit facility on a dollar-for-dollar basis.

Schedule of Long-term Debt Instruments [Table Text Block]

The Senior Notes, net of unamortized deferred financing costs line on the accompanying balance sheets as of September 30, 2016, and December 31, 2015, consisted of the following:

	As of September 30, 2016						As of December 31, 2015
	Senior Notes		Unamortized Deferred Financing Costs		Senior Notes, Net of Unamortized Deferred Financing Costs		Senior Notes		Unamortized Deferred Financing Costs		Senior Notes, Net of Unamortized Deferred Financing Costs
	(in thousands)
6.50% Senior Notes due 2021	$	346,955	$	3,547	$	343,408	$	350,000	$	4,106	$	345,894
6.125% Senior Notes due 2022	561,796		7,274		554,522		600,000		8,714		591,286
6.50% Senior Notes due 2023	394,985		4,618		390,367		400,000		5,231		394,769
5.0% Senior Notes due 2024	500,000		6,763		493,237		500,000		7,455		492,545
5.625% Senior Notes due 2025	500,000		7,845		492,155		500,000		8,524		491,476
6.75% Senior Notes due 2026	500,000		8,291		491,709		—		—		—
Total	$	2,803,736	$	38,338	$	2,765,398	$	2,350,000	$	34,030	$	2,315,970

Convertible Debt [Table Text Block]

The net carrying amount of the liability component of the Senior Convertible Notes, as reflected on the accompanying balance sheets, consisted of the following as of September 30, 2016:

	As of September 30, 2016
	(in thousands)
Principal amount of Senior Convertible Notes	$	172,500
Original debt discount due to allocation of proceeds to equity	(40,217		)
Accumulated amortization of debt discount	953
Unamortized deferred financing costs	(4,311		)
Net carrying amount	$	128,925