Long-Term Debt (Tables)

9 Months Ended

Sep. 30, 2017

Debt Disclosure [Abstract]

Schedule of Credit Agreement 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 Agreement as of October 26, 2017, September 30, 2017, and December 31, 2016:

	As of October 26, 2017		As of September 30, 2017		As of December 31, 2016
	(in thousands)
Credit facility balance (1)	$	—	$	—	$	—
Letters of credit (2)	200		200		200
Available borrowing capacity	924,800		924,800		1,164,800
Total aggregate lender commitment amount	$	925,000	$	925,000	$	1,165,000

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⁽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 totaled $3.5 million and $5.9 million as of September 30, 2017, and December 31, 2016, respectively.

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

Schedule of Senior Notes [Table Text Block]

The Senior Notes, net of unamortized deferred financing costs line on the accompanying balance sheets as of September 30, 2017, and December 31, 2016, consisted of the following:

	As of September 30, 2017						As of December 31, 2016
	Principal Amount		Unamortized Deferred Financing Costs		Senior Notes, Net of Unamortized Deferred Financing Costs		Principal Amount		Unamortized Deferred Financing Costs		Senior Notes, Net of Unamortized Deferred Financing Costs
	(in thousands)
6.50% Senior Notes due 2021 (1) (2)	$	344,611	$	2,830	$	341,781	$	346,955	$	3,372	$	343,583
6.125% Senior Notes due 2022 (2)	561,796		6,095		555,701		561,796		6,979		554,817
6.50% Senior Notes due 2023 (2)	394,985		3,889		391,096		394,985		4,436		390,549
5.0% Senior Notes due 2024	500,000		5,841		494,159		500,000		6,533		493,467
5.625% Senior Notes due 2025	500,000		6,940		493,060		500,000		7,619		492,381
6.75% Senior Notes due 2026 (3)	500,000		7,451		492,549		500,000		8,078		491,922
Total	$	2,801,392	$	33,046	$	2,768,346	$	2,803,736	$	37,017	$	2,766,719

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⁽¹⁾  During the first quarter of 2017, the Company repurchased a total of $2.3 million in aggregate principal amount of 6.50% Senior Notes due 2021 in open market transactions at a slight premium. The Company canceled all of these repurchased Senior Notes upon cash settlement.

⁽²⁾  During the first quarter of 2016, the Company repurchased a total of $46.3 million in aggregate principal amount of certain of its Senior Notes in open market transactions for a settlement amount of $29.9 million, excluding interest. The Company recorded a net gain on extinguishment of debt of approximately $15.7 million for the nine months ended September 30, 2016. This amount includes a gain of approximately $16.4 million associated with the discount realized upon repurchase, which was partially offset by approximately $0.7 million related to the acceleration of unamortized deferred financing costs. The Company canceled all of these repurchased Senior Notes upon cash settlement.

⁽³⁾  On September 12, 2016, the Company issued 6.75% Senior Notes due September 15, 2026. The Company received net proceeds of $491.6 million after deducting paid and accrued fees. The net proceeds were used to partially fund the Rock Oil Acquisition that closed on October 4, 2016.

Schedule of Senior Convertible Notes [Table Text Block]

The net carrying amount of the liability component of the Senior Convertible Notes, as reflected on the accompanying balance sheets as of September 30, 2017, and December 31, 2016, consisted of the following:

	As of September 30, 2017			As of December 31, 2016
	(in thousands)
Principal amount of Senior Convertible Notes	$	172,500		$	172,500
Unamortized debt discount	(32,048		)	(37,513		)
Unamortized deferred financing costs	(3,440		)	(4,131		)
Net carrying amount	$	137,012		$	130,856