Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2018

Valuation of Financial Instruments by Pricing Levels

The following tables summarize the valuation of financial instruments by pricing levels that were accounted for at fair value on a recurring basis as of June 30, 2018 and December 31, 2017.



	Fair value measurements at June 30, 2018 using:
In thousands	Level 1		Level 2			Level 3		Total
Derivative liabilities:
Swaps	$	—	$	(8,862	)	$	—	$	(8,862	)
Total	$	—	$	(8,862	)	$	—	$	(8,862	)

	Fair value measurements at December 31, 2017 using:
In thousands	Level 1		Level 2			Level 3		Total
Derivative assets:
Swaps	$	—	$	2,603		$	—	$	2,603
Total	$	—	$	2,603		$	—	$	2,603

Quantitative Information about Significant Unobservable Inputs

The following table sets forth quantitative information about the significant unobservable inputs used by the Company to calculate the fair value of proved crude oil and natural gas properties using a discounted cash flow method.



Unobservable Input		Assumption
Future production		Future production estimates for each property
Forward commodity prices		Forward NYMEX strip prices through 2022 (adjusted for differentials), escalating 3% per year thereafter
Operating costs		Estimated costs for the current year, escalating 3% per year thereafter
Productive life of field		Ranging from 1 to 38 years
Discount rate		10%

Property Impairments

The following table sets forth the non-cash impairments of both proved and unproved properties for the indicated periods. Proved and unproved property impairments are recorded under the caption “Property impairments” in the unaudited condensed consolidated statements of comprehensive income (loss).



	Three months ended June 30,				Six months ended June 30,
In thousands	2018		2017		2018		2017
Proved property impairments	$	—	$	81,469	$	—	$	82,340
Unproved property impairments	29,162		41,847		62,946		92,349
Total	$	29,162	$	123,316	$	62,946	$	174,689

Fair Values of Financial Instruments not Recorded at Fair Value

The following table sets forth the estimated fair values of financial instruments that are not recorded at fair value in the condensed consolidated financial statements.



	June 30, 2018				December 31, 2017
In thousands	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Debt:
Revolving credit facility	$	—	$	—	$	188,000	$	188,000
Note payable	8,845		8,800		9,974		9,900
5% Senior Notes due 2022 (1)	1,997,782		2,030,100		1,997,576		2,040,000
4.5% Senior Notes due 2023	1,487,803		1,522,900		1,486,690		1,526,800
3.8% Senior Notes due 2024	992,588		976,000		992,036		988,800
4.375% Senior Notes due 2028	988,090		994,100		988,061		987,200
4.9% Senior Notes due 2044	691,435		683,600		691,354		679,900
Total debt	$	6,166,543	$	6,215,500	$	6,353,691	$	6,420,600