Derivative Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2015

Derivative Instruments Not Designated as Hedging Instruments [Abstract]

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]

The following table presents the balance sheet location and fair value amounts of our derivative instruments on the condensed consolidated balance sheets:

			Fair Value
Derivative instruments:		Balance sheet line item	March 31, 2015		December 31, 2014
			(in thousands)
Derivative assets:	Current
	Commodity contracts
	Related to crude oil and natural gas sales	Fair value of derivatives	$	202,853	$	186,886
	Related to natural gas marketing	Fair value of derivatives	435		590
	Basis protection contracts
	Related to crude oil and natural gas sales	Fair value of derivatives	581		19
			203,869		187,495
	Non-current
	Commodity contracts
	Related to crude oil and natural gas sales	Fair value of derivatives	111,994		112,599
	Related to natural gas marketing	Fair value of derivatives	205		220
	Basis protection contracts
	Related to crude oil and natural gas sales	Fair value of derivatives	326		—
			112,525		112,819
Total derivative assets			$	316,394	$	300,314
Derivative liabilities:	Current
	Commodity contracts
	Related to natural gas marketing	Fair value of derivatives	$	404	$	545
	Basis protection contracts
	Related to crude oil and natural gas sales	Fair value of derivatives	—		25
			404		570
	Non-current
	Commodity contracts
	Related to crude oil and natural gas sales	Fair value of derivatives	25		—
	Related to natural gas marketing	Fair value of derivatives	187		197
			212		197
Total derivative liabilities			$	616	$	767

The following table presents the impact of our derivative instruments on our condensed consolidated statements of operations:

	Three Months Ended March 31,
Condensed consolidated statement of operations line item	2015			2014
	(in thousands)
Commodity price risk management gain (loss), net
Net settlements	$	50,412		$	(7,238	)
Net change in fair value of unsettled derivatives	16,250			(17,671		)
Total commodity price risk management gain (loss), net	$	66,662		$	(24,909	)
Sales from natural gas marketing
Net settlements	$	232		$	(476	)
Net change in fair value of unsettled derivatives	(170		)	(312		)
Total sales from natural gas marketing	$	62		$	(788	)
Cost of natural gas marketing
Net settlements	$	(218	)	$	535
Net change in fair value of unsettled derivatives	150			296
Total cost of natural gas marketing	$	(68	)	$	831

All of our financial derivative agreements contain master netting provisions that provide for the net settlement of all contracts through a single payment in the event of early termination. Our fixed-price physical purchase and sale agreements that qualify as derivative contracts are not subject to master netting provisions and are not significant. We have elected not to offset the fair value positions recorded on our condensed consolidated balance sheets.

The following table reflects the impact of netting agreements on gross derivative assets and liabilities:

As of March 31, 2015	Derivative instruments, recorded in condensed consolidated balance sheet, gross		Effect of master netting agreements			Derivative instruments, net
	(in thousands)
Asset derivatives:
Derivative instruments, at fair value	$	316,394	$	(26	)	$	316,368
Liability derivatives:
Derivative instruments, at fair value	$	616	$	(26	)	$	590

As of December 31, 2014	Derivative instruments, recorded in condensed consolidated balance sheet, gross		Effect of master netting agreements			Derivative instruments, net
	(in thousands)
Asset derivatives:
Derivative instruments, at fair value	$	300,314	$	(29	)	$	300,285
Liability derivatives:
Derivative instruments, at fair value	$	767	$	(29	)	$	738