Derivative instruments (Tables)

6 Months Ended

Jun. 30, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of derivative instruments, gain (losses)

The gains and losses on derivative instruments were as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2013			2012			2013			2012
	(In thousands)
Commodity derivatives designated as cash flow hedges:
Amount of gain (loss) recognized in accumulated other comprehensive loss (effective portion), net of tax	$	—		$	28,018		$	(6,154	)	$	23,863
Amount of (gain) loss reclassified from accumulated other comprehensive loss into operating revenues (effective portion), net of tax	(871		)	(1,840		)	(3,714		)	(4,687		)
Amount of gain (loss) recognized in operating revenues (ineffective portion), before tax	—			3,863			(1,422		)	(388		)
Interest rate derivatives designated as cash flow hedges:
Amount of gain (loss) recognized in accumulated other comprehensive loss (effective portion), net of tax	254			(2,245		)	560			(1,357		)
Amount of loss reclassified from accumulated other comprehensive loss into interest expense (effective portion), net of tax	475			6			546			21
Amount of loss recognized in interest expense (ineffective portion), before tax	(610		)	—			(769		)	—
Commodity derivatives not designated as hedging instruments:
Amount of gain recognized in operating revenues, before tax	13,047			993			8,637			1,048

Derivative instruments (Tables)

The location and fair value of the gross amount of the Company's derivative instruments on the Consolidated Balance Sheets were as follows:

Asset Derivatives	Location on Consolidated Balance Sheets	Fair Value at June 30, 2013		Fair Value at June 30, 2012		Fair Value at December 31, 2012
		(In thousands)
Designated as hedges:
Commodity derivatives	Commodity derivative instruments	$	—	$	36,360	$	18,084
	Other assets - noncurrent	—		11,445		—
		—		47,805		18,084
Not designated as hedges:
Commodity derivatives	Commodity derivative instruments	9,797		640		220
	Other assets - noncurrent	1,447		212		—
		11,244		852		220
Total asset derivatives		$	11,244	$	48,657	$	18,304

Liability Derivatives	Location on Consolidated Balance Sheets	Fair Value at June 30, 2013		Fair Value at June 30, 2012		Fair Value at December 31, 2012
		(In thousands)
Designated as hedges:
Commodity derivatives	Commodity derivative instruments	$	—	$	789	$	—
Interest rate derivatives	Other accrued liabilities	—		6,963		6,255
		—		7,752		6,255
Not designated as hedges:
Commodity derivatives	Commodity derivative instruments	1,388		248		—
		1,388		248		—
Total liability derivatives		$	1,388	$	8,000	$	6,255

All of the Company's commodity and interest rate derivative instruments at June 30, 2013 and 2012, and December 31, 2012, were subject to legally enforceable master netting agreements. However, the Company's policy is to not offset fair value amounts for derivative instruments and, as a result, the Company's derivative assets and liabilities are presented gross on the Consolidated Balance Sheets. The gross derivative assets and liabilities (excluding settlement receivables and payables that may be subject to the same master netting agreements) presented on the Consolidated Balance Sheets and the amount eligible for offset under the master netting agreements is presented in the following table:

June 30, 2013	Gross Amounts Recognized on the Consolidated Balance Sheets		Gross Amounts Not Offset on the Consolidated Balance Sheets			Net
	(In thousands)
Assets:
Commodity derivatives	$	11,244	$	(1,388	)	$	9,856
Total assets	$	11,244	$	(1,388	)	$	9,856
Liabilities:
Commodity derivatives	$	1,388	$	(1,388	)	$	—
Total liabilities	$	1,388	$	(1,388	)	$	—

June 30, 2012	Gross Amounts Recognized on the Consolidated Balance Sheets		Gross Amounts Not Offset on the Consolidated Balance Sheets			Net
	(In thousands)
Assets:
Commodity derivatives	$	48,657	$	(809	)	$	47,848
Total assets	$	48,657	$	(809	)	$	47,848
Liabilities:
Commodity derivatives	$	1,037	$	(809	)	$	228
Interest rate derivatives	6,963		—			6,963
Total liabilities	$	8,000	$	(809	)	$	7,191

December 31, 2012	Gross Amounts Recognized on the Consolidated Balance Sheets		Gross Amounts Not Offset on the Consolidated Balance Sheets		Net
	(In thousands)
Assets:
Commodity derivatives	$	18,304	$	—	$	18,304
Total assets	$	18,304	$	—	$	18,304
Liabilities:
Interest rate derivatives	$	6,255	$	—	$	6,255
Total liabilities	$	6,255	$	—	$	6,255