Derivative instruments (Tables)

3 Months Ended

Mar. 31, 2015

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
	March 31,
	2015			2014
	(In thousands)
Commodity derivatives designated as cash flow hedges:
Amount of loss reclassified from accumulated other comprehensive loss into operating revenues (effective portion), net of tax	$	—		$	244
Interest rate derivatives designated as cash flow hedges:
Amount of loss reclassified from accumulated other comprehensive loss into interest expense (effective portion), net of tax	99			100
Commodity derivatives not designated as hedging instruments:
Amount of loss recognized in operating revenues, before tax	(11,208		)	(6,712		)

Derivative instruments

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 March 31, 2015		Fair Value at March 31, 2014		Fair Value at December 31, 2014
		(In thousands)
Not designated as hedges:
Commodity derivatives	Commodity derivative instruments	$	7,127	$	81	$	18,335
	Other assets - noncurrent	—		249		—
Total asset derivatives		$	7,127	$	330	$	18,335

Liability Derivatives	Location on Consolidated Balance Sheets	Fair Value at March 31, 2015		Fair Value at March 31, 2014		Fair Value at December 31, 2014
		(In thousands)
Not designated as hedges:
Commodity derivatives	Commodity derivative instruments	$	—	$	12,186	$	—
Total liability derivatives		$	—	$	12,186	$	—

Offsetting assets and liabilities master netting

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:

March 31, 2015	Gross Amounts Recognized on the Consolidated Balance Sheets		Gross Amounts Not Offset on the Consolidated Balance Sheets		Net
	(In thousands)
Assets:
Commodity derivatives	$	7,127	$	—	$	7,127
Total assets	$	7,127	$	—	$	7,127

March 31, 2014	Gross Amounts Recognized on the Consolidated Balance Sheets		Gross Amounts Not Offset on the Consolidated Balance Sheets			Net
	(In thousands)
Assets:
Commodity derivatives	$	330	$	(330	)	$	—
Total assets	$	330	$	(330	)	$	—
Liabilities:
Commodity derivatives	$	12,186	$	(330	)	$	11,856
Total liabilities	$	12,186	$	(330	)	$	11,856

December 31, 2014	Gross Amounts Recognized on the Consolidated Balance Sheets		Gross Amounts Not Offset on the Consolidated Balance Sheets		Net
	(In thousands)
Assets:
Commodity derivatives	$	18,335	$	—	$	18,335
Total assets	$	18,335	$	—	$	18,335