Derivative instruments (Tables)

6 Months Ended

Jun. 30, 2011

Derivative instruments [Abstract]

Schedule of Derivative Instruments by Balance Sheet Location and Fair Value Table

The location and fair value of all of the Company's derivative instruments in the Consolidated Balance Sheets were as follows:

Asset Derivatives	Location on Consolidated Balance Sheets	Fair Value at June 30, 2011		Fair Value at June 30, 2010		Fair Value at December 31, 2010
		(In thousands)
Designated as hedges	Commodity derivative instruments	$	14,040	$	24,932	$	15,123
	Other assets - noncurrent		6,265		8,524		4,104
			20,305		33,456		19,227
Not designated as hedges	Commodity derivative instruments		194		-		-
	Other assets - noncurrent		-		-		-
			194		-		-
Total asset derivatives		$	20,499	$	33,456	$	19,227

Liability Derivatives	Location on Consolidated Balance Sheets	Fair Value at June 30, 2011		Fair Value at June 30, 2010		Fair Value at December 31, 2010
		(In thousands)
Designated as hedges	Commodity derivative instruments	$	17,780	$	1,961	$	15,069
	Other liabilities - noncurrent		6,735		-		6,483
			24,515		1,961		21,552
Not designated as hedges	Commodity derivative instruments		906		18,199		9,359
	Other liabilities - noncurrent		-		698		-
			906		18,897		9,359
Total liability derivatives		$	25,421	$	20,858	$	30,911