Additional Balance Sheet Detail (Tables)

12 Months Ended

Dec. 31, 2011

Components of Selected Balance Sheet Accounts

The following table summarizes components of selected balance sheet accounts as of the dates presented:

	As of December 31,
	2011		2010
Other current assets:
Tubular inventory and well materials	$	14,251	$	3,600
Prepaid expenses		699		633
	$	14,950	$	4,233
Other assets:
Debt issuance costs	$	16,993	$	14,300
Long-term investments - Rabbi Trust 1		3,088		6,440
Other		51		47
	$	20,132	$	20,787
Accounts payable and accrued liabilities:
Trade accounts payable	$	30,186	$	33,831
Drilling costs		30,948		31,770
Royalties		15,235		9,308
Production and franchise taxes		3,495		6,012
Compensation 2, 3		5,186		9,631
Interest		5,964		2,977
Other		3,490		6,132
	$	94,504	$	99,661
Other liabilities:
Asset retirement obligations	$	6,283	$	7,364
Defined benefit pension obligations 2		1,763		1,766
Postretirement health care benefit obligations 2		3,022		2,976
Deferred compensation 1		3,172		6,952
Other		1,647		900
	$	15,887	$	19,958