Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 28,106		$ (10,759)
Adjustments to net income to reconcile to net cash provided by operating activities:
Unrealized (gain) loss on derivatives, net	(24,079)		9,094
Depreciation, depletion and amortization	74,262		65,031
Impairment of natural gas and crude oil properties	1,023		952
Exploratory dry hole costs	401		171
Loss (gain) from sale of properties and equipment	(22,331)		(3,854)
Deferred income taxes	12,330		(10,543)
Stock-based compensation	3,901		5,549
Amortization of debt discount and issuance costs	3,547		3,400
Other	1,546		1,152
Changes in assets and liabilities	(9,011)		11,401
Net cash from operating activities	69,695		71,594
Cash flows from investing activities:
Capital expenditures	(165,157)		(151,355)
Acquisition of natural gas and crude oil properties	(309,285)		0
Proceeds from acquisition adjustments	11,969		0
Proceeds from sale of properties and equipment	187,340		10,062
Other	17,497		(1,542)
Net cash from investing activities	(292,630)		(139,751)
Cash flows from financing activities:
Proceeds from credit facility	483,250		65,927
Payment of credit facility	(425,250)		(49,526)
Proceeds from sale of equity, net of issuance costs	164,050		0
Contribution by investing partner in PDCM	0		6,407
Other	(1,397)		(2,252)
Net cash from financing activities	220,653		20,556
Net decrease in cash and cash equivalents	(2,282)		(47,601)
Cash and cash equivalents, beginning of period	8,238	[1]	54,372
Cash and cash equivalents, end of period	5,956		6,771
Cash payments (receipts) for:
Interest, net of capitalized interest	17,918		14,328
Income taxes, net of refunds	1,468		148
Non-cash investing activities:
Change in accounts payable related to purchases of properties and equipment	(12,927)		48,572
Change in asset retirement obligation, with a corresponding change tonatural gas and crude oil properties, net of disposals	$ 11,934		$ 304

[1] Derived from audited 2011 balance sheet.