Condensed Consolidated Statement of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income	$ 110,798	$ 92,791
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	140,783	47,771
Impairment of oil and gas properties	2,607	3,313
Deferred income taxes	66,648	55,015
Derivative instruments	(33,568)	(67,105)
Stock-based compensation expenses	6,627	2,592
Debt discount amortization and other	2,038	1,041
Working capital and other changes:
Change in accounts receivable	(69,163)	(41,286)
Change in inventory	(26,790)	(1,850)
Change in prepaid expenses	(2,009)	(297)
Change in other current assets	413	(337)
Change in other assets	(119)	(103)
Change in accounts payable and accrued liabilities	79,079	47,820
Change in other current liabilities	4,784
Change in other liabilities		317
Net cash provided by (used in) operating activities	282,128	139,682
Cash flows from investing activities:
Capital expenditures	(777,426)	(386,927)
Derivative settlements	2,784	(4,831)
Purchases of short-term investments	(126,213)	(164,913)
Redemptions of short-term investments	19,994	39,974
Advances to joint interest partners	(90)	(408)
Advances from joint interest partners	17,508	8,093
Net cash used in investing activities	(863,443)	(509,012)
Cash flows from financing activities:
Proceeds from issuance of senior notes	400,000	400,000
Purchases of treasury stock	(1,299)	(562)
Debt issuance costs	(7,955)	(10,027)
Net cash provided by (used in) financing activities	390,746	389,411
Increase (decrease) in cash and cash equivalents	(190,569)	20,081
Cash and cash equivalents:
Cash and cash equivalents at beginning of period	470,872	143,520
Cash and cash equivalents at end of period	280,303	163,601
Supplemental non-cash transactions:
Change in accrued capital expenditures	71,572	23,422
Change in asset retirement obligations	$ 7,774	$ 3,925

The total of the component of interest expense representing the noncash expenses charged against earnings in the period to amortize the long-term deferred financing costs and other income (expense) included in net income that results in no cash inflows or outflows in the period. Includes noncash adjustments to reconcile net income (loss) to cash provided by (used in) operating activities that are not separately disclosed.

No definition available.