CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows From Operating Activities
Net income (loss)	$ (707,064)	$ 637,769	$ 603,833
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	814,710	707,966	591,943
Impairment of natural gas and oil properties	1,939,734
Deferred income taxes	(461,828)	409,023	379,720
Unrealized gain on derivatives	(272)	(281)	(4,289)
Stock-based compensation	11,795	10,550	9,820
Other	1,807	991	(1,348)
Change in assets and liabilities:
Accounts receivable	(35,717)	9,659	(88,488)
Inventories	18,111	(12,975)	5,099
Accounts payable	41,275	11,490	65,782
Taxes payable	22,289	(9,360)	24,551
Interest payable	5,058	610	179
Advances from partners	(15,163)	2,377	29,299
Tax benefit for stock-based compensation		(14,626)
Other assets and liabilities	19,207	(13,376)	26,484
Net cash provided by operating activities	1,653,942	1,739,817	1,642,585
Cash Flows From Investing Activities
Capital investments	(2,107,755)	(2,184,474)	(2,073,174)
Proceeds from sale of property and equipment	201,101	154,526	350,227
Transfers to restricted cash	(167,788)	(85,055)	(356,035)
Transfers from restricted cash	159,246	85,055	356,035
Other	8,519	5,158	(2,684)
Net cash used in investing activities	(1,906,677)	(2,024,790)	(1,725,631)
Cash Flows From Financing Activities
Payments on current portion of long-term debt	(1,200)	(1,200)	(1,200)
Payments on revolving long-term debt	(2,263,900)	(3,445,900)	(2,958,100)
Borrowings under revolving long-term debt	1,592,400	3,696,200	3,054,800
Change in bank drafts outstanding	(35,608)	24,637	(11,545)
Proceeds from issuance of long-term debt	998,780
Debt issuance costs	(8,339)
Revolving credit facility costs		(10,211)
Proceeds from exercise of common stock options	9,184	6,412	3,897
Tax benefit for stock-based compensation		14,626
Other	(428)	(261)	(1,612)
Net cash provided by financing activities	290,889	284,303	86,240
Effect of exchange rate changes on cash	(198)	242	(323)
Increase (decrease) in cash and cash equivalents	37,956	(428)	2,871
Cash and cash equivalents at beginning of year	15,627	16,055	13,184
Cash and cash equivalents at end of year	$ 53,583	$ 15,627	$ 16,055