Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities
Net loss	$ (165,277)	$ (322,046)	$ (35,581)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities -
Depreciation, depletion and amortization	298,574	220,657	152,780
Impairment of oil and gas properties	57,639	63,267	45,799
Gain on exchange/disposal of properties	(27,000)	(26,720)	(12,433)
Accretion of asset retirement obligation	15,000	13,827	11,676
Deferred income tax expense (benefit)	19,395	(35,414)	(23,079)
Derivative (income) expense	(38,188)	20,090	39,648
(Gain) loss on debt extinguishment	(1,095)	18,973
Stock-based compensation	6,683	6,825	7,951
Amortization of deferred revenue		(19,336)	(39,893)
Noncash interest expense	35,320	28,078	13,262
Other noncash items, net	(694)	3,245	2,443
Changes in assets and liabilities -
Accounts receivable and other current assets	59,061	(31,979)	50,402
Accounts payable and accruals	(29,491)	23,213	(53,168)
Other assets and liabilities	(32,836)	40	20
Net cash provided by (used in) operating activities	197,091	(37,280)	159,827
Cash flows from investing activities
Additions to oil and gas properties	(436,910)	(598,108)	(635,447)
Proceeds from disposition of properties	27,000	17,053	13,000
Decrease (increase) in restricted cash	10,157	(29,766)	(10,504)
Net cash used in investing activities	(399,753)	(610,821)	(632,951)
Cash flows from financing activities
Proceeds from senior second lien notes		1,492,965
Proceeds from first lien term loans	59,400	147,000
Proceeds from term loan facility-ATP Titan assets	91,000	238,750
Proceeds from term loans		46,000	19,000
Payments of term loans	(25,375)	(1,263,727)	(176,512)
Deferred financing costs	(4,561)	(62,937)	(6,490)
Proceeds from common stock issuances, net of costs			170,629
Proceeds from preferred stock issuances, net of costs	149,866		135,549
Purchase of capped-call options on ATP common stock	(26,500)
Proceeds from other long-term obligations	85,326	231,888	89,011
Payments of other long-term obligations	(180,848)	(102,818)	(2,298)
Sale of redeemable noncontrolling interest, net of costs			148,751
Distributions to noncontrolling interest	(45,961)	(14,250)	(18,970)
Preferred stock dividends	(15,098)	(11,276)
Derivative contracts, net	67,129
Other financings, net	(42,534)	(11,180)
Exercise of stock options/warrants	205	3,609	3
Net cash provided by financing activities	112,049	694,024	358,673
Effect of exchange rate changes on cash and cash equivalents	1,596	(189)	8,419
Increase (decrease) in cash and cash equivalents	(89,017)	45,734	(106,032)
Cash and cash equivalents, beginning of year	154,695	108,961	214,993
Cash and cash equivalents, end of year	$ 65,678	$ 154,695	$ 108,961