CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues:
Oil, natural gas, and natural gas liquids sales	$ 135,694		$ 186,593	$ 294,595	$ 352,903
Interest and other	37		278	69	830
Equity earnings in subsidiaries	0		0	0	0
Total revenues	135,731		186,871	294,664	353,733
Costs, expenses, and other:
Lease operating expenses	27,134		23,483	54,741	47,113
Other production expenses	10,555		16,070	25,680	31,327
General and administrative	16,421		13,360	31,805	29,180
Depreciation, depletion, and amortization	72,987		52,360	139,957	100,904
Ceiling test write-down of oil and natural gas properties	348,976	34,800	0	383,793	0
Interest expense	34,317		37,819	67,709	75,856
Realized and unrealized gains on derivative instruments, net	(34,015)		(40,917)	(63,539)	(4,671)
Other, net	3,455		8,835	30,375	12,457
Total costs, expenses, and other	479,830		111,010	670,521	292,166
Earnings (loss) from continuing operations before income taxes	(344,099)		75,861	(375,857)	61,567
Income tax	167,074		46,757	167,989	42,384
Net earnings (loss) from continuing operations	(511,173)		29,104	(543,846)	19,183
Net earnings from discontinued operations	0		9,870	0	16,461
Net earnings (loss)	(511,173)		38,974	(543,846)	35,644
Less: net earnings attributable to noncontrolling interest	0		64	0	64
Net earnings (loss) attributable to Forest Oil Corporation	(511,173)		38,910	(543,846)	35,580
Comprehensive income (loss)	(510,987)		41,448	(543,473)	46,333
Parent Company
Revenues:
Oil, natural gas, and natural gas liquids sales	99,798		136,349	206,621	253,362
Interest and other	909		541	1,687	1,348
Equity earnings in subsidiaries	9,195		25,743	(7,599)	51,735
Total revenues	109,902		162,633	200,709	306,445
Costs, expenses, and other:
Lease operating expenses	22,153		19,733	45,972	40,269
Other production expenses	10,594		13,198	24,391	25,344
General and administrative	15,595		12,186	29,959	27,054
Depreciation, depletion, and amortization	53,534		38,989	101,403	75,063
Ceiling test write-down of oil and natural gas properties	348,976		0	348,976	0
Interest expense	34,316		37,819	67,708	75,856
Realized and unrealized gains on derivative instruments, net	(26,320)		(39,968)	(50,927)	(4,172)
Other, net	1,335		7,793	26,567	10,249
Total costs, expenses, and other	460,183		89,750	594,049	249,663
Earnings (loss) from continuing operations before income taxes	(350,281)		72,883	(393,340)	56,782
Income tax	160,892		33,909	150,506	21,138
Net earnings (loss) from continuing operations	(511,173)		38,974	(543,846)	35,644
Net earnings from discontinued operations	0		0	0	0
Net earnings (loss)	(511,173)		38,974	(543,846)	35,644
Less: net earnings attributable to noncontrolling interest	0		0	0	0
Net earnings (loss) attributable to Forest Oil Corporation	(511,173)		38,974	(543,846)	35,644
Comprehensive income (loss)	(510,987)		41,448	(543,473)	46,333
Guarantor Subsidiary
Revenues:
Oil, natural gas, and natural gas liquids sales	35,485		49,530	87,091	98,246
Interest and other	(1,387)		(1,019)	572	62
Equity earnings in subsidiaries	0		0	0	0
Total revenues	34,098		48,511	87,663	98,308
Costs, expenses, and other:
Lease operating expenses	4,891		3,640	8,579	6,628
Other production expenses	(86)		2,837	1,191	5,923
General and administrative	620		604	1,351	1,213
Depreciation, depletion, and amortization	19,015		12,850	37,683	24,942
Ceiling test write-down of oil and natural gas properties	0		0	0	0
Interest expense	(1,523)		(1,149)	188	(192)
Realized and unrealized gains on derivative instruments, net	(7,604)		(903)	(12,451)	(498)
Other, net	107		20	197	(21)
Total costs, expenses, and other	15,420		17,899	36,738	37,995
Earnings (loss) from continuing operations before income taxes	18,678		30,612	50,925	60,313
Income tax	7,489		13,699	19,917	22,672
Net earnings (loss) from continuing operations	11,189		16,913	31,008	37,641
Net earnings from discontinued operations	0		0	0	0
Net earnings (loss)	11,189		16,913	31,008	37,641
Less: net earnings attributable to noncontrolling interest	0		0	0	0
Net earnings (loss) attributable to Forest Oil Corporation	11,189		16,913	31,008	37,641
Comprehensive income (loss)	11,189		16,913	31,008	37,641
Combined Non-Guarantor Subsidiaries
Revenues:
Oil, natural gas, and natural gas liquids sales	411		714	883	1,295
Interest and other	0		0	0	0
Equity earnings in subsidiaries	0		0	0	0
Total revenues	411		714	883	1,295
Costs, expenses, and other:
Lease operating expenses	90		110	190	216
Other production expenses	47		35	98	60
General and administrative	206		570	495	913
Depreciation, depletion, and amortization	438		521	871	899
Ceiling test write-down of oil and natural gas properties	0		0	34,817	0
Interest expense	1,009		393	2,003	772
Realized and unrealized gains on derivative instruments, net	(91)		(46)	(161)	(1)
Other, net	2,013		1,022	3,611	2,229
Total costs, expenses, and other	3,712		2,605	41,924	5,088
Earnings (loss) from continuing operations before income taxes	(3,301)		(1,891)	(41,041)	(3,793)
Income tax	(1,307)		(851)	(2,434)	(1,426)
Net earnings (loss) from continuing operations	(1,994)		(1,040)	(38,607)	(2,367)
Net earnings from discontinued operations	0		9,870	0	16,461
Net earnings (loss)	(1,994)		8,830	(38,607)	14,094
Less: net earnings attributable to noncontrolling interest	0		64	0	64
Net earnings (loss) attributable to Forest Oil Corporation	(1,994)		8,766	(38,607)	14,030
Comprehensive income (loss)	(1,994)		8,830	(38,607)	14,094
Eliminations
Revenues:
Oil, natural gas, and natural gas liquids sales	0		0	0	0
Interest and other	515		756	(2,190)	(580)
Equity earnings in subsidiaries	(9,195)		(25,743)	7,599	(51,735)
Total revenues	(8,680)		(24,987)	5,409	(52,315)
Costs, expenses, and other:
Lease operating expenses	0		0	0	0
Other production expenses	0		0	0	0
General and administrative	0		0	0	0
Depreciation, depletion, and amortization	0		0	0	0
Ceiling test write-down of oil and natural gas properties	0		0	0	0
Interest expense	515		756	(2,190)	(580)
Realized and unrealized gains on derivative instruments, net	0		0	0	0
Other, net	0		0	0	0
Total costs, expenses, and other	515		756	(2,190)	(580)
Earnings (loss) from continuing operations before income taxes	(9,195)		(25,743)	7,599	(51,735)
Income tax	0		0	0	0
Net earnings (loss) from continuing operations	(9,195)		(25,743)	7,599	(51,735)
Net earnings from discontinued operations	0		0	0	0
Net earnings (loss)	(9,195)		(25,743)	7,599	(51,735)
Less: net earnings attributable to noncontrolling interest	0		0	0	0
Net earnings (loss) attributable to Forest Oil Corporation	(9,195)		(25,743)	7,599	(51,735)
Comprehensive income (loss)	$ (9,195)		$ (25,743)	$ 7,599	$ (51,735)