SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Comprehensive Income (Loss)) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Defined benefit postretirement plans
Net periodic benefit cost components arising during the period	$ 8,742,000		$ (3,191,000)	$ (11,058,000)
Actuarial losses reclassified from accumulated other comprehensive loss and included in net periodic benefit cost	1,374,000		1,155,000	641,000
Other comprehensive income (loss)	10,116,000		(2,036,000)	(10,417,000)
Foreign currency translation losses
Foreign currency translation losses arising during the period				(27,852,000)
Amounts reclassified from accumulated other comprehensive loss				0
Other comprehensive loss				(27,852,000)
Other comprehensive loss				(38,269,000)
Defined benefit postretirement plans
Net periodic benefit cost components arising during the period	0		(323,000)	3,979,000
Actuarial losses reclassified from accumulated other comprehensive loss and included in net periodic benefit cost	0		117,000	(231,000)
Other comprehensive income (loss)	0	[1]	(206,000)	3,748,000
Other comprehensive income tax expense offset by an equal decrease in the valuation allowance	3,600,000
Foreign currency translation losses
Foreign currency translation losses arising during the period				0
Amounts reclassified from accumulated other comprehensive loss				0
Other comprehensive loss				0
Other comprehensive loss				3,748,000
Defined benefit postretirement plans
Net periodic benefit cost components arising during the period	8,742,000		(3,514,000)	(7,079,000)
Actuarial losses reclassified from accumulated other comprehensive loss and included in net periodic benefit cost	1,374,000		1,272,000	410,000
Other comprehensive income (loss)	10,116,000		(2,242,000)	(6,669,000)
Foreign currency translation losses
Foreign currency translation losses arising during the period	0		0	(27,852,000)
Amounts reclassified from accumulated other comprehensive loss	0		0	0
Other comprehensive loss	0		0	(27,852,000)
Total other comprehensive income (loss)	10,116,000		(2,242,000)	(34,521,000)
Foreign Currency Translation
Balance at beginning of period	0		0	93,667,000
Changes in ownership interest in Lone Pine Resources				(72,132,000)
Other comprehensive losses arising during the period, before reclassifications, attributable to parent				(21,535,000)
Amounts reclassified from accumulated other comprehensive income, attributable to parent				0
Other comprehensive losses arising during the period, before reclassifications	0		0	(27,852,000)
Amounts reclassified from accumulated other comprehensive loss	0		0	0
Other comprehensive income (loss)	0		0	(21,535,000)
Balance at end of period	0		0	0
Defined Benefit Postretirement Plans
Balance at beginning of period	(20,514,000)		(18,272,000)	(11,603,000)
Changes in ownership interest in Lone Pine Resources				0
Other comprehensive losses arising during the period, before reclassifications	8,742,000		(3,514,000)	(7,079,000)
Amounts reclassified from accumulated other comprehensive loss	1,374,000		1,272,000	410,000
Other comprehensive income (loss)	10,116,000		(2,242,000)	(6,669,000)
Balance at end of period	(10,398,000)		(20,514,000)	(18,272,000)
Other Comprehensive Income (Loss) attributable to Forest Oil Corporation common shareholders
Balance at beginning of period	(20,514,000)		(18,272,000)	82,064,000
Changes in ownership interest in Lone Pine Resources				(72,132,000)
Other comprehensive losses arising during the period, before reclassifications	8,742,000		(3,514,000)	(28,614,000)
Amounts reclassified from accumulated other comprehensive loss	1,374,000		1,272,000	410,000
Other comprehensive income (loss)	10,116,000		(2,242,000)	(28,204,000)
Balance at end of period	$ (10,398,000)		$ (20,514,000)	$ (18,272,000)

[1] Tax expense of $3.6 million for the year ended December 31, 2013 is offset by an equal decrease in the valuation allowance.