Consolidated Statements of Income (Loss) and Comprehensive Income (Loss) (USD $)	3 Months Ended															12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenue
Production																$ 463,491,000		$ 630,947,000		$ 800,543,000
Sales of purchased natural gas																64,913,000		62,405,000		86,645,000
Net derivative gains																29,928,000		11,444,000		51,780,000
Other																3,230,000		4,242,000		4,655,000
Total revenue																561,562,000		709,038,000		943,623,000
Operating expense
Lease operating																82,265,000		95,333,000		102,874,000
Gathering, processing and transportation																148,569,000		166,316,000		190,560,000
Production and ad valorem taxes																17,066,000		25,395,000		29,226,000
Cost of purchased natural gas																64,840,000		62,041,000		85,398,000
Depletion, depreciation and accretion																62,612,000		163,624,000		225,763,000
Impairment																1,863,000		2,625,928,000		107,059,000
General and administrative																55,306,000		75,697,000		79,582,000
Other operating																3,725,000		1,562,000		557,000
Total expense																436,246,000		3,215,896,000		821,019,000
Gain on Tokyo Gas Transaction																				0
Crestwood earn-out																				0
Operating income (loss)	13,575,000	[1]	60,049,000	[2]	394,894,000	[3]	(3,874,000)	(468,213,000)	[4]	(576,551,000)	[5]	(1,153,012,000)	[6]	(267,985,000)	[7]	464,644,000		(2,465,761,000)		122,604,000
Loss from earnings of BBEP																0		0		(8,439,000)
Other income (expense) - net																(17,384,000)		1,108,000		219,768,000
Fortune Creek accretion																(19,245,000)		(19,472,000)		0
Interest expense																(251,847,000)		(164,051,000)		(186,024,000)
Income (loss) before income taxes																176,168,000		(2,648,176,000)		147,909,000
Income tax (expense) benefit																(14,550,000)		295,570,000		(57,863,000)
Net income (loss)																161,618,000		(2,352,606,000)		90,046,000
Other comprehensive income (loss)
Net change in derivative fair value - net of income tax																0		74,384,000		156,160,000
Foreign currency translation adjustment																(4,681,000)		412,000		(13,364,000)
Reclassification adjustments related to settlements of derivative contracts into production revenue- net of income tax																(46,931,000)		(128,161,000)		(58,125,000)
Other comprehensive income (loss)																(51,612,000)		(53,365,000)		84,671,000
Comprehensive income (loss)																110,006,000		(2,405,971,000)		174,717,000
Earnings (loss) per common share - basic	$ (0.18)		$ 0.06		$ 1.37		$ (0.35)	$ (3.22)		$ (4.65)		$ (4.72)		$ (1.24)		$ 0.92		$ (13.83)		$ 0.53
Earnings (loss) per common share - diluted	$ (0.18)		$ 0.06		$ 1.37		$ (0.35)	$ (3.22)		$ (4.65)		$ (4.72)		$ (1.24)		$ 0.92	[8]	$ (13.83)	[8]	$ 0.52	[8]
Tokyo Gas [Member]
Operating expense
Gain on Tokyo Gas Transaction					333,200,000											339,328,000		0		0
Crestwood earn-out																339,328,000
kwk_CrestwoodLP [Member]
Operating expense
Crestwood earn-out																$ 0		$ 41,097,000		$ 0

[1] Operating income for the fourth quarter of 2013 includes a decrease of $5.9 million to correct for immaterial items which pertain to prior 2013 quarters. These items include an adjustment to non-cash expense to settle litigation recognized in the first quarter of 2013 of $3.0 million, non-cash decrease in the gain related to the Tokyo Gas Transaction of $1.7 million arising from a change in the amount of surface real estate conveyed to TGBR, increase in the amortization of deferred financing costs and original issue discount of $0.8 million and strategic transaction fees of $0.5 million arising in the second quarter of 2013.

[2] Operating income for the third quarter of 2013 includes an increase of $8.2 million to correct for immaterial items which pertain to earlier quarters in 2013, comprised of an increase to the gain related to the Tokyo Gas Transaction of $7.8 million arising from a change to the amount of unevaluated properties allocated to TGBR

[3] Operating income for the second quarter of 2013 includes gains of $333.2 million related to the Tokyo Gas Transaction which was subsequently adjusted in later quarters to be a gain of $339.3 million. The period also includes an immaterial correction of $3.6 million for equity-based compensation granted to retirement-eligible employees whose awards required no future service at the time of grant but which expense was being recognized over multiple periods. The impact to the first quarter of 2013 expense was $1.2 million and the impact to 2012 and prior years was $2.4 million.

[4] Operating loss for the fourth quarter of 2012 includes charges for impairment of $451.5 million and $102.8 million for our U.S. and Canadian oil and gas properties, respectively. Operating loss also includes a $2.9 million impairment charge related to non-oil and gas properties. Net loss includes a valuation allowance for Canada of $61.3 million.

[5] Operating loss for the third quarter of 2012 includes charges for impairment of $479.9 million and $66.3 million for our U.S. and Canadian oil and gas properties, respectively. Operating loss also includes a $4.9 million impairment charge for other property and equipment in Colorado. Net loss includes a valuation allowance for the U.S. of

[6] Operating loss for the second quarter of 2012 includes charges for impairment of $1,042.7 million and $157.0 million for our U.S. and Canadian oil and gas properties, respectively.

[7] Operating loss for the first quarter of 2012 includes charges for impairment of $178.0 million and $139.9 million for our U.S. and Canadian oil and gas properties, respectively.

[8] For 2013, 5.6 million shares associated with our stock options and 0.2 million shares associated with our unvested restricted stock units were antidilutive and, therefore, excluded from the diluted share calculations. For 2012, 5.0 million shares associated with our stock options and 0.3 million shares associated with our unvested restricted stock units were antidilutive and, therefore, excluded from the diluted share calculations. For 2011, the effects of 9.8 million shares associated with our convertible debentures for the period outstanding were antidilutive, and 1.9 million shares associated with our stock options and 0.1 million shares associated with our unvested restricted stock units were antidilutive and, therefore, excluded from the diluted share calculations.