CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
REVENUES
Natural gas sales	$ 667.4	$ 1,239.1	$ 1,205.3
Oil sales	532.6	324.2	198.1
NGL sales	322.1	309.8	142.6
Gathering, processing and other	181.6	200.8	156.6
Purchased gas, oil and NGL sales	646.1	1,085.3	598.0
Total Revenues	2,349.8	3,159.2	2,300.6
OPERATING EXPENSES
Purchased gas, oil and NGL expense	655.6	1,077.1	589.3
Lease operating expense	172.3	145.2	125.0
Natural gas, oil and NGL transport and other handling costs	148.9	102.2	54.2
Gathering, processing and other	88.0	107.3	83.2
General and administrative	266.6	123.2	107.2
Separation costs	0	0	13.5
Production and property taxes	103.4	105.4	82.5
Depreciation, depletion and amortization	904.9	765.4	643.4
Exploration expenses	11.2	10.5	23.0
Abandonment and impairment	133.4	218.4	46.1
Total Operating Expenses	2,484.3	2,654.7	1,767.4
Net gain from asset sales	1.2	1.4	12.1
OPERATING (LOSS) INCOME	(133.3)	505.9	545.3
Realized and unrealized gains on derivative contracts (See Note 6)	441.9	0	0
Interest and other income	6.6	4.1	2.3
Income from unconsolidated affiliates	6.8	5.5	3.0
Loss from early extinguishment of debt	(0.6)	(0.7)	(13.3)
Interest expense	(122.9)	(90.0)	(84.4)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	198.5	424.8	452.9
Income taxes	(66.5)	(154.4)	(167.0)
INCOME FROM CONTINUING OPERATIONS	132.0	270.4	285.9
Discontinued operations, net of income tax	0	0	43.2
NET INCOME	132.0	270.4	329.1
Net income attributable to noncontrolling interest	(3.7)	(3.2)	(2.9)
NET INCOME ATTRIBUTABLE TO QEP	$ 128.3	$ 267.2	$ 326.2
Earnings Per Common Share Attributable to QEP
Basic from continuing operations	$ 0.72	$ 1.51	$ 1.61
Basic from discontinued operations	$ 0.00	$ 0.00	$ 0.25
Basic total	$ 0.72	$ 1.51	$ 1.86
Diluted from continuing operations	$ 0.72	$ 1.50	$ 1.60
Diluted from discontinued operations	$ 0.00	$ 0.00	$ 0.24
Diluted total	$ 0.72	$ 1.50	$ 1.84
Weighted-average common shares outstanding
Used in basic calculation	177.8	176.5	175.3
Used in diluted calculation	178.7	178.4	177.3