CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ 45.5		$ (3.7)
Other comprehensive (loss) income, net of tax:
Reclassification of previously deferred derivative gains(1)	0	[1]	(20.1)	[1]
Pension and other postretirement plans adjustments:
Amortization of net actuarial loss	0.1	[2]	0.4	[2]
Amortization of prior service cost	0.9	[3]	0.8	[3]
Total pension and other postretirement plans adjustments	1.0		1.2
Other comprehensive loss	1.0		(18.9)
Comprehensive (loss) income	46.5		(22.6)
Comprehensive income attributable to noncontrolling interests	(5.8)		(0.6)
Comprehensive (loss) income attributable to QEP	$ 40.7		$ (23.2)

[1] Presented net of income tax benefit of $11.9 million during the three months ended March 31, 2013

[2] Presented net of income tax expense of $0.1 million during the three months ended March 31, 2014 and $0.2 million during the three months ended March 31, 2013, respectively.

[3] Presented net of income tax expense of $0.4 million during the three months ended March 31, 2014 and $0.5 million during the three months ended March 31, 2013, respectively.