Discontinued Operations - Income Statement Impact of Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from unconsolidated affiliates				$ 0.0	$ (3.4)
Net income attributable to noncontrolling interest				$ 0.0	$ (10.8)
Earnings Per Share, Basic		$ (0.43)	$ (0.51)	$ (0.75)	$ (0.29)
Earnings Per Share, Diluted		(0.43)	$ (0.51)	(0.75)	$ (0.29)
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
NGL sales			$ 27.8		$ 65.8
Other revenue			34.9		76.8
Purchased gas and oil sales	[1]		(13.2)		(26.6)
Total Revenues			49.5		116.0
Purchased gas and oil expense	[1]		(13.3)		(27.1)
Lease operating expense	[1]		(2.0)		(3.1)
Natural gas, oil and NGL transportation and other handling costs	[1]		(13.1)		(29.5)
Gathering, processing and other			22.8		47.1
General and administrative			11.9		23.2
Production and property taxes			2.5		4.0
Depreciation, depletion and amortization			14.5		28.8
Total operating expenses			23.3		43.4
Gain (Loss) on Disposition of Property Plant Equipment			(0.1)		(0.1)
OPERATING INCOME			26.1		72.5
Income from unconsolidated affiliates			(1.1)		(3.3)
Interest expense			(0.7)		(1.3)
INCOME FROM DISCONTINUED OPERATIONS BEFORE INCOME TAXES			26.5		74.5
Income taxes			(7.7)		(22.9)
NET INCOME FROM DISCONTINUED OPERATIONS			18.8		51.6
Net income attributable to noncontrolling interest			(5.0)		(10.8)
NET INCOME FROM DISCONTINUED OPERATIONS, NET OF INCOME TAX			$ 13.8		$ 40.8
Earnings Per Share, Basic		$ 0.00	$ 0.08	$ 0.00	$ 0.23
Income from discontinued operations before income taxes attributable to QEP from QEP Midstream			$ 5.7		$ 12.5
Ownership percentage		57.80%		57.80%
Earnings Per Share, Diluted		$ 0.00	$ 0.08	$ 0.00	$ 0.23

[1] Includes discontinued intercompany eliminations