Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Financial Information Disclosure (Unaudited) [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

The following table provides a summary of unaudited quarterly financial information:

	First Quarter		Second Quarter			Third Quarter			Fourth Quarter			Year
	(in millions)
2012
Revenues	$	603.2	$	499.3		$	542.4		$	704.9		$	2,349.8
Operating income (loss)	49.5		(55.5		)	(12.6		)	(114.7		)	(133.3		)
Income (loss) before income taxes	244.7		0.3			(4.4		)	(42.1		)	198.5
Net income (loss) attributable to QEP	155.2		(0.7		)	(3.1		)	(23.1		)	128.3
Per share information attributable to QEP
Basic EPS attributable to QEP	$	0.87	$	—		$	(0.02	)	$	(0.13	)	$	0.72
Diluted EPS attributable to QEP	0.87		—			(0.02		)	(0.13		)	0.72

2011
Revenues	$	617.9	$	808.1	$	879.9	$	853.3		$	3,159.2
Operating income	137.1		168.9		183.4		16.5			505.9
Income (loss) before income taxes	116.5		147.7		161.5		(0.9		)	424.8
Net income (loss) attributable to QEP	73.2		92.8		101.5		(0.3		)	267.2
Per share information attributable to QEP
Basic EPS from continuing operations	$	0.42	$	0.52	$	0.58	$	(0.01	)	$	1.51
Basic EPS attributable to QEP	0.41		0.52		0.57		—			1.50