Operations by Line of Business (Tables)

9 Months Ended

Sep. 30, 2012

Segment Reporting [Abstract]

Summary of continuing operations by line of business

Following is a summary of operations by line of business:

	3 Months Ended						9 Months Ended						12 Months Ended
	September 30,						September 30,						September 30,
	2012			2011			2012			2011			2012			2011
	(in millions)
Revenues from Unaffiliated Customers
Questar Gas	$	82.5		$	89.8		$	578.7		$	667.7		$	876.5		$	970.4
Wexpro	9.8			6.9			27.1			23.1			35.5			31.1
Questar Pipeline	49.5			50.0			150.1			148.8			198.7			200.8
Total	$	141.8		$	146.7		$	755.9		$	839.6		$	1,110.7		$	1,202.3
Revenues from Affiliated Companies
Questar Gas	$	0.5		$	0.4		$	2.3		$	2.2		$	3.4		$	2.7
Wexpro	69.3			64.4			204.6			186.4			271.8			247.5
Questar Pipeline	18.4			18.5			55.2			55.8			73.8			74.3
Total	$	88.2		$	83.3		$	262.1		$	244.4		$	349.0		$	324.5
Operating Income (Loss)
Questar Gas	$	(10.7	)	$	(7.9	)	$	52.6		$	56.6		$	90.1		$	95.8
Wexpro	41.0			37.7			117.9			108.3			155.3			143.1
Questar Pipeline	32.6			33.9			95.2			94.9			126.2			129.0
Corporate and other	0.7			0.1			1.4			0.5			2.1			0.2
Total	$	63.6		$	63.8		$	267.1		$	260.3		$	373.7		$	368.1
Net Income (Loss)
Questar Gas	$	(9.3	)	$	(7.9	)	$	23.3		$	25.9		$	43.5		$	48.0
Wexpro	26.4			25.6			76.5			71.6			100.1			94.3
Questar Pipeline	17.1			18.8			49.8			50.7			67.0			68.7
Corporate and other	(0.4		)	(0.4		)	(1.4		)	(1.9		)	(0.8		)	(1.0		)
Total	$	33.8		$	36.1		$	148.2		$	146.3		$	209.8		$	210.0