Operations by Line of Business (Tables)

3 Months Ended

Mar. 31, 2015

Segment Reporting [Abstract]

Summary of operations by line of business

Following is a summary of operations by line of business:

	3 Months Ended						12 Months Ended
	March 31,						March 31,
	2015			2014			2015			2014
	(in millions)
Revenues from Unaffiliated Customers
Questar Gas	$	374.8		$	396.3		$	939.4		$	963.2
Wexpro	6.3			12.3			29.6			47.1
Questar Pipeline	46.8			48.0			189.0			189.2
Other	0.7			0.3			3.0			0.5
Total	$	428.6		$	456.9		$	1,161.0		$	1,200.0
Revenues from Affiliated Companies
Questar Gas	$	—		$	—		$	—		$	0.3
Wexpro	84.8			89.1			346.0			311.1
Questar Pipeline	19.4			19.3			73.8			76.5
Total	$	104.2		$	108.4		$	419.8		$	387.9
Operating Income (Loss)
Questar Gas	$	76.6		$	69.8		$	116.3		$	107.4
Wexpro	41.7			48.5			176.5			176.4
Questar Pipeline	27.4			30.1			114.9			35.4
Corporate and other	1.3			(0.1		)	(3.6		)	3.5
Total	$	147.0		$	148.3		$	404.1		$	322.7
Net Income (Loss)
Questar Gas	$	43.8		$	39.6		$	59.4		$	55.4
Wexpro	27.7			31.8			118.7			116.1
Questar Pipeline	13.9			15.7			58.8			8.1
Corporate and other	(0.8		)	(2.0		)	(10.9		)	(6.2		)
Total	$	84.6		$	85.1		$	226.0		$	173.4