Operations by Line of Business (Tables)

3 Months Ended

Mar. 31, 2016

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,
	2016			2015			2016			2015
	(in millions)
Revenues from Unaffiliated Customers
Questar Gas	$	407.9		$	374.8		$	950.7		$	939.4
Wexpro	3.5			6.3			20.1			29.6
Questar Pipeline	43.0			46.8			184.1			189.0
Other	1.9			0.7			7.7			3.0
Total	$	456.3		$	428.6		$	1,162.6		$	1,161.0
Revenues from Affiliated Companies
Wexpro	$	79.8		$	84.8		$	314.1		$	346.0
Questar Pipeline	19.3			19.4			75.0			73.8
Total	$	99.1		$	104.2		$	389.1		$	419.8
Operating Income (Loss)
Questar Gas	$	83.4		$	76.6		$	129.4		$	116.3
Wexpro	39.7			41.7			145.4			176.5
Questar Pipeline	27.6			27.4			114.6			114.9
Corporate and other	(15.0		)	1.3			(26.3		)	(3.6		)
Total	$	135.7		$	147.0		$	363.1		$	404.1
Net Income (Loss)
Questar Gas	$	47.6		$	43.8		$	68.1		$	59.4
Wexpro	26.2			27.7			97.4			118.7
Questar Pipeline	14.2			13.9			59.9			58.8
Corporate and other	(9.5		)	(0.8		)	(22.8		)	(10.9		)
Total	$	78.5		$	84.6		$	202.6		$	226.0