Asset Retirement Obligations (Tables)

3 Months Ended

Mar. 31, 2012

Asset Retirement Obligation [Abstract]

Changes in AROs

Changes in Questar's AROs from the Consolidated Balance Sheets for the three months ended March 31 were as follows:

	3 Months Ended
	March 31,
	2012			2011
	(in millions)
AROs at beginning of year	$	63.8		$	60.9
Accretion	0.7			0.7
Liabilities incurred	0.7			0.2
Revisions	(1.1		)	2.5
Liabilities settled	—			(0.1		)
AROs at March 31,	$	64.1		$	64.2