Comprehensive Income (Tables)

3 Months Ended

Mar. 31, 2012

Schedule of Accumulated Other Comprehensive Income (Loss)

The components of consolidated accumulated other comprehensive income (loss) (AOCI), net of income taxes, as reported in Questar's Condensed Consolidated Balance Sheets, are shown below:

	Mar. 31, 2012			Mar. 31, 2011			Dec. 31, 2011
	(in millions)
Pension and other postretirement benefits	$	(202.8	)	$	(104.1	)	$	(202.8	)
Interest rate cash flow hedges	(23.4		)	—			(23.4		)
Long-term investment	0.1			0.1			0.1
Accumulated other comprehensive (loss)	$	(226.1	)	$	(104.0	)	$	(226.1	)

Questar Pipeline [Member]

Schedule of Accumulated Other Comprehensive Income (Loss)

The component of consolidated AOCI, net of income taxes, as reported in Questar Pipeline's Condensed Consolidated Balance Sheets, is shown below:

	Mar. 31, 2012			Mar. 31, 2011		Dec. 31, 2011
	(in millions)
Interest rate cash flow hedges	$	(23.4	)	$	—	$	(23.4	)
Accumulated other comprehensive (loss)	$	(23.4	)	$	—	$	(23.4	)