Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2011

The majority of retirement-benefit assets were invested as follows:



	Actual Allocation				Policy Range
	Year Ended December 31,
	2011		2010		2011	2010
Total domestic equity securities	35	%	41	%	35-45%	35-45%
Foreign equity securities
Developed market foreign equity securities	20	%	25	%	—	—
Emerging market foreign equity securities	4	%	7	%	—	—
Total foreign securities	24	%	32	%	25-35%	25-35%
Debt securities
Investment grade intermediate term debt	5	%	4	%	—	—
Investment grade long-term debt	17	%	13	%	—	—
Below-investment grade debt	9	%	9	%	—	—
Total debt securities	31	%	26	%	25-35%	25-35%
Inflation protection securities	9	%	—	%	0-10%	—%
Cash and short-term investments	1	%	1	%	0-3%	0-3%

The following tables set forth by level, within the fair value hierarchy, pension and postretirement benefit assets fair value:



	Investments at Fair Value
	December 31, 2011
	Level 1		Level 2		Total
	(in millions)
Domestic equity mutual fund	$	2.1	$	—	$	2.1
Fixed income mutual funds	62.7		—		62.7
Inflation protection mutual fund	19.5		—		19.5
Corporate bonds	—		1.9		1.9
U.S. government securities	—		3.1		3.1
Commingled funds
Cash equivalent funds	—		3.0		3.0
Domestic equity index fund	—		145.8		145.8
Foreign equity growth fund	—		28.2		28.2
Foreign equity index funds	—		43.0		43.0
Corporate debt funds	—		65.7		65.7
Inflation protection fund	—		18.7		18.7
Foreign equity growth 103-12 investment entity	—		30.2		30.2
Total	$	84.3	$	339.6	$	423.9



	Investments at Fair Value
	December 31, 2010
	Level 1		Level 2		Total
	(in millions)
Domestic equity mutual fund	$	2.6	$	—	$	2.6
Fixed income mutual funds	53.7		—		53.7
Corporate bonds	—		2.0		2.0
U.S. government securities	—		3.2		3.2
Commingled funds
Cash equivalent funds	—		3.5		3.5
Domestic equity index fund	—		160.9		160.9
Foreign equity growth fund	—		52.7		52.7
Foreign equity index funds	—		36.7		36.7
Corporate debt funds	—		45.7		45.7
Foreign equity growth 103-12 investment entity	—		37.1		37.1
Total	$	56.3	$	341.8	$	398.1

The qualified pension projected benefit obligation was measured using the following assumptions at December 31:



	2011		2010
Discount rate	4.80	%	5.75	%
Rate of increase in compensation	5.50		4.00
Long-term return on assets	7.25		7.25

The nonqualified pension projected benefit obligation was measured using the following assumptions at December 31:



	2011		2010
Discount rate	3.30	%	5.75	%
Rate of increase in compensation	5.50		4.00
Long-term return on assets	7.25		7.25

The postretirement benefit accumulated benefit obligation was measured using the following assumptions at December 31:

Plan obligations and fair value of all plan assets are shown in the following table:



	Pension						Postretirement Benefits
	2011			2010			2011			2010
	(in millions)
Change in benefit obligation
Benefit obligation at beginning of year	$	492.4		$	486.6		$	77.9		$	76.3
Service cost	9.3			9.3			0.5			0.6
Interest cost	28.5			28.7			4.2			4.4
Change in plan assumptions	122.3			70.5			14.7			4.5
Actuarial (gain) loss	13.2			(11.0		)	(0.9		)	1.1
Curtailment charge	—			(18.3		)	—			(4.4		)
Transfer to QEP due to Spinoff	—			(53.6		)	—			—
Benefits paid	(18.8		)	(19.8		)	(7.7		)	(4.6		)
Benefit obligation at end of year	646.9			492.4			88.7			77.9

Change in plan assets
Fair value of plan assets at beginning of year	359.9			318.6			38.4			35.8
Actual gain (loss) on plan assets	2.5			43.7			(0.7		)	4.1
Company contributions to the plan	46.4			42.6			4.0			3.1
Transfer to QEP due to Spinoff	—			(25.2		)	—			—
Benefits paid	(18.8		)	(19.8		)	(7.7		)	(4.6		)
Fair value of plan assets at end of year	390.0			359.9			34.0			38.4
Underfunded status (current and long-term)	$	(256.9	)	$	(132.5	)	$	(54.7	)	$	(39.5	)

Estimated benefit-plan payments for the five years following 2011 and the subsequent five years aggregated are as follows:

The pension and other postretirement benefits expense for 2010 and 2009 include eligible employees and retirees of both Questar and QEP.



	Pension Year Ended December 31,									Postretirement Benefits Year Ended December 31,
	2011			2010			2009			2011			2010			2009
	(in millions)
Service cost	$	9.3		$	9.3		$	9.9		$	0.5		$	0.6		$	0.7
Interest cost	28.5			28.7			29.6			4.2			4.4			4.6
Expected return on plan assets	(26.0		)	(24.4		)	(25.3		)	(2.6		)	(2.4		)	(2.2		)
Prior service and other costs	1.1			1.1			1.2			1.9			1.9			1.9
Recognized net actuarial loss	12.1			8.2			6.6			0.3			0.6			0.9
Curtailment charges	0.8			2.4			—			—			0.3			—
Special-termination benefits	—			—			2.0			—			—			—
Accretion of regulatory liability	—			—			—			0.8			0.8			0.8
Periodic expense	$	25.8		$	25.3		$	24.0		$	5.1		$	6.2		$	6.7

Assumptions at January 1, used to calculate the qualified and nonqualified pension benefits expense for the years, were as follows:



	2011		2010 - 2^nd Half		2010 - 1^st Half		2009
Discount rate	5.75	%	5.75	%	6.50	%	6.50	%
Rate of increase in compensation	4.00		4.00		4.00		4.00
Long-term return on assets	7.25		7.25		7.25		7.50

Assumptions at January 1, used to calculate the postretirement benefits expense for the years, were as follows: