Employee Benefits (Tables)

9 Months Ended

Sep. 30, 2011

Employee Benefits [Abstract]

Components of qualified and nonqualified pension expense, and postretirement benefits expense, included in net income

The 2010 amounts have not been recast for the Spinoff of QEP.

	3 Months Ended Sept. 30,						9 Months Ended Sept. 30,						12 Months Ended Sept. 30,
	2011			2010			2011			2010			2011			2010
	(in millions)
Service cost	$	2.2		$	2.3		$	6.6		$	7.2		$	8.7		$	9.6
Interest cost		7.1			6.5			21.3			22.3			27.7			29.9
Expected return on plan assets		(6.3	)		(5.6	)		(18.9	)		(18.4	)		(24.9	)		(24.7	)
Prior service and other costs		0.3			0.3			0.9			0.9			1.1			1.2
Recognized net-actuarial loss		2.6			2.8			7.8			6.3			9.7			7.9
Curtailment costs		-			1.1			-			1.4			1.0			0.1
Special-termination benefits		-			-			-			-			-			2.0
Pension expense	$	5.9		$	7.4		$	17.7		$	19.7		$	23.3		$	26.0

 Postretirement benefit expense components are listed in the table below. The 2010 amounts have not been recast for the Spinoff of QEP.

	3 Months Ended Sept. 30,						9 Months Ended Sept. 30,						12 Months Ended Sept. 30,
	2011			2010			2011			2010			2011			2010
	(in millions)
Service cost	$	0.2		$	0.2		$	0.5		$	0.5		$	0.6		$	0.6
Interest cost		1.1			1.0			3.3			3.4			4.3			4.5
Expected return on plan assets		(0.7	)		(0.7	)		(2.0	)		(1.8	)		(2.6	)		(2.3	)
Amortization of transition obligation		0.4			0.5			1.3			1.4			1.8			1.9
Amortization of losses		0.2			0.1			0.5			0.5			0.6			0.7
Curtailment costs		-			-			-			-			0.3			-
Accretion of regulatory liability		0.2			0.2			0.6			0.6			0.8			0.8
Postretirement benefits expense	$	1.4		$	1.3		$	4.2		$	4.6		$	5.8		$	6.2