Pension and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2011

Pension and Other Postretirement Benefits [Abstract]

Components of net periodic benefit cost

	Pension Benefits
	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2011			2010			2011			2010
				(in millions)
Components of net periodic benefit cost:
Service cost	$	0.6		$	0.9		$	1.2		$	1.8
Interest cost		8.4			9.6			16.8			19.5
Expected return on plan assets		(10.9	)		(10.7	)		(21.8	)		(21.5	)
Amortization of prior service cost		(0.7	)		(0.6	)		(1.4	)		(1.3	)
Recognized actuarial loss		5.0			5.3			9.9			10.7
Net periodic benefit cost	$	2.4		$	4.5		$	4.7		$	9.2

	Other Postretirement Benefits
	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2011			2010			2011			2010
				(in millions)
Components of net periodic benefit cost:
Interest cost	$	0.9		$	1.2		$	1.8		$	2.4
Amortization of prior service cost		(0.5	)		(0.5	)		(1.0	)		(1.0	)
Recognized actuarial gain		(0.8	)		(0.5	)		(1.6	)		(1.0	)
Net periodic benefit cost (gain)	$	(0.4	)	$	0.2		$	(0.8	)	$	0.4