Pension and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2011

Pension and Other Postretirement Benefits [Abstract]

Components of net periodic benefit cost

	Pension Benefits
	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2011			2010			2011			2010
	(in millions)
Components of net periodic benefit cost:
Service cost	$	0.6		$	0.7		$	1.8		$	2.5
Interest cost		8.4			9.1			25.2			28.6
Expected return on plan assets		(10.9	)		(10.6	)		(32.7	)		(32.1	)
Amortization of prior service cost		(0.6	)		(0.7	)		(2.0	)		(2.0	)
Recognized actuarial loss		5.4			5.2			15.3			15.9
Net periodic benefit cost	$	2.9		$	3.7		$	7.6		$	12.9

	Other Postretirement Benefits
	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2011			2010			2011			2010
	(in millions)
Components of net periodic benefit cost:
Interest cost	$	0.9		$	1.1		$	2.7		$	3.5
Amortization of prior service cost		(0.5	)		(0.5	)		(1.5	)		(1.5	)
Recognized actuarial gain		(0.8	)		(0.5	)		(2.4	)		(1.5	)
Net periodic benefit cost (gain)	$	(0.4	)	$	0.1		$	(1.2	)	$	0.5