Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2013

Retirement Plans

Components of net periodic benefit cost

	Pension Benefits						Post-retirement Benefits
	Three Months Ended						Three Months Ended
	March 31,						March 31,
(in millions)	2013			2012			2013		2012
Service cost	$	1.3		$	1.2		$	—	$	—
Interest cost	1.9			2.5			—		0.1
Expected return on plan assets	(3.0		)	(3.5		)	—		—
Amortization of unrecognized loss	1.4			1.3			0.1		—
Net periodic benefit cost	$	1.6		$	1.5		$	0.1	$	0.1