Employee Benefits (Tables)

9 Months Ended

Sep. 30, 2013

Compensation and Retirement Disclosure [Abstract]

Pension and Other Postretirement Benefit Costs

	Pension
	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2013			2012			2013			2012
	(in millions)
Service cost	$	0.7		$	1.1		$	2.6		$	3.0
Interest cost	1.2			1.3			3.7			3.7
Expected return on plan assets	(0.9		)	(0.9		)	(2.9		)	(2.7		)
Amortization of prior service costs	1.2			1.3			3.7			3.9
Amortization of actuarial loss	0.5			0.6			1.7			1.0
Periodic expense	$	2.7		$	3.4		$	8.8		$	8.9

	Postretirement Benefits
	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2013		2012		2013		2012
	(in millions)
Service cost	$	0.1	$	0.1	$	0.1	$	0.1
Interest cost	—		—		0.2		0.2
Amortization of prior service costs	0.1		0.1		0.3		0.3
Recognized net actuarial loss	0.1		—		0.1		—
Periodic expense	$	0.3	$	0.2	$	0.7	$	0.6