Pension and Other Postemployment Benefit (OPEB) Plans (Tables)

9 Months Ended

Sep. 30, 2013

Compensation and Retirement Disclosure [Abstract]

Components of net periodic expense of Pension and OPEB plans

The following table presents the components of net periodic expense (benefit) of the Company’s Pension and Other Postretirement plans:

	Pension Benefits						Other Benefits
	Three Months Ended September 30,						Three Months Ended September 30,
(in millions)	2013			2012			2013			2012
Service cost	$	0.6		$	0.5		$	—		$	—
Interest cost	1.7			1.8			—			—
Expected return on plan assets	(2.2		)	(2.2		)	—			—
Amortization of net loss (gain)	0.6			0.9			(3.2		)	(3.1		)
Amortization of prior service (credit)	—			—			(0.5		)	(0.6		)
Curtailment (gain)	—			—			—			—
Net periodic expense (benefit)	$	0.7		$	1.0		$	(3.7	)	$	(3.7	)

	Pension Benefits						Other Benefits
	Nine Months Ended September 30,						Nine Months Ended September 30,
(in millions)	2013			2012			2013			2012
Service cost	$	1.7		$	1.7		$	—		$	—
Interest cost	5.1			5.5			—			0.1
Expected return on plan assets	(6.5		)	(6.4		)	—			—
Amortization of net loss (gain)	2.0			2.5			(9.6		)	(6.1		)
Amortization of prior service (credit)	(0.1		)	(0.1		)	(1.5		)	(3.4		)
Curtailment (gain)	—			—			—			(45.0		)
Net periodic expense (benefit)	$	2.2		$	3.2		$	(11.1	)	$	(54.4	)