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

6 Months Ended

Jun. 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 June 30,						Three Months Ended June 30,
(in millions)	2013			2012			2013			2012
Service cost	$	0.5		$	0.6		$	—		$	—
Interest cost	1.7			1.9			—			0.1
Expected return on plan assets	(2.1		)	(2.1		)	—			—
Amortization of net loss (gain)	0.7			0.8			(3.2		)	(2.3		)
Amortization of prior service (credit)	(0.1		)	(0.1		)	(0.5		)	(1.0		)
Curtailment (gain)	—			—			—			(45.0		)
Net periodic expense (benefit)	$	0.7		$	1.1		$	(3.7	)	$	(48.2	)

	Pension Benefits						Other Benefits
	Six Months Ended June 30,						Six Months Ended June 30,
(in millions)	2013			2012			2013			2012
Service cost	$	1.1		$	1.2		$	—		$	—
Interest cost	3.4			3.7			—			0.1
Expected return on plan assets	(4.3		)	(4.2		)	—			—
Amortization of net loss (gain)	1.4			1.6			(6.4		)	(3.0		)
Amortization of prior service (credit)	(0.1		)	(0.1		)	(1.0		)	(2.8		)
Curtailment (gain)	—			—			—			(45.0		)
Net periodic expense (benefit)	$	1.5		$	2.2		$	(7.4	)	$	(50.7	)