Accumulated Other Comprehensive Loss - Summary of Reclassifications of Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Actuarial gain (loss)	[1]	$ 0.0	$ 0.0	$ (0.8)	$ 1.2
Amortization of defined benefit pension items reclassified to net periodic pension cost:
Net loss	[1]	1.8	1.1	5.4	3.3
Prior service credit	[1]	(0.4)	(0.4)	(1.0)	(1.0)
Total before income tax		1.4	0.7	3.6	3.5
Income taxes		(0.5)	(0.3)	(1.4)	(1.4)
Other Comprehensive Income		$ 0.9	$ 0.4	$ 2.2	$ 2.1

[1] These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 10 for additional details).