Pension and Post-retirement and Other Benefit Plans - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Aug. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Release of other postretirement benefit liability into other comprehensive income	$ 1.2
Net prior service cost amortized out of other comprehensive income	$ 1.8
Aggregate accumulated benefit obligation		$ 307.7	$ 343.1
Expected amortization of net actuarial loss from accumulated other comprehensive income (loss) next fiscal year		4.1
Expected future employer contributions		14.3
Employer matching contributions expense		$ 9.0	$ 9.6	$ 9.4