Employee Retirement Plans (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Expense Components
Service cost	$ 0.5	$ 0.5	$ 1.1
Interest	20.0	20.2	18.5
Expected return on plan assets	(30.5)	(31.0)	(26.6)
Amortization of actuarial loss	5.0	2.1	4.9
Prior service cost	0.0	0.0	0.1
Defined benefit expense	(5.0)	(8.2)	(2.0)
Profit sharing	18.7	17.4	12.3
Multiemployer plan	2.4	0.8	0.0
Net expense	$ 16.1	$ 10.0	$ 10.3