Employee Retirement Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Components of Net Retirement Cost
Service cost	$ 0.2	$ 0.3	$ 0.4	$ 0.8
Interest	5.1	4.6	15.1	13.9
Expected return on plan assets	(7.8)	(6.6)	(23.2)	(19.9)
Amortization of actuarial loss	1.0	1.2	1.6	3.7
Defined benefit expense	(1.5)	(0.5)	(6.1)	(1.5)
Profit sharing	3.9	3.1	12.8	9.5
Multiemployer plan	0.3	0	0.3	0
Net expense	$ 2.7	$ 2.6	$ 7.0	$ 8.0