Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Plan Assets
Expected contributions to the defined benefit pension plan in 2016	$ 1.8
Expense provision for 401 (k) plans	4.0	$ 3.6	$ 3.8
Hedge Funds [Member]
Pension Plan Assets
Investments in hedge funds which do not have readily determinable fair values	44.1	45.5
Employee Pension Plans [Member]
Pension Plan Assets
Other comprehensive gain (loss)	0.7	$ 13.9	$ 18.7
Amount to be amortized from other comprehensive loss into cost in 2016	$ 1.7
Expected return on assets (as a percent)	6.50%	6.75%	6.75%
Other Multiemployer Pension Plans [Member]
Pension Plan Assets
Multiemployer Plan, Period Contributions	$ 40.6	$ 32.7	$ 31.4