Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan Assets
Expected contributions to the defined benefit pension plan in 2020	$ 4.0
Net actuarial loss	65.2	$ 56.5
Expense provision for 401 (k) plans	4.3	4.1	$ 4.2
Company Contributions	46.8	36.5	$ 36.6
Hedge fund investments
Pension Plan Assets
Investments in hedge funds which do not have readily determinable fair values	$ 10.6	$ 13.5
Employee Pension Plans
Pension Plan Assets
Discount rate (as a percent)	2.20%	3.10%
Expected return on assets (as a percent)	5.75%	5.75%	6.00%