Employee Benefit Plans Change in Projected Benefit Obligation Amount (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefit Plans
Defined Benefit Plan, Change in Benefit Obligation
Benefit Obligation at Beginning of Year	$ 147.9	$ 160.4
Service Cost	0.0	0.0	$ 0.0
Interest Cost	5.9	7.2	7.2
Plan Participant Contributions	0.2	4.0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(4.2)	(4.4)
Benefits and Expenses Paid	(10.3)	(15.6)
Plan Amendments	0.0	(3.7)
Change in Foreign Exchange Rates	0.0	0.0
Benefit Obligation at End of Year	139.5	147.9	160.4
Defined Benefit Plan, Change in Fair Value of Plan Assets
Fair Value of Plan Assets at Beginning of Year	10.8	11.2
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	0.1	0.1
Employer Contributions to Defined Benefit Plan	9.7	11.1
Plan Participant Contributions	0.2	4.0
Benefits and Expenses Paid	(10.3)	(15.6)
Effect of Foreign Exchange Rates on Plan Assets	0.0	0.0
Fair Value of Plan Assets at End of Year	10.5	10.8	11.2
Funded Status of Plan	129.0	137.1
Domestic Plan | Pension Plan
Defined Benefit Plan, Change in Benefit Obligation
Benefit Obligation at Beginning of Year	1,955.3	1,808.2
Service Cost	7.9	7.0	3.8
Interest Cost	84.5	85.2	82.2
Plan Participant Contributions	0.0	0.0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	159.3	123.6
Benefits and Expenses Paid	(77.7)	(68.7)
Plan Amendments	7.6	0.0	(7.5)
Change in Foreign Exchange Rates	0.0	0.0
Benefit Obligation at End of Year	2,136.9	1,955.3	1,808.2
Accumulated Benefit Obligation	2,136.9	1,955.3
Defined Benefit Plan, Change in Fair Value of Plan Assets
Fair Value of Plan Assets at Beginning of Year	1,454.1	1,403.3
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	198.5	112.3
Employer Contributions to Defined Benefit Plan	7.7	7.2
Plan Participant Contributions	0.0	0.0
Benefits and Expenses Paid	(77.7)	(68.7)
Effect of Foreign Exchange Rates on Plan Assets	0.0	0.0
Fair Value of Plan Assets at End of Year	1,582.6	1,454.1	1,403.3
Funded Status of Plan	554.3	501.2
Foreign Plan | Pension Plan
Defined Benefit Plan, Change in Benefit Obligation
Benefit Obligation at Beginning of Year	223.0	203.8
Service Cost	0.0	0.0	0.0
Interest Cost	6.2	7.0	7.9
Plan Participant Contributions	0.0	0.0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	1.7	55.0
Benefits and Expenses Paid	(8.3)	(4.5)
Plan Amendments	0.0	0.0
Change in Foreign Exchange Rates	21.2	(38.3)
Benefit Obligation at End of Year	243.8	223.0	203.8
Accumulated Benefit Obligation	234.3	213.4
Defined Benefit Plan, Change in Fair Value of Plan Assets
Fair Value of Plan Assets at Beginning of Year	228.4	231.5
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	11.6	42.5
Employer Contributions to Defined Benefit Plan	0.0	0.0
Plan Participant Contributions	0.0	0.0
Benefits and Expenses Paid	(8.3)	(4.5)
Effect of Foreign Exchange Rates on Plan Assets	21.8	(41.1)
Fair Value of Plan Assets at End of Year	253.5	228.4	$ 231.5
Funded Status of Plan	$ (9.7)	$ (5.4)