Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Total assets, recurring fair value measurements	$ 22.1	$ 5.5
Total liability, recurring fair value measurements	19.2	21.6
Total debt	1,403.2	1,485.2
Total financial instruments not carried at fair value	1,403.2	1,485.2
Fair Value, Inputs, Level 1 [Member]
Total assets, recurring fair value measurements	0.0	0.0
Total liability, recurring fair value measurements	0.0	0.0
Total debt	0.0	0.0
Total financial instruments not carried at fair value	0.0	0.0
Fair Value, Inputs, Level 2 [Member]
Total assets, recurring fair value measurements	22.1	5.5
Total liability, recurring fair value measurements	19.2	21.6
Total debt	1,403.2	1,485.2
Total financial instruments not carried at fair value	1,403.2	1,485.2
Fair Value, Inputs, Level 3 [Member]
Total assets, recurring fair value measurements	0.0	0.0
Total liability, recurring fair value measurements	0.0	0.0
Total debt	0.0	0.0
Total financial instruments not carried at fair value	0.0	0.0
Fair Value, Measurements, Recurring [Member]
Investments	14.3
Deferred compensation and other retirement plans	19.1	20.9
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Investments	0.0
Deferred compensation and other retirement plans	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Investments	14.3
Deferred compensation and other retirement plans	19.1	20.9
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Investments	0.0
Deferred compensation and other retirement plans	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Interest Rate Swap [Member]
Derivative Asset, Fair Value, Gross Asset	5.7	5.3
Fair Value, Measurements, Recurring [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Asset, Fair Value, Gross Asset	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Asset, Fair Value, Gross Asset	5.7	5.3
Fair Value, Measurements, Recurring [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Asset, Fair Value, Gross Asset	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]
Derivative Asset, Fair Value, Gross Asset	2.1	0.2
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0.1	0.7
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Asset, Fair Value, Gross Asset	0.0	0.0
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Asset, Fair Value, Gross Asset	2.1	0.2
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0.1	0.7
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Asset, Fair Value, Gross Asset	0.0	0.0
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	$ 0.0	$ 0.0