Fair Value Disclosure Fair Value Disclosure - Impacts of Derivative Instrument on Statement of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest Expense	$ (47.1)	$ (42.2)	$ (93.6)	$ (82.1)
Amount of Loss (Gain) Reclassified from Accumulated Other Comprehensive Income into Income	6.6	(15.2)	(3.6)	(5.9)
Other Nonoperating Income (Expense)	(0.6)	(9.8)	(3.8)	(11.1)
Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss (Gain) Recognized in Other Comprehensive Income	4.2	(17.2)	(8.7)	(5.7)
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss (Gain) Recognized in Other Comprehensive Income	4.4	(17.2)	(8.6)	(6.4)
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss (Gain) Recognized in Other Comprehensive Income	(0.2)	0.0	(0.1)	0.7
Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss (Gain) Reclassified from Accumulated Other Comprehensive Income into Income	0.7	1.1	1.5	2.2
Gain (loss) on non-designated derivative contracts	0.0	0.0	0.0	0.0
Interest Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged items	(5.3)	1.8	(8.5)	7.6
Derivatives designated as hedging instruments	5.3	(1.8)	8.5	(7.6)
Interest Expense [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive income into income	(0.7)	(1.1)	(1.5)	(2.2)
Interest Expense [Member] | Cash Flow Hedging [Member] | Foreign Exchange Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive income into income	0.0	0.0	0.0	0.0
Other (Income) Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss (Gain) Reclassified from Accumulated Other Comprehensive Income into Income	5.9	(16.3)	(5.1)	(8.1)
Gain (loss) on non-designated derivative contracts	(1.9)	5.0	(2.7)	5.7
Other (Income) Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged items	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Other (Income) Expense [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive income into income	0.0	0.0	0.0	0.0
Other (Income) Expense [Member] | Cash Flow Hedging [Member] | Foreign Exchange Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive income into income	$ (5.9)	$ 16.3	$ 5.1	$ 8.1