Fair Value Measurements and the Fair Value Option - Schedule of Fair Value Measurements (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unconsolidated investments	$ 1,081.6	$ 1,107.4
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unconsolidated investments	1,081.6	1,107.4
Total	1,084.5	1,072.7
Recurring [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net currency derivative contracts	2.9	(34.7)
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unconsolidated investments	0.0	0.0
Total	0.0	0.0
Recurring [Member] | Level 1 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net currency derivative contracts	0.0	0.0
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unconsolidated investments	0.0	0.0
Total	2.9	(34.7)
Recurring [Member] | Level 2 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net currency derivative contracts	2.9	(34.7)
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unconsolidated investments	1,081.6	1,107.4
Total	1,081.6	1,107.4
Recurring [Member] | Level 3 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net currency derivative contracts	$ 0.0	$ 0.0