Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning of year		$ 133.4	$ 59.0	$ 28.6
Additions based on tax positions related to the current year		17.8	40.8	25.3
Additions for tax positions of prior years		79.7	39.0	7.8
Reductions for tax positions of prior years		(13.0)	(3.8)	(1.9)
Lapse of statute of limitations		(2.3)	(3.5)	(3.3)
Settlements		(0.3)	(6.4)	(0.6)
Effect of foreign currency translation		(0.4)	(0.9)
Effect of foreign currency translation				1.9
Separation related adjustments	[1]	0.0	9.2	1.2
Unrecognized tax benefits, end of year		$ 214.9	$ 133.4	$ 59.0

[1] (a) Unrecognized tax benefit reserves increased by $9 million and $1 million during the year ended December 31, 2018 and December 31, 2017, respectively, due primarily to unrecognized tax benefits from pre-Separation periods.