Income Taxes - Changes in Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Roll Forward]
Balance at beginning of period	$ 1,308.9	$ 1,282.2	$ 1,328.4
Balance at end of period	1,402.8	1,308.9	1,282.2
Net tax expense related to operations
Valuation Allowance [Roll Forward]
Changes in valuation allowances	60.9	23.8	59.0
Translation adjustments
Valuation Allowance [Roll Forward]
Changes in valuation allowances	8.8	2.9	26.1
Business acquisitions and other
Valuation Allowance [Roll Forward]
Changes in valuation allowances	$ 24.2	$ 0.0	$ (131.3)