Income Taxes - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Net deferred tax liabilities	$ 137.8	$ 225.4
Impact of Swiss step up assets	(59.1)
Increase in valuation allowance	$ 7.4
Transition tax on accumulated foreign earnings			0.155
Effective income tax rate, tax cuts and jobs act			0.08
TCJA, effect on income tax expense, transition tax				$ 36.0
Effective tax rate	210.60%	21.00%	23.40%
Net discrete tax charges (in basis points)	16.06%	2.40%	0.60%
Employee service share-based compensation, tax benefit from exercise of stock options	$ 4.4	$ 8.4	$ 5.1
Excess tax benefit from share-based compensation, operating activities	$ 2.3	$ 6.2	$ 3.3
Other adjustments (in basis points)	7.70%	2.30%	1.10%
Net operating loss carryforwards	$ 159.5
Operating loss carryforwards, valuation allowances	117.5
Gross unrecognized tax benefits	7.1	$ 9.1	$ 27.2	$ 37.4
Recognized potential interest and penalties	0.0	0.6	$ 0.5
Unrecognized tax benefits that would impact effective tax rate	9.0
Estimated reduction in unrecognized tax benefits within twelve months	2.8
Continuing operations
Gross unrecognized tax benefits	7.1	9.1
Unrecognized tax benefits, net of offsetting indirect tax benefits	9.0	10.9
Potential interest and penalties	1.9	1.8
United States | Affiliated entity
Net deferred tax liabilities	122.5	147.8
Foreign tax | Affiliated entity
Net deferred tax liabilities	$ 15.3	$ 77.4