For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Foreign exchange gains (losses)	$ (0.3)	$ (0.2)	$ (0.3)	$ 0.4
Deferred revenue contract liability	72.4		$ 72.4		$ 30.6
Performance obligation timing			We expect to recognize substantially all of these amounts in revenues within approximately 12 months.
Deferred revenue recognized	$ 6.7		$ 23.9
Maximum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Derivative term of contract			1 year
Sales Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Consolidated revenues, net (percent)	100.00%	100.00%	100.00%	100.00%
Contracts with customers \| Sales Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Consolidated revenues, net (percent)	80.00%		80.00%
Intra-entity Transactions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Foreign exchange gains (losses)	$ 43.7	$ (132.2)	$ (33.3)	$ (156.5)