Goodwill and Other Intangible Assets - Net - Other Intangible Assets, Net (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets, Net [Abstract]
Gross	$ 75.1	$ 71.8
Accumulated Amortization	49.8	40.7
Total	$ 25.3	$ 31.1
Developed Technologies [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	4 years	4 years
Finite-Lived Intangible Assets, Net [Abstract]
Gross	$ 53.3	$ 50.2
Accumulated Amortization	30.2	24.6
Total	$ 23.1	$ 25.6
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	4 years 1 month 6 days	4 years 1 month 6 days
Finite-Lived Intangible Assets, Net [Abstract]
Gross	$ 21.8	$ 21.6
Accumulated Amortization	19.6	16.1
Total	$ 2.2	$ 5.5