Supplementary Financial Statement Information - Intangibles (Details6a) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 59.6	$ 55.9
Finite-Lived Intangible Assets, Accumulated Amortization	(21.7)	(12.0)
Finite-Lived Intangible Assets, Net	37.9	43.9
Amortization of Intangible Assets	9.7	9.0	$ 4.0
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	10.6
Finite-Lived Intangible Assets, Amortization Expense, Year Two	8.4
Finite-Lived Intangible Assets, Amortization Expense, Year Three	8.4
Finite-Lived Intangible Assets, Amortization Expense, Year Four	7.1
Finite-Lived Intangible Assets, Amortization Expense, Year Five	3.4
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	36.6	36.6
Finite-Lived Intangible Assets, Accumulated Amortization	(12.5)	(7.4)
Finite-Lived Intangible Assets, Net	$ 24.1	29.2
Finite-Lived Intangible Assets, Remaining Amortization Period	4 years 7 months 6 days
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 23.0	19.3
Finite-Lived Intangible Assets, Accumulated Amortization	(9.2)	(4.6)
Finite-Lived Intangible Assets, Net	$ 13.8	$ 14.7
Finite-Lived Intangible Assets, Remaining Amortization Period	3 years 7 months 6 days