Summary of Significant Accounting Policies and Basis of Presentation - Software Development Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Research and development costs from continuing operations, including the amortization of amounts previously capitalized	$ 8.3	$ 1.2	$ 1.6
Software Developed for Internal Use | Minimum
Finite-Lived Intangible Assets [Line Items]
Expected useful life	3 years
Software Developed for Internal Use | Maximum
Finite-Lived Intangible Assets [Line Items]
Expected useful life	7 years
Software Development
Finite-Lived Intangible Assets [Line Items]
Expected useful life	3 years