Basis of Presentation and Summary of Significant Accounting Policies - Capitalized Software Costs, Equipment and Leasehold Improvements (Details)	12 Months Ended
	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of acquired equipment	15 years
Equipment
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of acquired equipment	5 years
Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of software	3 years
Estimated useful life of acquired equipment	5 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of software	5 years
Estimated useful life of acquired equipment	30 years