Software and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Software, net	$ 246,314		$ 246,314		$ 137,228
Software, accumulated amortization	275,600		275,600		252,200
Other intangible assets amortization expense	7,600	$ 4,800	13,100	$ 9,700
Software for Resale
Finite-Lived Intangible Assets [Line Items]
Software, net	21,500		21,500		27,500
Software, amortization expense	3,000	3,400	6,000	7,000
Software for Internal Use
Finite-Lived Intangible Assets [Line Items]
Software, net	224,800		224,800		$ 109,700
Software, amortization expense	$ 13,300	$ 10,300	$ 23,700	$ 20,800
Minimum | Software for Resale
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (in years)			3 years
Minimum | Software for Internal Use
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (in years)			3 years
Maximum | Software for Resale
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (in years)			10 years
Maximum | Software for Internal Use
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (in years)			10 years