Goodwill and Intangible Assets, Net (Summary of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Write-off related to discontinued project	$ 0	$ 4,754	$ 0
Accumulated amortization	(102,488)	(95,402)
Net carrying amount of finite-lived intangible assets	41,707
Intangible assets, gross	148,178	151,829
Intangible assets, net	$ 45,690	56,427
Weighted average remaining useful life of intangible assets	6 years 6 months 20 days
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of finite-lived intangible assets	$ 138,857	143,275
Accumulated amortization	(97,900)	(90,219)
Net carrying amount of finite-lived intangible assets	40,957	53,056
Patents, copyrights, and trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of finite-lived intangible assets	5,338	5,636
Accumulated amortization	(4,588)	(4,969)
Net carrying amount of finite-lived intangible assets	750	667
Other
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of finite-lived intangible assets	0	214
Accumulated amortization	0	(214)
Net carrying amount of finite-lived intangible assets	0	0
In progress
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	3,906	2,378
Trademarks and other
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 77	$ 326
Minimum | Capitalized software
Finite-Lived Intangible Assets [Line Items]
Useful life	2 years
Maximum | Capitalized software
Finite-Lived Intangible Assets [Line Items]
Useful life	8 years