Balance Sheet Account Detail (Goodwill and Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Goodwill, Finite-lived, and Indefinite-lived Intangible Assets [Line Items]
Goodwill	$ 120,977	$ 120,927
Total	65,472
Intangible assets (excluding goodwill), net	79,380	80,403
Developed technology
Goodwill, Finite-lived, and Indefinite-lived Intangible Assets [Line Items]
Finite lived intangibles	67,600	67,600
Accumulated amortization	(8,003)	(7,167)
Total	59,597	60,433
Customer relationships
Goodwill, Finite-lived, and Indefinite-lived Intangible Assets [Line Items]
Finite lived intangibles	7,500	7,500
Accumulated amortization	(1,625)	(1,438)
Total	5,875	6,062
Trademarks and trade names
Goodwill, Finite-lived, and Indefinite-lived Intangible Assets [Line Items]
Indefinite lived intangibles	2,708	2,708
In-process research and development
Goodwill, Finite-lived, and Indefinite-lived Intangible Assets [Line Items]
Indefinite lived intangibles	$ 11,200	$ 11,200