Goodwill, Purchased Intangibles, and Software Development Costs - Summary of Amortization Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of purchased intangibles in revenues	$ 51	$ 75	$ 75
Amortization of purchased intangibles in cost of product revenues	956	3,035	9,361
Amortization of purchased intangibles in operating expenses	9,495	9,781	10,389
Total amortization expenses of purchased intangibles	$ 10,502	$ 12,891	$ 19,825