Goodwill, Purchased Intangibles, and Software Development Costs - Summary of Amortization Expenses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of purchased intangibles in revenues	$ 19	$ 19	$ 57	$ 56
Amortization of purchased intangibles in cost of product revenues	732	1,248	2,304	3,744
Amortization of purchased intangibles	2,435	2,487	7,363	7,535
Total amortization expenses of purchased intangibles	$ 3,186	$ 3,754	$ 9,724	$ 11,335