Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2016
Changes in the carrying amount of goodwill
Balance at the beginning of the period	$ 57,848		$ 58,054	$ 58,054
Currency translation	(4)			(206)
Balance at the end of the period	57,844			57,848
Impairment of goodwill		$ 0
Amortization expense	2,000		$ 2,000
Estimated future amortization expense of purchased intangible assets
2017 (remaining 9 months)	5,622
Developed technology
Changes in the carrying amount of goodwill
Gross Carrying Amount	46,743			46,743
Accumulated Amortization	(41,121)			(39,132)
Net Amount	5,622			7,611
Estimated future amortization expense of purchased intangible assets
Net Amount	$ 5,622			$ 7,611
Developed technology | Minimum
Changes in the carrying amount of goodwill
Useful Lives	5 years			5 years
Developed technology | Maximum
Changes in the carrying amount of goodwill
Useful Lives	6 years			6 years