Intangible Assets - Summary of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,395	$ 1,218
Accumulated Amortization	(790)	(744)
Net Carrying Amount End of Period	605	474
Core Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Average Remaining Amortization Period	1 year 5 months 12 days	1 year 8 months 12 days
Cost	978	978
Accumulated Amortization	(734)	(691)
Net Carrying Amount End of Period	244	287
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Average Remaining Amortization Period	2 years 5 months 12 days	2 years 8 months 12 days
Cost	89	89
Accumulated Amortization	(56)	(53)
Net Carrying Amount End of Period	33	36
Royalty License [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	328	151
Net Carrying Amount End of Period	$ 328	$ 151