Segments and Geographic Information - Schedule of Other Information by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Product revenues	$ 6,635	$ 3,508	$ 11,510	$ 6,802
Service revenues	2,714	2,110	5,174	4,588
Royalties	864	1,036	1,855	1,399
Other revenues		0		0
Total revenues	10,213	6,654	18,539	13,670
Cost of product revenues	3,521	1,953	6,633	4,379
Cost of service revenues	2,049	1,916	3,815	3,762
Total cost of revenues	5,570	3,869	10,448	8,141
Gross profit	4,643	2,785	8,091	5,529
Total operating expenses	4,976	2,706	9,255	5,558
Total non-operating income	10	77	154	349
Income (loss) before income taxes	(323)	156	(1,010)	320
Product [Member]
Revenues
Product revenues	6,635	3,508	11,510	6,969
Royalties	864	1,036	1,855	2,113
Other revenues		0		0
Total revenues	7,499	4,544	13,365	9,082
Cost of product revenues	3,521	1,953	6,633	4,379
Total cost of revenues	3,521	1,953	6,633	4,379
Gross profit	3,978	2,591	6,732	4,703
Service [Member]
Revenues
Service revenues	2,714	2,110	5,174	4,588
Other revenues		0		0
Total revenues	2,714	2,110	5,174	4,588
Cost of service revenues	2,049	1,916	3,815	3,762
Total cost of revenues	2,049	1,916	3,815	3,762
Gross profit	$ 665	$ 194	$ 1,359	$ 826