Information about Geographic Areas and Operating Segments - Profit and Loss Information of Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenue	$ 20,678	$ 22,841
Cost of revenue	15,478	16,588
Gross profit	5,200	6,253
Operating expenses	7,678	6,212
Other income, net	44	55
Income tax benefit		106
Net income (loss)	(2,434)	202
Third Party Software [Member]
Segment Reporting Information [Line Items]
Revenue	16,064	16,797
Cost of revenue	13,354	14,082
Gross profit	2,710	2,715
Proprietary Software [Member]
Segment Reporting Information [Line Items]
Revenue	1,795	2,654
Cost of revenue	41	32
Gross profit	1,754	2,622
Professional Engineering Service [Member]
Segment Reporting Information [Line Items]
Revenue	2,819	3,390
Cost of revenue	2,083	2,474
Gross profit	$ 736	$ 916