Revenue Recognition - Disaggregated Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	$ 14,180	$ 19,203	$ 29,276	$ 39,881
Software [Member] | Third Party Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	11,684	16,992	24,785	33,056
Software [Member] | Proprietary Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	258	281	509	2,076
Professional Engineering Service [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	2,238	1,930	3,982	4,749
North America [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	12,039	18,179	26,567	37,468
North America [Member] | Software [Member] | Third Party Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	9,785	16,281	22,512	31,400
North America [Member] | Software [Member] | Proprietary Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	240	265	484	1,948
North America [Member] | Professional Engineering Service [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	2,014	1,633	3,571	4,120
Europe [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	698	889	1,159	1,828
Europe [Member] | Software [Member] | Third Party Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	520	702	840	1,295
Europe [Member] | Software [Member] | Proprietary Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	10	5	16	105
Europe [Member] | Professional Engineering Service [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	168	182	303	428
Asia [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	1,443	135	1,550	585
Asia [Member] | Software [Member] | Third Party Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	1,379	9	1,433	361
Asia [Member] | Software [Member] | Proprietary Software [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	8	11	9	23
Asia [Member] | Professional Engineering Service [Member]
Disaggregation Of Revenue [Line Items]
Disaggregated revenue	$ 56	$ 115	$ 108	$ 201