Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Revenue from Contract with Customer, Including Assessed Tax	$ 20,213	$ 26,517	$ 66,069	$ 75,094
Costs of Design-to-silicon-yield solutions:
Gross profit	9,530	14,086	32,987	39,854
Operating expenses:
Research and development	6,755	7,875	21,100	22,432
Selling, general and administrative	5,507	5,680	17,801	17,775
Amortization of other acquired intangible assets	108	107	326	291
Total operating expenses	12,370	13,662	39,227	40,498
Income (loss) from operations	(2,840)	424	(6,240)	(644)
Interest and other income (expense), net	223	(104)	283	(305)
Income (loss) before income taxes	(2,617)	320	(5,957)	(949)
Income tax benefit	(535)	(270)	(1,355)	(2,246)
Net income (loss)	$ (2,082)	$ 590	$ (4,602)	$ 1,297
Net income (loss) per share:
Basic (in dollars per share)	$ (0.06)	$ 0.02	$ (0.14)	$ 0.04
Diluted (in dollars per share)	$ (0.06)	$ 0.02	$ (0.14)	$ 0.04
Weighted average common shares:
Basic (in shares)	32,184	32,078	32,105	32,060
Diluted (in shares)	32,184	32,969	32,105	33,317
Net income (loss)	$ (2,082)	$ 590	$ (4,602)	$ 1,297
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	(168)	409	(414)	1,117
Comprehensive income (loss)	(2,250)	999	(5,016)	2,414
License and Service [Member]
Revenues:
Revenue from Contract with Customer, Including Assessed Tax	13,976	19,229	47,431	55,426
Costs of Design-to-silicon-yield solutions:
Direct costs of Design-to-silicon-yield solutions	10,539	12,295	32,651	34,913
Amortization of acquired technology	144	136	431	327
Total cost of Design-to-silicon-yield solutions	10,683	12,431	33,082	35,240
Gainshare Performance Incentives [Member]
Revenues:
Revenue from Contract with Customer, Including Assessed Tax	$ 6,237	$ 7,288	$ 18,638	$ 19,668