SELECTED QUARTERLY INFORMATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands			3 Months Ended								12 Months Ended
		Jan. 02, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
NET REVENUES			$ 101,108	$ 103,790	$ 97,169	$ 85,326	$ 87,289	$ 88,878	$ 85,265	$ 82,557	$ 387,393	$ 343,989	$ 348,797
Gross Profit			49,384	51,193	47,637	42,947	42,916	44,161	44,018	42,292	191,161	173,387	189,570
Net income			$ 13,617	$ 14,165	$ 11,265	$ 8,843	$ 12,701	$ 11,513	$ 8,590	$ 6,343	$ 47,890	$ 39,147	$ 59,544
Earnings per share
Basic (per share)			$ 0.47	$ 0.49	$ 0.39	$ 0.31	$ 0.45	$ 0.40	$ 0.29	$ 0.22	$ 1.66	$ 1.35	$ 1.99
Diluted (per share)	[1]		$ 0.46	$ 0.48	$ 0.38	$ 0.30	$ 0.44	$ 0.39	$ 0.29	$ 0.21	$ 1.62	$ 1.32	$ 1.93
Shares used in per share calculation
Basic (in shares)			29,196	28,972	28,850	28,679	28,483	28,855	29,368	29,309	28,925	29,001	29,976
Diluted (in shares)	[1]		29,914	29,625	29,422	29,244	29,126	29,298	30,034	30,058	29,619	29,696	30,829
Cambridge Semiconductor Limited [Member]
Business Acquisition [Line Items]
CamSemi Purchase Price		$ 23,300
Payments to Acquire Businesses, Gross		16,700
Consideration applied against outstanding loan		6,600
Business Combination, Accumulated Acquisition Related Costs		$ 1,000	$ 1,000								$ 1,000
Business Combination, Acquisition Related Costs												$ 200	$ 800

[1] The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has excluded all performance-based awards in the 2014 calculation as the performance conditions for those awards were not met as of the end of the period. The Company has included in the 2016 and 2015 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.