SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Prior Period Balance Sheet Adjustments, Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, net	$ 16,798	$ 6,528
Prepaid expenses and other current assets	7,758	8,715
DEFERRED TAX ASSETS	2,364	11,342
Deferred income on sales to distributors		0
Other accrued liabilities	4,009	2,734
Retained earnings	$ 351,408	332,891
As Reported
Accounts receivable, net		6,961
Prepaid expenses and other current assets		8,520
DEFERRED TAX ASSETS		12,032
Deferred income on sales to distributors		16,207
Other accrued liabilities		2,434
Retained earnings		317,912
Adjustments for Accounting Standards Update 2014-09 [Member]
Accounts receivable, net		(433)
Prepaid expenses and other current assets		195
DEFERRED TAX ASSETS		(690)
Deferred income on sales to distributors		(16,207)
Other accrued liabilities		300
Retained earnings		$ 14,979