INCOME TAXES (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Reserves and others	$ 10,869	$ 13,382
Stock-based compensation	19,556	29,402
Contribution carryforward	0	11
Net operating loss carryforward	8,115	64,478
Tax credit carryforward	14,183	17,185
Gross deferred tax assets	52,723	124,458
Valuation allowance	(30,895)	(92,191)
Total deferred tax assets	21,828	32,267
Deferred tax liabilities:
Depreciation and amortization	(12,813)	(30,140)
Disposal of a business unit	(7,152)	0
Total deferred tax liabilities	(19,965)	(30,140)
Net deferred tax assets (liabilities)	$ 1,863	$ 2,127