INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax [Line Items]
Change in effective income tax rate during the period	(71.20%)
Effective income tax rate reconciliation, share-based compensation, excess tax benefit, amount	$ 3,800
Amount of unrecorded benefit expected to be recognized	700
Effective income tax rate reconciliation, foreign income tax rate differential, increase (decrease), amount	$ 800	$ (2,300)	$ (1,200)
Effective foreign income tax rate	12.70%	10.60%	4.90%
Change in effective foreign income tax rate during period	2.10%	(5.70%)	(39.60%)
Undistributed earnings of foreign subsidiaries	$ 301,300
Estimated tax liability on undistributed earnings of foreign subsidiaries	42,500
Operating loss carryforwards, not subject to expiration	21,700
Less valuation allowance	3,604	$ 4,887	$ 6,800
Deferred tax assets, gross	79,230	82,481	91,100
Valuation allowances and reserves, period increase (decrease)	(1,300)	$ (1,900)
Unrecognized tax benefits that would impact effective tax rate	800
Benefit for income tax penalties and interest expense			200
Penalties and interest accrued			$ 100
Accounting Standards Update 2016-09
Income Tax [Line Items]
Effective income tax rate reconciliation, share-based compensation, excess tax benefit, amount	1,400
Tax benefit, Federal research credit study	500
Internal Revenue Service (IRS)
Income Tax [Line Items]
Operating loss carryforwards	28,500
Foreign Tax Authority
Income Tax [Line Items]
Operating loss carryforwards	24,200
Operating loss carryforwards, subject to expiration	2,500
State and Local Jurisdiction
Income Tax [Line Items]
Operating loss carryforwards	$ 14,000