FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Notes Payable	$ 101,587	$ 95,950
Financial Liabilities:
Convertible Debt, Fair Value Disclosures	83,400
Fair Value, Measurements, Recurring [Member]
Financial Assets:
Deferred compensation assets	2,035	3,617
Financial Liabilities:
Foreign currency contracts		14
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Deferred compensation assets	493	572
Financial Liabilities:
Foreign currency contracts		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Deferred compensation assets	1,542	3,045
Financial Liabilities:
Foreign currency contracts		14
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Deferred compensation assets	0	0
Financial Liabilities:
Foreign currency contracts		0
Acquired Individual Deferred Compensation Arrangement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Plan Assets	$ 1,500	$ 3,000