FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Jun. 15, 2015
Fair Value, Measurements, Recurring [Member]
Financial Assets:
Deferred compensation assets	$ 2,651	$ 3,617
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Deferred compensation assets	481	572
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Deferred compensation assets	2,170	3,045
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Deferred compensation assets	0	$ 0
Convertible Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Notes Payable, Noncurrent	125,000		$ 125,000
Liabilities:
Convertible Notes, Carrying Value	97,309		$ 96,700
Convertible Notes, Fair Value Disclosure	$ 82,500