FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Liabilities:
Convertible Notes, Carrying Value	$ 103,045	$ 101,587
Fair Value, Measurements, Recurring [Member]
Financial Assets:
Deferred compensation assets	1,948	2,035
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Deferred compensation assets	438	493
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Deferred compensation assets	1,510	1,542
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Deferred compensation assets	0	$ 0
Convertible Debt [Member]
Liabilities:
Convertible Notes, Fair Value Disclosure	$ 88,700