FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Carrying Value
Fair value disclosure
Debt obligations	$ 236,882	$ 211,703
Fair Value
Fair value disclosure
Debt obligations	236,822	211,495
Credit Facility | Carrying Value
Fair value disclosure
Debt obligations	70,000	70,000
Credit Facility | Fair Value
Fair value disclosure
Debt obligations	70,000	70,000
Accounts receivable securitization program | Carrying Value
Fair value disclosure
Debt obligations	35,000	35,000
Accounts receivable securitization program | Fair Value
Fair value disclosure
Debt obligations	35,000	35,000
Notes payable | Carrying Value
Fair value disclosure
Debt obligations	131,882	106,703
Notes payable | Fair Value
Fair value disclosure
Debt obligations	$ 131,822	$ 106,495