FINANCIAL MEASUREMENTS AND FINANCIAL INSTRUMENTS - CARRYING VALUE AND FAIR VALUE OF FINANCIAL INSTRUMENTS (Details 3) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Current portion of long-term debt | Carrying Value | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions | ||
| Long-term debt, fair value | $ (20,000) | $ (40,000) |
| Current portion of long-term debt | Fair Value | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions | ||
| Long-term debt, fair value | (20,311) | (39,850) |
| Long-term debt, net of current portion | Carrying Value | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions | ||
| Long-term debt, fair value | (1,582,484) | (1,726,954) |
| Long-term debt, net of current portion | Fair Value | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions | ||
| Long-term debt, fair value | $ (1,657,861) | $ (1,761,601) |