FAIR VALUE OF FINANCIAL INSTRUMENTS - Recurring basis (Details) - Other Long Term Liabilities [Member] - USD ($) |
Sep. 30, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Liabilities | ||
| Deferred Compensation | $ 31,150,000 | $ 30,928,000 |
| Cash flow hedges designated as qualifying instruments | (784,000) | |
| Fair Value, Inputs, Level 1 [Member] | ||
| Liabilities | ||
| Deferred Compensation | 23,746,000 | 23,476,000 |
| Cash flow hedges designated as qualifying instruments | 0 | |
| Fair Value, Inputs, Level 2 [Member] | ||
| Liabilities | ||
| Deferred Compensation | 0 | 0 |
| Cash flow hedges designated as qualifying instruments | (784,000) | |
| Fair Value, Inputs, Level 3 [Member] | ||
| Liabilities | ||
| Deferred Compensation | 0 | 0 |
| Cash flow hedges designated as qualifying instruments | 0 | |
| Measured at Net Asset Value as Practical Expedient [Member] | ||
| Liabilities | ||
| Deferred Compensation | 7,404,000 | $ 7,452,000 |
| Cash flow hedges designated as qualifying instruments | $ 0 |