SHAREHOLDERS' EQUITY (Details) - Common Stock - shares |
9 Months Ended | 12 Months Ended | |
|---|---|---|---|
Sep. 30, 2019 |
Dec. 31, 2018 |
Feb. 28, 2015 |
|
| Shareholder's Equity | |||
| Common stock, shares authorized to be repurchased | 20,000,000 | ||
| Remaining shares authorized to be repurchased | 6,820,810 | ||
| Reacquired shares | 1,959,148 | 3,908,041 | |
| Number of shares reacquired through the open market or private purchases | 1,830,584 | 3,706,716 | |
| Number of shares that have been repurchased through the exercise of stock options and vesting of stock awards | 128,564 | 201,325 |