NET INCOME PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
[1],[2] | Sep. 30, 2017 |
[2],[3] | Jun. 30, 2017 |
[2],[4] | Mar. 31, 2017 |
[2] | Dec. 31, 2016 |
[2] | Sep. 30, 2016 |
[2] | Jun. 30, 2016 |
[2] | Mar. 31, 2016 |
[2] | Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|||||||||||
NET INCOME PER COMMON SHARE [Abstract] | |||||||||||||||||||||||||||||
Net income | $ 18,009 | $ 19,428 | $ 18,598 | ||||||||||||||||||||||||||
Basic earnings per common share [Abstract] | |||||||||||||||||||||||||||||
Weighted average shares outstanding (in shares) | 24,294,000 | 24,284,000 | 24,370,000 | ||||||||||||||||||||||||||
Per share amount (in dollars per share) | $ 0.58 | $ 0.07 | $ 0.03 | $ 0.06 | $ (0.03) | $ 0.12 | $ 0.42 | $ 0.30 | $ 0.74 | [2] | $ 0.80 | [2] | $ 0.76 | ||||||||||||||||
Diluted earnings per common share [Abstract] | |||||||||||||||||||||||||||||
Weighted average shares outstanding (in shares) | 25,129,000 | 24,982,000 | 25,181,000 | ||||||||||||||||||||||||||
Per share amount (in dollars per share) | $ 0.56 | $ 0.07 | $ 0.03 | $ 0.06 | $ (0.03) | $ 0.11 | $ 0.41 | $ 0.29 | $ 0.72 | [2] | $ 0.78 | [2] | $ 0.74 | ||||||||||||||||
Weighted average shares-denominator basic computation (in shares) | 24,294,000 | 24,284,000 | 24,370,000 | ||||||||||||||||||||||||||
Unvested restricted stock unit grant (in shares) | 367,000 | 310,000 | 141,000 | ||||||||||||||||||||||||||
Effect of dilutive stock options (in shares) | 468,000 | 388,000 | 670,000 | ||||||||||||||||||||||||||
Weighted average shares, as adjusted denominator diluted computation (in shares) | 25,129,000 | 24,982,000 | 25,181,000 | ||||||||||||||||||||||||||
Potential common stock shares issuable upon exercise of options (in shares) | 1,323,587 | 1,348,437 | 1,376,437 | ||||||||||||||||||||||||||
|