EARNINGS PER SHARE (EPS) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
EARNINGS PER SHARE (EPS) [Abstract]
Net income	$ 11,529	$ 10,460	$ 23,307	$ 20,494
Less: Dividends paid on earnings allocated to participating securities	(33)	(42)	(73)	(86)
Income attributable to common stock	$ 11,496	$ 10,418	$ 23,234	$ 20,408
Weighted Average Number Of Shares Outstanding Including Participating Securities Basic (in shares)	36,412,733	36,181,381	36,344,359	36,138,178
Less: weighted average participating securities (in shares)	(245,046)	(304,243)	(266,424)	(310,989)
Weighted average shares outstanding utilized in the calculation of basic EPS (in shares)	36,167,687	35,877,138	36,077,935	35,827,189
Earnings Per Share, Basic (in dollars per share)	$ 0.32	$ 0.29	$ 0.65	$ 0.57
Income attributable to common stock	$ 11,496	$ 10,418	$ 23,234	$ 20,408
Weighted average common shares outstanding	36,167,687	35,877,138	36,077,935	35,827,189
Common stock equivalents resulting from the dilutive effect of "in-the-money" stock options	91,690	80,153	80,886	96,160
Weighted average shares outstanding utilized in the calculation of diluted EPS (in shares)	36,259,377	35,957,291	36,158,821	35,923,349
Earnings Per Share, Diluted (in dollars per share)	$ 0.32	$ 0.29	$ 0.64	$ 0.57
Weighted average shares excluded from earnings per share calculation (in shares)	126,453	246,774	136,292	342,056