EARNINGS PER SHARE (Earnings Per Share Computations) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Basic earnings per common share:
Net income	$ 10,588	$ 9,769	$ 9,236	$ 9,246	$ 8,602	$ 9,347	$ 8,819	$ 8,626	$ 38,839	$ 35,394	$ 30,662
Weighted-average common shares outstanding									16,436,131	16,323,870	16,204,952
Basic earnings per common share	$ 0.64	$ 0.59	$ 0.56	$ 0.56	$ 0.53	$ 0.57	$ 0.54	$ 0.53	$ 2.36	$ 2.17	$ 1.89
Diluted earnings per common share:
Net income	$ 10,588	$ 9,769	$ 9,236	$ 9,246	$ 8,602	$ 9,347	$ 8,819	$ 8,626	$ 38,839	$ 35,394	$ 30,662
Weighted-average common shares outstanding for basic earnings per common share									16,436,131	16,323,870	16,204,952
Add: Dilutive effect of assumed exercise of warrant									61,436	38,224	10,370
Add: Dilutive effect of assumed exercises of stock options and awards									136,771	120,843	109,322
Average shares and dilutive potential common shares									16,634,338	16,482,937	16,324,644
Diluted earnings per common share	$ 0.63	$ 0.59	$ 0.56	$ 0.56	$ 0.52	$ 0.57	$ 0.54	$ 0.52	$ 2.33	$ 2.15	$ 1.88