EARNINGS PER SHARE (Computation of Basic and Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Earnings Per Share [Abstract]
Net income	$ 6,366		$ 6,255		$ 18,359		$ 19,250
Dividends and undistributed earnings allocated to participating securities	(20)	[1]	(18)	[1]	(50)	[1]	(48)	[1]
Net income loss available to common shareholders	$ 6,346		$ 6,237		$ 18,309		$ 19,202
Weighted-average common shares outstanding for basic EPS	7,643,720		7,619,411		7,636,352		7,655,619
Dilutive effect of stock-based awards	22,585	[2]	20,023	[2]	15,518	[2]	14,144	[2]
Weighted-average common and potential common shares for diluted EPS	7,666,305		7,639,434		7,651,870		7,669,763
Basic EPS	$ 0.83		$ 0.82		$ 2.40		$ 2.51
Diluted EPS	$ 0.83		$ 0.82		$ 2.39		$ 2.50

[1] Represents dividends paid and undistributed earnings allocated to nonvested restricted stock awards.

[2] Represents the effect of the assumed exercise of stock options, vesting of restricted shares, and vesting of restricted stock units, based on the treasury stock method.