CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Cash dividends declared (in dollars per share)	$ 0.25	$ 0.25
Distribution of shares of treasury stock for directors' compensation (in shares)	10,238	10,378
Distribution of shares of treasury stock for employee compensation (in shares)	3,453	2,392
Distribution of shares of treasury stock for directors' deferred compensation (in shares)		286
Distribution of shares of treasury stock granted for employee restricted stock awards (in shares)	1,079	2,300
Purchase of shares of treasury stock (in shares)	8,654