Consolidated Statements of Changes in Stockholders Equity (Unaudited) (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Common stock transactions:
Common shares purchased and retired, shares	14,464	246,596
Common shares issued, shares	15,440	11,506,503
Non-vested common shares issued, shares	130,904	117,140
Non-vested common shares forfeited, shares	20,039	14,724
Stock options exercised, shares	67,197	86,129
Shares tendered in payment of option price and income tax withholding amounts, shares	114,211	69,363
Cash dividends declared:
Common	$ 0.3375	$ 0.3375
Preferred	6.75%	6.75%
Common stock
Common stock transactions:
Common shares purchased and retired, shares	14,464	246,596
Common shares issued, shares	15,440	11,506,503
Non-vested common shares issued, shares	130,904	117,140
Non-vested common shares forfeited, shares	20,039	14,724
Stock options exercised, shares	67,197	86,129
Shares tendered in payment of option price and income tax withholding amounts, shares	114,211	69,363
Retained earnings
Cash dividends declared:
Common	$ 0.3375	$ 0.3375
Preferred	6.75%	6.75%