Condensed Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Preferred Stock	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Comprehensive Income
Balance at Dec. 31, 2010	$ 329,957	$ 0	$ 31,985	$ 198,647	$ 103,117	$ (3,792)
Balance (in shares) at Dec. 31, 2010		0	12,793,823
Comprehensive income:
Net income	17,766				17,766		17,766
Other comprehensive income, net of tax	4,437					4,437	4,437
Total comprehensive income	22,203						22,203
Cash dividends declared at $.51 per share	(7,131)				(7,131)
Employee stock purchases	342		29	313
Employee stock purchases (in shares)			11,673
Stock options exercised	423		60	363
Stock options exercised (in shares)			24,102
Restricted stock awards			136	(136)
Restricted stock awards (in shares)			54,080
Common stock repurchased	(252)		(21)	(231)
Common stock repurchased (in shares)			(8,338)
Share-based compensation expense	1,341			1,341
Common stock issued in private placement offering	34,839		2,822	32,017
Common stock issued in private placement offering (in shares)			1,129,032
Balance at Sep. 30, 2011	381,722	0	35,011	232,314	113,752	645
Balance (in shares) at Sep. 30, 2011	14,004,372	0	14,004,372
Balance at Dec. 31, 2011	381,780	0	35,099	233,232	116,198	(2,749)
Balance (in shares) at Dec. 31, 2011	14,039,422	0	14,039,422
Comprehensive income:
Net income	24,122				24,122		24,122
Other comprehensive income, net of tax	2,521					2,521	2,521
Total comprehensive income	26,643						26,643
Cash dividends declared at $.51 per share	(7,522)				(7,522)
Employee stock purchases	361		30	331
Employee stock purchases (in shares)			12,035
Stock options exercised	899		91	808
Stock options exercised (in shares)			36,681
Restricted stock awards			106	(106)
Restricted stock awards (in shares)			42,674
Common stock repurchased	(674)		(48)	(626)
Common stock repurchased (in shares)			(19,368)
Share-based compensation expense	1,292			1,292
Common stock issued for Peoples Bancorporation acquisition	31,145		2,507	28,638
Common stock issued for Peoples Bancorporation acquisition (in shares)			1,002,741
Balance at Sep. 30, 2012	$ 433,924	$ 0	$ 37,785	$ 263,569	$ 132,798	$ (228)
Balance (in shares) at Sep. 30, 2012	15,114,185	0	15,114,185