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, 2011	$ 381,780		$ 35,099	$ 233,232	$ 116,198	$ (2,749)
Balance (in shares) at Dec. 31, 2011			14,039,422
Comprehensive income (loss):
Net income	24,121				24,122		24,122
Other comprehensive loss, net of tax	2,521					2,521	2,521
Comprehensive income	26,643						26,643
Cash dividends declared at $.55 and $.51 per share for the period ended 30th September, 2013 and 2012 respectively	(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 in Peoples Bancorporation acquisition	31,145		2,507	28,638
Common stock issued in Peoples Bancorporation acquisition (in shares)			1,002,741
Balance at Sep. 30, 2012	433,924		37,785	263,569	132,798	(228)
Balance (in shares) at Sep. 30, 2012	15,114,185		15,114,185
Balance at Dec. 31, 2012	507,549		42,344	328,843	135,986	376
Balance (in shares) at Dec. 31, 2012	16,937,464		16,937,464
Comprehensive income (loss):
Net income	35,235				35,235		35,235
Other comprehensive loss, net of tax	(11,004)					(11,004)	(11,004)
Comprehensive income	24,231						24,231
Cash dividends on Series A preferred stock at annual dividend rate of 5%	(542)				(542)
Cash dividends declared at $.55 and $.51 per share for the period ended 30th September, 2013 and 2012 respectively	(10,699)				(10,699)
Employee stock purchases	402		23	379
Employee stock purchases (in shares)			9,385
Stock options exercised	1,054		92	962
Stock options exercised (in shares)			37,021
Restricted stock awards			194	(194)
Restricted stock awards (in shares)			77,354
Common stock repurchased	(673)		(32)	(641)
Common stock repurchased (in shares)			(12,953)
Share-based compensation expense	2,332			2,332
Common stock issued for First Financial Holdings, Inc. acquisition	381,372		17,545	363,827
Common stock issued for First Financial Holdings, Inc. acquisition (shares)			7,018,274
Preferred stock assumed in First Financial Holdings, Inc. acquisition	65,000	1		64,999
Preferred stock assumed in First Financial Holdings, Inc. acquisition (shares)		65,000
Balance at Sep. 30, 2013	$ 970,026	$ 1	$ 60,166	$ 760,507	$ 159,980	$ (10,628)
Balance (in shares) at Sep. 30, 2013	24,066,545	65,000	24,066,545