Mergers and Acquisitions (Details) (USD $) In Thousands, except Share data, unless otherwise specified				0 Months Ended		0 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Feb. 19, 2013 First Financial Holdings, Inc. ("First Financial")	Mar. 31, 2013 First Financial Holdings, Inc. ("First Financial") item	Feb. 19, 2013 First Financial Holdings, Inc. ("First Financial") Common Stock	Feb. 19, 2013 First Financial Holdings, Inc. ("First Financial") Preferred Stock
Mergers and Acquisitions
Total assets	$ 5,141,929	$ 5,136,313	$ 4,046,343		$ 3,200,000
Loans	3,526,607	3,569,235	2,724,496		2,400,000
Deposits	$ 4,219,356	$ 4,298,360	$ 3,356,637		$ 2,600,000
Number of branches					66
Aggregate consideration (in shares)				7,002,384
Fixed exchange ratio (as a percent)						0.4237	1