Mergers and Acquisitions (Details) (USD $)	9 Months Ended			0 Months Ended		3 Months Ended		9 Months Ended		0 Months Ended					3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Mar. 28, 2014 FFHI Preferred Stock	Jul. 26, 2013 FFHI	Sep. 30, 2014 FFHI	Sep. 30, 2013 FFHI	Sep. 30, 2014 FFHI	Sep. 30, 2013 FFHI	Jul. 26, 2013 FFHI Common Stock	Jul. 26, 2013 FFHI FFHI Preferred Stock	Jul. 26, 2013 FFHI As previously recorded by acquiree	Jul. 26, 2013 FFHI Initial Fair Value Adjustments	Jul. 26, 2013 FFHI Subsequent Fair Value Adjustments	Sep. 30, 2013 Savannah	Sep. 30, 2013 Savannah
Mergers and Acquisitions
Fixed exchange ratio for shares issued										0.4237	1
Assets
Cash and cash equivalents					$ 174,082,000							$ 174,082,000
Investment securities					311,812,000							313,200,000	(1,388,000)
Loans held for sale					19,864,000							19,858,000	6,000
Loans					2,275,682,000							2,355,527,000	(92,720,000)	12,875,000
Premises and equipment					76,367,000							82,399,000	(5,435,000)	(597,000)
Intangible assets					38,233,000							7,037,000	33,738,000	(2,542,000)
Mortgage servicing rights					19,156,000							19,156,000
Other real estate owned					13,178,000							13,271,000	(2,065,000)	1,972,000
FDIC receivable for loss sharing agreement					21,713,000							47,459,000	(18,122,000)	(7,624,000)
Bank owned life insurance	98,505,000	96,058,000	97,197,000		51,020,000							51,513,000		(493,000)
Deferred tax asset					32,877,000							(5,279,000)	42,741,000	(4,585,000)
Other assets					45,380,000							47,257,000	(6,125,000)	4,248,000
Total assets					3,079,364,000							3,125,480,000	(49,370,000)	3,254,000
Deposits:
Noninterest-bearing					430,517,000							430,517,000
Interest-bearing					2,091,296,000							2,083,495,000	7,801,000
Total deposits					2,521,813,000							2,514,012,000	7,801,000
Other borrowings					301,713,000							280,187,000	21,526,000
Other liabilities					23,280,000							25,584,000	(2,059,000)	(245,000)
Total liabilities					2,846,806,000							2,819,783,000	27,268,000	(245,000)
Net identifiable assets acquired over (under) liabilities assumed					232,558,000							305,697,000	(76,638,000)	3,499,000
Goodwill	317,700,000				214,395,000								217,894,000	(3,499,000)
Net assets acquired over liabilities assumed					446,953,000							305,697,000	141,256,000
Consideration:
Common shares issued					7,018,274					7,018,274
Purchase price per share of the Company's common stock (in dollars per share)					$ 54.34
Company common stock issued and cash exchanged for fractional shares					381,423,000
Cash paid for stock options outstanding					530,000
Assumption of preferred stock					65,000,000
Fair value of total consideration transferred					446,953,000
Redemption of preferred stock (in shares)				65,000
Liquidation preference (per share)				1,000
Annual dividend rate (as a percent)	9.00%	5.00%		9.00%
Merger-related expense						6,800,000		19,300,000							35,000	2,900,000
Proforma amounts
Total revenues (net interest income plus noninterest income), Pro Forma						104,822,000	107,069,000	314,206,000	329,046,000
Net operating income available to common shareholders, Pro Forma						$ 24,108,000	$ 19,092,000	$ 66,098,000	$ 58,163,000