Assets Acquired in FDIC-Assisted Acquisitions - Schedule of Acquisition Details (Detail)	3 Months Ended	34 Months Ended
	Jun. 30, 2014	Jul. 31, 2012 Entity
American United Bank (AUB) [Member]
Business Acquisition [Line Items]
Bank Acquired	American United Bank ("AUB")
Branches		1
Date Acquired		Oct. 23, 2009
United Security Bank (USB) [Member]
Business Acquisition [Line Items]
Bank Acquired	United Security Bank ("USB")
Branches		2
Date Acquired		Nov. 06, 2009
Satilla Community Bank (SCB) [Member]
Business Acquisition [Line Items]
Bank Acquired	Satilla Community Bank ("SCB")
Branches		1
Date Acquired		May 14, 2010
First Bank of Jacksonville (FBJ) [Member]
Business Acquisition [Line Items]
Bank Acquired	First Bank of Jacksonville ("FBJ")
Branches		2
Date Acquired		Oct. 22, 2010
Tifton Banking Company (TBC) [Member]
Business Acquisition [Line Items]
Bank Acquired	Tifton Banking Company ("TBC")
Branches		1
Date Acquired		Nov. 12, 2010
Darby Bank & Trust (DBT) [Member]
Business Acquisition [Line Items]
Bank Acquired	Darby Bank & Trust ("DBT")
Branches		7
Date Acquired		Nov. 12, 2010
High Trust Bank (HTB) [Member]
Business Acquisition [Line Items]
Bank Acquired	High Trust Bank ("HTB")
Branches		2
Date Acquired		Jul. 15, 2011
One Georgia Bank (OGB) [Member]
Business Acquisition [Line Items]
Bank Acquired	One Georgia Bank ("OGB")
Branches		1
Date Acquired		Jul. 15, 2011
Central Bank of Georgia (CBG) [Member]
Business Acquisition [Line Items]
Bank Acquired	Central Bank of Georgia ("CBG")
Branches		5
Date Acquired		Feb. 24, 2012
Montgomery Bank & Trust (MBT) [Member]
Business Acquisition [Line Items]
Bank Acquired	Montgomery Bank & Trust ("MBT")
Branches		2
Date Acquired		Jul. 06, 2012