Loans - Schedule of Carrying Amount of Loans Acquired (Detail) - Florida Bank Group, Inc., Old Florida Bancshares, Inc., Georgia Commerce Bancshares, Inc. - Receivables Acquired With Deteriorated Credit Quality $ in Thousands	Sep. 30, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable
Contractually required principal and interest at acquisition	$ 53,532
Non-accretable difference (expected losses and foregone interest)	(7,852)
Cash flows expected to be collected at acquisition	45,680
Accretable yield	(4,592)
Basis in acquired loans at acquisition	41,088
Acquired Impaired Loans
Accounts, Notes, Loans and Financing Receivable
Contractually required principal and interest at acquisition	53,532
Non-accretable difference (expected losses and foregone interest)	(7,852)
Cash flows expected to be collected at acquisition	45,680
Accretable yield	(4,592)
Basis in acquired loans at acquisition	41,088
Acquired Performing Impaired Loans
Accounts, Notes, Loans and Financing Receivable
Contractually required principal and interest at acquisition	0
Non-accretable difference (expected losses and foregone interest)	0
Cash flows expected to be collected at acquisition	0
Accretable yield	0
Basis in acquired loans at acquisition	$ 0