Loans and the Allowance for Loan Losses - (Details 9) - Receivables Acquired with Deteriorated Credit Quality - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014	Sep. 01, 2013
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		$ 329,922	$ 344,425
Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		20,993	8,004
Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		50,869	135,037
Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		258,060	$ 201,384
Contractually-required principal and interest
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		474,115
Contractually-required principal and interest | Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		22,400
Contractually-required principal and interest | Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		67,828
Contractually-required principal and interest | Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		383,887
Nonaccretable difference
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[1]	(100,271)
Nonaccretable difference | Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[1]	(1,397)
Nonaccretable difference | Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[1]	(11,983)
Nonaccretable difference | Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[1]	(86,891)
Cash flows expected to be collected
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		373,844
Cash flows expected to be collected | Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		21,003
Cash flows expected to be collected | Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		55,845
Cash flows expected to be collected | Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality		296,996
Accretable yield
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[2]	(43,922)
Accretable yield | Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[2]	(10)
Accretable yield | Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[2]	(4,976)
Accretable yield | Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality	[2]	$ (38,936)
Heritage Financial Group
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality				$ 1,111,617
Heritage Financial Group | Contractually-required principal and interest
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality				1,237,944
Heritage Financial Group | Nonaccretable difference
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality				59,408
Heritage Financial Group | Cash flows expected to be collected
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality				1,178,536
Heritage Financial Group | Accretable yield
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Acquired with deteriorated credit quality				$ 66,919

[1] Represents contractual principal and interest cash flows of $100,023 and $249, respectively, not expected to be collected.

[2] Represents contractual interest payments of $2,329 expected to be collected and purchase discount of $41,594.