Loans and the Allowance for Loan Losses (Details 9) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	$ 400,985		$ 448,930
Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	20,299		24,519
Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	146,830		157,155
Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	233,856		267,256
Contractually-required principal and interest
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	558,168
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
Loans acquired with deteriorated credit quality	57,279
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
Loans acquired with deteriorated credit quality	183,328
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
Loans acquired with deteriorated credit quality	317,561
Nonaccretable Difference
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(120,809)	[1]
Nonaccretable Difference | Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(36,979)	[1]
Nonaccretable Difference | Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(33,251)	[1]
Nonaccretable Difference | Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(50,579)	[1]
Cash flows expected to be collected
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	437,359
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
Loans acquired with deteriorated credit quality	20,300
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
Loans acquired with deteriorated credit quality	150,077
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
Loans acquired with deteriorated credit quality	266,982
Accretable Yield
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(36,374)	[2]
Accretable Yield | Impaired Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(1)	[2]
Accretable Yield | Other Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	(3,247)	[2]
Accretable Yield | Not Covered Loans
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	$ (33,126)	[2]

[1] Represents contractual principal and interest cash flows of $112,523 and $8,286, respectively, not expected to be collected.

[2] Represents contractual interest payments of $3,387 expected to be collected and purchase discount of $32,987.