Loans and the Allowance for Loan Losses (Details 8) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Fair value of loans determined to be impaired and not to be impaired at the time of acquisition
Loans acquired with deteriorated credit quality	$ 448,930		$ 248,029
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	24,519		31,904
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	157,155		205,184
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	267,256		10,941
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	623,425		386,713
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	67,976		109,054
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	201,215		264,406
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	354,234		13,253
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	(134,545)	[1]	(130,836)	[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	(43,456)	[1]	(77,137)	[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	(40,301)	[1]	(52,517)	[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	(50,788)	[1]	(1,182)	[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	488,880		255,877
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	24,520		31,917
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	160,914		211,889
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	303,446		12,071
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	(39,950)	[2]	(7,848)	[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]	(13)	[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	(3,759)	[2]	(6,705)	[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	$ (36,190)	[2]	$ (1,130)	[2]

[1] Represents contractual principal cash flows of $125,086 and $120,572, respectively, and interest cash flows of $9,459 and $10,264, respectively, not expected to be collected.

[2] Represents contractual interest payments expected to be collected of $3,936 and $4,945, respectively, and purchase discount of $36,014 and $2,903, respectively.