Certain Transfers of Financial Assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Servicing Assets at Fair Value [Line Items]      
Servicing rights $ 64,897 $ 53,202  
Residential mortgage      
Servicing Assets at Fair Value [Line Items]      
Servicing rights 56,720 46,785 23,085
SBA servicing rights      
Servicing Assets at Fair Value [Line Items]      
Servicing rights 4,872 4,529  
Indirect automobile loan servicing rights      
Servicing Assets at Fair Value [Line Items]      
Servicing rights $ 3,305 $ 1,888