Variable Interest Entities - Carrying Amount and Maximum Exposure to Loss Relating to VIEs (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2014
Dec. 31, 2013
Variable Interest Entity [Line Items]    
Carrying Amount $ 38,252 $ 41,526
Maximum Exposure to Loss 78,760 83,728
Real Estate Joint Ventures
   
Variable Interest Entity [Line Items]    
Carrying Amount 21,454 22,104
Maximum Exposure to Loss 21,454 22,104
Affordable Housing Real Estate Joint Ventures
   
Variable Interest Entity [Line Items]    
Carrying Amount 16,798 19,422
Maximum Exposure to Loss $ 57,306 $ 61,624