Cash and Due from Banks (Details) (USD $)
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Cash and Due from Banks [Abstract]      
Cash and due from banks $ 522,358,000 $ 634,432,000 $ 309,240,000
Non-interest bearing deposits with other banks 63,000,000 36,700,000  
Interest bearing balances with the Federal Reserve 426,300,000 560,500,000  
Interest bearing balances with the Federal Home Loan Bank 5,000,000 3,600,000  
Minimum required bank deposits with other or federal reserve bank $ 66,100,000 $ 152,300,000