Derivatives (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 contracts	Dec. 31, 2012 contracts	Dec. 31, 2011
Credit Derivatives [Line Items]
Counterparty default losses on forward contracts	$ 0	$ 0	$ 0
Commitments and contingent liabilities
Number of interest rate derivatives held	254	164
Notional amount of credit risk derivatives	1,300,000,000	912,000,000
Termination value of derivatives in net liability position	12,100,000	21,800,000
Required collateral posting	13,000,000	0
Minimum collateral posting agreement amount	0	22,500,000
Increase (decrease) in settlement values of the Bank's derivative assets	1,400,000	(45,000)
Interest Rate Forward Sales Commitments [Member]
Credit Derivatives [Line Items]
Commitments and contingent liabilities	152,500,000
Commitments To Originate Loans Held For Sale [Member]
Credit Derivatives [Line Items]
Commitments and contingent liabilities	$ 77,314,000