Derivative Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within 12 months	$ 447,000
Remaining unamortized deferred gain (loss) balance of all previously terminated cash flow hedges	(1,600,000)	(2,000,000)
Remaining deferred (gain) loss balance on all previously terminated fair value hedges	10,700,000	13,900,000
Deferred gain balance on terminated fair value hedges expected to be reclassified from long-term debt	3,100,000
Collateral pledge to collateralize derivative liabilities	72,200,000
Deferred gains of hedges reclassified into earnings	3,200,000	7,300,000	6,900,000
Federal Funds Sold, Counterparty with CCC [Member]
Derivative [Line Items]
Collateral pledge to collateralize derivative liabilities	3,100,000
Fixed Rate Residential Mortgage [Member]
Derivative [Line Items]
Commitments to fund fixed-rate mortgage loans	65,000,000	158,000,000
Unrealized gain on fair value of fixed-rate mortgage loans to customers	(2,200,000)	900,000
Sale of outstanding commitments	92,000,000	231,500,000
Unrealized loss on mortgage loans	1,400,000
Interest Rate Swap [Member] | Customer Position [Member]
Derivative [Line Items]
Notional amount of interest rate swap contracts	$ 1,180,000,000	$ 45,400,000