Derivative Instruments (Narrative) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2013
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	(1,200,000)			(1,600,000)
Remaining deferred gain (loss) balance on all previously terminated fair value hedges	8,400,000			10,700,000
Deferred gain balance on terminated fair value hedges expected to be reclassified from long-term debt	3,100,000
Derivative, fair value			4,000,000	2,700,000
Gain (loss) on sale of outstanding commitments	(1,200,000)
Deferred gains (loss) on discontinuation of cash flow hedge reclassified to earnings	2,300,000	2,500,000
Fixed Rate Residential Mortgage [Member]
Derivative [Line Items]
Commitments to fund fixed-rate mortgage loans	78,000,000			65,000,000
Unrealized gain on fair value of fixed-rate mortgage loans to customers	531,000	(682,000)
Sale of outstanding commitments	105,500,000			92,000,000
Interest Rate Swap [Member] | Customer Related Interest Rate Risk [Member]
Derivative [Line Items]
Notional amount of interest rate swap contracts	1,080,000,000			107,800,000
Federal Funds Sold [Member]
Derivative [Line Items]
Federal funds sold	68,100,000
Federal Funds Sold, Counterparty with CCC [Member]
Derivative [Line Items]
Federal funds sold	$ 3,800,000