Derivatives And Hedging (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013 contracts	Dec. 31, 2012 contracts
Derivative [Line Items]
Accumulated other comprehensive gain (loss) from derivative instruments	$ 861,000	$ (7,489,000)
Interest Rate Contracts [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Number of active interest rate contracts held	3	3
Notional amount of interest rate cash flow hedge derivatives	26,200,000	26,500,000
Derivative, maturity date	Sep. 15, 2017	Sep. 15, 2017
Derivative, lower fixed interest rate range	2.30%	2.30%
Derivative, higher fixed interest rate range	5.00%	5.00%
Cash flow hedge gain (loss) to be amortized within 12 months	(4,100,000)
Interest Rate Contracts [Member] | Fair Value Hedges [Member]
Derivative [Line Items]
Number of active interest rate contracts held	4	4
Notional amount of interest rate fair value hedge derivatives	117,400,000	118,100,000
Derivative, maturity date	Oct. 15, 2017	Oct. 15, 2017
Derivative, lower fixed interest rate range	4.20%	4.20%
Derivative, higher fixed interest rate range	7.50%	7.50%
Derivative, lower variable interest rate range	0.30%	0.30%
Derivative, higher variable interest rate range	4.30%	4.30%
Forward-Starting Contracts [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Number of active interest rate contracts held	3
Notional amount of interest rate cash flow hedge derivatives	$ 150,000,000
Derivative, effective date	Jan. 15, 2014
Derivative, maturity date	Jan. 15, 2024
Derivative, fixed interest rate	2.40%