Derivatives and Hedging Activities Cash Flow Hedges Text Description (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012 Years percent	Sep. 30, 2011	Sep. 30, 2012 Years percent	Sep. 30, 2011	Dec. 31, 2011 Designated as Hedging Instrument [Member] Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Collateral, Right to Reclaim Cash					$ 8,000,000
Derivative Asset, Notional Amount	75,000,000		75,000,000
Derivative Contract Term	5		5
Derivative, Description of Hedged Item			6.25%
Derivative, Description of Variable Rate Basis			three-month LIBOR plus 1.68%
Derivative, Average Variable Interest Rate	4.45%		4.45%
Loss on Cash Flow Hedge Ineffectiveness	0	0	0	0
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 1,800,000		$ 1,800,000