Derivative Financial Instruments Balance sheet category and fair values of derivative insturments (cash flow hedges) (Details) (Other Liabilities, USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Interest Rate Swap 1
Derivatives, Fair Value [Line Items]
Notional Amount	$ 13,620	$ 14,221
Fair Value	(769)	(725)
Receive Rate	2.993%	3.035%
Weighted Average Pay Rate	5.14%	5.14%
Interest Rate Swap 2
Derivatives, Fair Value [Line Items]
Notional Amount	25,000	25,000
Fair Value	(900)	(1,032)
Receive Rate	0.468%	0.559%
Weighted Average Pay Rate	2.58%	2.58%
Interest Rate Swap 3
Derivatives, Fair Value [Line Items]
Notional Amount	20,000	20,000
Fair Value	(2,214)	(2,064)
Receive Rate	0.467%	0.527%
Weighted Average Pay Rate	3.22%	3.22%
Interest Rate Swap 4
Derivatives, Fair Value [Line Items]
Notional Amount	20,000	20,000
Fair Value	$ (2,990)	$ (2,584)
Receive Rate	0.469%	0.384%
Weighted Average Pay Rate	3.355%	3.355%