Retirement Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
SERP [Member]
Components of the net periodic pension cost for the SERP and Directors Retirement Plan
Service cost	$ 20	$ 16	$ 40	$ 32
Interest cost	31	31	62	62
Amortization of unrecognized gains and losses	20	14	40	28
Amortization of prior service cost	10	10	20	20
Net periodic pension cost	81	71	162	142
Directors' Retirement Plan [Member]
Components of the net periodic pension cost for the SERP and Directors Retirement Plan
Service cost	1	1	2	2
Interest cost	9	10	18	20
Amortization of prior service cost	22	22	45	43
Net periodic pension cost	$ 32	$ 33	$ 65	$ 65