Retirement Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
SERP [Member]
Components of net periodic pension cost for the SERP and Directors Retirement Plan
Service cost	$ 20	$ 16	$ 60	$ 48
Interest cost	31	31	93	93
Amortization of unrecognized gains and losses	20	14	60	42
Amortization of prior service cost	10	10	30	30
Net periodic pension cost	81	71	243	213
Directors' Retirement Plan [Member]
Components of net periodic pension cost for the SERP and Directors Retirement Plan
Service cost	1	1	3	3
Interest cost	9	10	27	30
Amortization of prior service cost	21	22	67	66
Net periodic pension cost	$ 31	$ 33	$ 97	$ 99