Retirement Plan (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Benefit Plan
Cost components:
Service cost-benefits earned during the period	$ (213)	$ (188)
Interest cost on projected benefit obligation	(282)	(288)
Expected return on plan assets	342	335
Net amortization and deferral	(144)	(165)
Total net periodic pension cost	(297)	(306)
SERP
Cost components:
Service cost-benefits earned during the period	(129)	(129)
Interest cost on projected benefit obligation	(162)	(162)
Net amortization and deferral	(216)	(48)
Total net periodic pension cost	$ (507)	$ (339)