Defined Benefit Plan (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
Schedule of components of net periodic pension income
Service cost	$ 164	$ 213	$ 502	$ 601
Interest cost	159	193	487	543
Expected return on plan assets	(342)	(435)	(1,049)	(1,227)
Prior service cost amortization	11	12	32	35
Deferred loss amortization	53	83	162	234
Net periodic pension income	$ 45	$ 66	$ 135	$ 186