Defined Benefit Plan (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
Schedule of components of net periodic pension income
Service cost	$ 168	$ 202	$ 339	$ 388
Interest cost	163	182	329	351
Expected return on plan assets	(351)	(412)	(709)	(793)
Prior service cost amortization	11	11	22	22
Deferred loss amortization	54	79	110	152
Net periodic pension income	$ 45	$ 62	$ 91	$ 120