Defined Benefit Plan (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of components of net periodic pension income
Service cost	$ 207	$ 171
Interest cost	125	166
Expected return on plan assets	(383)	(357)
Prior service cost amortization	11	11
Deferred loss amortization	45	55
Net periodic pension income	$ 5	$ 46