Pension Information (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	Dec. 31, 2011
Net periodic pension expense
Service cost	$ 235	$ 212	$ 704	$ 635
Interest cost	229	203	686	611
Expected return on plan assets	(215)	(206)	(644)	(620)
Other components	90	85	270	257
Net periodic pension cost	339	294	1,016	883
Pension Information (Textual) [Abstract]
Total amount of contributions expected to be paid	1,355		1,355
Total amount of contributions compared					$ 1,152