Pension Plan (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Pension Plan [Abstract]
Highest consecutive years of employee compensation used to compute benefit	3 years
Years of employment used in benefit computation	10 years
Net Pension Cost [Abstract]
Service cost	$ 19,000	$ 68,000
Interest cost	133,000	152,000
Amortization of prior service cost	22,000	22,000
Amortization of net actuarial loss	122,000	96,000
Net periodic benefit cost	296,000	338,000
Unfunded pension plan obligations	$ 16,800,000		$ 16,900,000