Retirement Plans (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2012
Net pension cost included the following components:
Service cost-benefits earned during the period	$ 170,000	$ 165,000	$ 340,000	$ 329,000
Interest cost on projected benefit obligation	171,000	210,000	343,000	420,000
Amortization of net obligation at transition	1,000		1,000	1,000
Amortization of prior service cost	39,000	38,000	77,000	76,000
Recognized net actuarial loss	72,000	97,000	144,000	193,000
Net periodic pension cost	453,000	510,000	905,000	1,019,000
Company contributions to pension plans	155,000	226,000	260,000	403,000	472,000
Pension plan payouts to participants	$ 155,000	$ 226,000	$ 260,000	$ 403,000