Pension Plans and Postretirement Benefit Plan (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Benefits
Net periodic benefit cost for pension plans and the postretirement benefit plan
Interest Cost	$ 1,128,000	$ 1,263,000
Expected Return on Plan Assets	(1,313,000)	(1,568,000)
Net Actuarial Losses	414,000	332,000
Net Periodic Benefit Cost	229,000	27,000
Employer Contributions	100,000
Expected employer's contribution to pension and post retirement benefit plans	500,000
Postretirement Benefits
Net periodic benefit cost for pension plans and the postretirement benefit plan
Service Cost	32,000	145,000
Interest Cost	57,000	320,000
Amortization of Prior Service Credit	(80,000)	(81,000)
Net Periodic Benefit Cost	9,000	384,000
Employer Contributions	200,000
Expected employer's contribution to pension and post retirement benefit plans	$ 1,400,000