Pensions and Other Postretirement Benefits (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 372,000	$ 388,000	$ 742,000	$ 784,000
Interest cost	452,000	411,000	902,000	831,000
Expected return on plan assets	(335,000)	(317,000)	(669,000)	(640,000)
Amortization of transition asset	(22,000)	(22,000)	(44,000)	(44,000)
Amortization of prior service cost	1,000	40,000	3,000	80,000
Amortization of actuarial loss	135,000	117,000	270,000	234,000
Net periodic pension cost	603,000	617,000	1,204,000	1,245,000
Contributions by employer			$ 1,100,000