Benefit Plans (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Components of the net periodic benefit cost [Abstract]
Contribution made to pension and postretirement plans			$ 0
Pension Benefits [Member]
Components of the net periodic benefit cost [Abstract]
Service cost	12,000	12,000	24,000	23,000
Interest cost	365,000	379,000	730,000	758,000
Expected return on plan assets	(474,000)	(497,000)	(948,000)	(993,000)
Amortization of net loss (gain)	102,000	39,000	204,000	78,000
Amortization of prior service credit	0	0	0	0
Net periodic benefit	5,000	(67,000)	10,000	(134,000)
Other Postretirement Benefits [Member]
Components of the net periodic benefit cost [Abstract]
Service cost	8,000	4,000	16,000	13,000
Interest cost	25,000	33,000	51,000	49,000
Expected return on plan assets	(112,000)	(112,000)	(225,000)	(224,000)
Amortization of net loss (gain)	(5,000)	(17,000)	(10,000)	(36,000)
Amortization of prior service credit	(65,000)	(30,000)	(131,000)	(131,000)
Net periodic benefit	$ (149,000)	$ (122,000)	$ (299,000)	$ (329,000)