Pension And Postretirement Benefit Costs (Schedule Of Net Periodic Pension And Postretirement Benefit Costs) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 199,719	$ 187,917	$ 599,157	$ 563,751
Interest cost	494,028	505,176	1,482,084	1,515,529
Less: Expected return on plan assets	520,193	484,275	1,560,578	1,452,826
Amortization of prior service cost	27,186	27,495	81,557	82,484
Recognized net actuarial loss	308,589	228,247	925,766	684,742
Unrecognized net loss	0	0	0	0
Net periodic expense	509,329	464,560	1,527,986	1,393,680
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	173,433	153,566	525,497	460,698
Interest cost	430,047	436,228	1,303,031	1,308,683
Less: Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(12,688)	(12,688)	(38,444)	(38,064)
Recognized net actuarial loss	0	0	0	0
Unrecognized net loss	192,563	170,218	583,463	510,656
Net periodic expense	$ 783,355	$ 747,324	$ 2,373,547	$ 2,241,973