Pension And Postretirement Benefit Costs (Schedule Of Net Periodic Pension And Postretirement Benefit Costs) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 217,529	$ 199,786
Interest cost	484,356	494,194
Less: Expected return on plan assets	587,363	520,367
Amortization of prior service cost	24,932	27,195
Recognized net actuarial loss	333,408	308,692
Unrecognized net loss	0	0
Net periodic expense	472,862	509,500
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	204,959	166,332
Interest cost	422,470	412,440
Less: Expected return on plan assets	0	0
Amortization of prior service cost	(13,332)	(12,168)
Recognized net actuarial loss	0	0
Unrecognized net loss	173,771	184,681
Net periodic expense	$ 787,868	$ 751,285