Pension And Post-Retirement Benefit Costs (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 254	$ 257
Interest cost	647	680
Expected return on plan assets	(620)	(569)
Amortization of prior service cost	74	74
Amortization of net loss	439	304
Net periodic benefit cost	794	746
Post-Retirement Healthcare [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	4
Interest cost	185	209
Expected return on plan assets
Amortization of transition obligation		28
Amortization of prior service cost	21	47
Amortization of net loss	44	28
Net periodic benefit cost	$ 252	$ 316