Pension Plans And Other Postretirement Benefits (Components Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 794	$ 826
Interest cost	3,108	3,285
Expected return on plan assets	(4,270)	(4,266)
Amortization of prior service cost	145	145
Amortization of actuarial loss	2,001	1,760
Settlement charge		3,028
Special termination benefit charge		302
Net periodic benefit cost	1,778	5,080
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	255	255
Interest cost	737	750
Expected return on plan assets	(647)	(711)
Amortization of prior service cost	(127)	(137)
Amortization of actuarial loss	291	267
Net periodic benefit cost	$ 509	$ 424