Pension Plans And Other Postretirement Benefit Plans (Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,519	$ 4,949
Interest cost	6,900	6,672
Expected return on plan assets	(6,750)	(7,416)
Amortization of prior service cost	0	6
Net loss recognition	1,890	2,394
Net periodic benefit cost	6,559	6,605
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	779	699
Interest cost	1,559	1,331
Expected return on plan assets	(475)	(431)
Amortization of prior service cost	(312)	(279)
Net loss recognition	1,365	1,292
Net periodic benefit cost	$ 2,916	$ 2,612