Pension and Other Postretirement Employee Benefits (Components Of Net Periodic Cost (Benefit)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,747	$ 1,531	$ 3,254	$ 3,061
Interest cost	4,258	4,259	8,510	8,518
Expected return on plan assets	(4,734)	(5,192)	(9,500)	(10,383)
Amortization of prior service cost (credit)	129	152	259	303
Amortization of actuarial loss	4,253	4,408	8,170	8,816
Net periodic cost (benefit)	5,653	5,158	10,693	10,315
Other Postretirement Employee Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	4	7	11
Interest cost	355	345	710	728
Amortization of prior service cost (credit)	(2,218)	(2,328)	(4,438)	(4,656)
Amortization of actuarial loss	430	466	858	1,024
Net periodic cost (benefit)	$ (1,431)	$ (1,513)	$ (2,863)	$ (2,893)