Employee Benefit Plans And Other Postretirement Benefits (Schedule Of Reconciliation Of The Fair Value Measurements Using Significant Unobservable Inputs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2012
Pension Plan Assets [Member]
Change in plan assets:
Fair value of plan assets, end of period	$ 1,920,601
Pension Plan Assets [Member] | Limited Partnership Interests [Member]
Change in plan assets:
Fair value of plan assets, end of period	34,234
Postretirement Healthcare Benefits [Member]
Change in plan assets:
Fair value of plan assets, beginning of period			123,106
Fair value of plan assets, end of period	147,875	156,840	123,106
Significant Unobservable Inputs (Level 3) [Member] | Pension Plan Assets [Member]
Change in plan assets:
Fair value of plan assets, beginning of period	36,582
Relating to assets still held at the reporting date	2,951
Purchases, sales and settlements	(5,299)
Fair value of plan assets, end of period	34,234	31,086
Significant Unobservable Inputs (Level 3) [Member] | Pension Plan Assets [Member] | Limited Partnership Interests [Member]
Change in plan assets:
Fair value of plan assets, beginning of period	35,954	34,234
Relating to assets still held at the reporting date	2,951	(3,178)
Purchases, sales and settlements	(4,671)	30
Fair value of plan assets, end of period	34,234	31,086
Significant Unobservable Inputs (Level 3) [Member] | Pension Plan Assets [Member] | Other [Member]
Change in plan assets:
Fair value of plan assets, beginning of period	628
Relating to assets still held at the reporting date	0
Purchases, sales and settlements	(628)
Fair value of plan assets, end of period	0
Significant Unobservable Inputs (Level 3) [Member] | Postretirement Healthcare Benefits [Member] | Limited Partnership Interests [Member]
Change in plan assets:
Fair value of plan assets, beginning of period		0
Relating to assets still held at the reporting date		(178)
Purchases, sales and settlements		4,047
Fair value of plan assets, end of period		$ 3,869