Employee Benefit Plans And Other Postretirement Benefits (Components Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension and SERPA Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 40,039	$ 31,498	$ 35,987
Interest cost	87,345	86,923	79,248
Defined Benefit Plan, Early Retirement Reinsurance Program Proceeds	10,563	0	0
Expected return on plan assets	(144,929)	(136,734)	(127,327)
Prior service cost (credit)	435	1,119	1,746
Net loss	54,709	36,563	58,608
Settlement loss	368	0	0
Net periodic benefit cost	48,530	19,369	48,262
Postretirement Healthcare Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	8,259	7,015	7,858
Interest cost	14,166	16,878	15,599
Defined Benefit Plan, Early Retirement Reinsurance Program Proceeds	622	0	0
Expected return on plan assets	(11,506)	(10,429)	(9,537)
Prior service cost (credit)	(3,217)	(3,853)	(3,853)
Net loss	3,971	4,729	8,549
Settlement loss	0	0	0
Net periodic benefit cost	$ 12,295	$ 14,340	$ 18,616