Employee Benefit Plans (Components Of Pension Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Retirement Benefits, Description [Abstract]
Service cost	$ 3,838	$ 3,570	$ 11,514	$ 10,709
Interest cost	7,466	8,549	22,398	25,648
Expected return on assets	(19,607)	(16,423)	(58,823)	(49,267)
Amortization of net actuarial loss	6,773	6,332	20,320	18,994
Total pension expense	$ (1,530)	$ 2,028	$ (4,591)	$ 6,084