Employee Benefit Plans (Present Value of Accrued Liability) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Present Value Of Accrued Liability [Roll Forward]
Discount rate adjustment	$ (680)	$ 1,719
Benefit expense and interest cost	(6,122)	8,111	$ (1,582)
Interest cost	$ 29,864	$ 34,197	37,260
Discount rate	3.04%	2.76%
Executives Directors And Officer Of Acquired Entities
Present Value Of Accrued Liability [Roll Forward]
Present value of accrued liability as of January 1	$ 42,655	$ 45,295
Benefit expense and interest cost	2,015	3,503
Benefits paid	5,244	7,862
Present value of accrued liability as of December 31	$ 38,746	$ 42,655	$ 45,295