Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plan Assets
Defined benefit plan, plan assets, contributions by employer	$ 2,400
Net actuarial loss	$ 44,800	$ 49,300
Expected return on assets (as a percent)	6.30%	6.30%
Investments in hedge funds which do not have readily determinable fair values	$ 8,100	$ 11,600
Expense provision for 401 (k) plans	4,100	4,100	$ 4,400
Company contributions	33,800	32,300	$ 41,200
Employee Pension Plans
Pension Plan Assets
Defined benefit plan, plan assets, contributions by employer	$ 1,526	$ 242
Discount rate (as a percent)	5.00%	5.20%
Expected return on assets (as a percent)	6.25%	5.75%	5.75%