Summary of Significant Accounting Policies (Other Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Restricted assets	$ 1,619	$ 25,907
Prepaid pension costs	45,292	38,100
Other assets	37,418	31,310
Total other assets	$ 84,329	$ 95,317