Equity Investees (Schedule of Operations for Equity Investees) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
INCOME STATEMENT DATA:
Revenues	$ 804,662	$ 721,725	$ 1,595,274	$ 1,353,672
Operating income	102,784	96,585	152,165	148,256
Net income	49,344	35,347	47,700	30,097
Poseidon
INCOME STATEMENT DATA:
Revenues	39,251	35,380	80,146	66,569
Operating income	29,052	25,856	61,003	47,809
Net income	$ 25,313	$ 24,441	$ 53,989	$ 45,348