Equity Investees (Schedule of Operations for Equity Investees) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
INCOME STATEMENT DATA:
Revenues	$ 807,618	$ 721,248	$ 2,402,892	$ 2,074,920
Operating income	111,694	75,095	263,859	223,351
Net income	58,070	3,385	105,770	33,482
Poseidon
INCOME STATEMENT DATA:
Revenues	43,316	38,322	123,462	104,891
Operating income	33,213	27,731	94,216	75,540
Net income	$ 29,117	$ 25,502	$ 83,106	$ 70,850