Investment in ATC and ATC Holdco (Details-2) - ATC [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 206,197	$ 169,779	$ 610,399	$ 552,383
Operating expenses	(102,819)	(97,629)	(303,412)	(288,376)
Other income, net	701	272	1,657	1,020
Interest expense, net	(33,555)	(34,794)	(99,969)	(92,293)
Earnings before members' income taxes	$ 70,524	$ 37,628	$ 208,675	$ 172,734