Investment in ATC and ATC Holdco (Details-2) - ATC [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 169,779	$ 186,785	$ 552,383	$ 561,379
Operating expenses	(97,629)	(91,340)	(288,376)	(278,828)
Other income, net	272	123	1,020	1,164
Interest expense, net	(34,794)	(28,674)	(92,293)	(86,337)
Earnings before members' income taxes	$ 37,628	$ 66,894	$ 172,734	$ 197,378