Investment in ATC and ATC Holdco (Details-2) - ATC [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 200,426	$ 190,999
Operating expenses	(99,076)	(95,491)
Other income, net	391	404
Interest expense, net	(32,910)	(28,440)
Earnings before members' income taxes	$ 68,831	$ 67,472