Investments (Details-1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity Securities [Abstract]
Equity securities	$ 22,960	$ 20,529
Equity method investments: [Abstract]
Equity method investments	80,625	75,901
Other investments	2,298	2,324
Total investments	105,883	98,754
Proceeds from Sale, Maturity and Collection of Investments [Abstract]
Proceeds from sale of investments	924	1,684	$ 622
Gain (loss) on sale of investments	1,382	1,543	379
ATC and ATC Holdco [Member]
Equity method investments: [Abstract]
Equity method investments	80,586	75,862
Other Equity Method Investments [Member]
Equity method investments: [Abstract]
Equity method investments	39	39
MGE [Member]
Equity Securities [Abstract]
Equity securities	115	230
Equity method investments: [Abstract]
Equity method investments	0	0
Other investments	0	0
Total investments	115	230
Proceeds from Sale, Maturity and Collection of Investments [Abstract]
Proceeds from sale of investments	0	0	0
Gain (loss) on sale of investments	0	0	$ 0
MGE [Member] | ATC and ATC Holdco [Member]
Equity method investments: [Abstract]
Equity method investments	0	0
MGE [Member] | Other Equity Method Investments [Member]
Equity method investments: [Abstract]
Equity method investments	$ 0	$ 0