Goodwill and Other Intangible Assets - Schedule of Carrying Value of Goodwill (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		$ 26,957	$ 26,159
Finite-Lived Intangible Assets, Accumulated Amortization		10,092	8,300
Goodwill		508,174	46,213
Goodwill, Transfers	[1]	461,961
Regulated Energy
Goodwill [Line Items]
Goodwill		468,714	7,689
Goodwill, Transfers		461,025
Unregulated Energy
Goodwill [Line Items]
Goodwill		39,460	38,524
Goodwill, Transfers		936
Customer Lists [Member]
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		17,004	16,965
Finite-Lived Intangible Assets, Accumulated Amortization		7,146	6,131
Noncompete Agreements [Member]
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		3,125	3,105
Finite-Lived Intangible Assets, Accumulated Amortization		1,855	1,411
Patents [Member]
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	[2]	6,558	5,819
Finite-Lived Intangible Assets, Accumulated Amortization	[2]	859	533
Other Intangible Assets [Member]
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		270	270
Finite-Lived Intangible Assets, Accumulated Amortization		$ 232	$ 225

[1] (1) 2023 additions primarily attributable to goodwill from the November 2023 acquisition of FCG. See Note 4 for additional details.

[2] (1) Includes amounts related to patented technology developed by Marlin Gas Services and the acquisition of Planet Found