Acquisitions - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Dekatherm	Dec. 31, 2020 USD ($)
Cash paid for acquisition	$ 11,766	$ 36,371	$ 22,231
Revenues	680,704	569,968	488,198
Operating Income (Loss)	142,933	131,112	112,723
Net Income	89,796	$ 83,466	71,498
Marlin Gas Services [Member]
Additional Compressed Natural Gas Deliverability | Dekatherm		7,000
Regulated Energy [Member]
Operating Income (Loss)	$ 115,317	$ 106,174	92,124
Regulated Energy [Member] | Elkton Gas [Member]
Number of customers acquired through acquisition	7,000
Unregulated Energy
Operating Income (Loss)	$ 27,350	24,427	$ 20,664
Unregulated Energy | Diversified Energy
Revenues	26,000	1,400
Operating Income (Loss)	$ 1,000	$ 300
Number of customers acquired through acquisition	19,000
Business Combination, Consideration Transferred	$ 37,500
Business Combination, Working Capital	1,700
Business Combination, Contingent Consideration, Liability	2,100
Property, Plant and Equipment, Acquired During Period	23,100
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	5,900
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	6,200
Business Acquisition, Preacquisition Contingency, Amount of Settlement	$ 800
Gallons acquired through acquisition	10,000,000
Unregulated Energy | Davenport Energy
Number of customers acquired through acquisition	850
Business Combination, Consideration Transferred	$ 2,000
Property, Plant and Equipment, Acquired During Period	1,500
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$ 500
Gallons acquired through acquisition	400,000
Unregulated Energy | Planet Found
Business Combination, Consideration Transferred	$ 9,500
Business Combination, Working Capital	100
Business Combination, Contingent Consideration, Liability	900
Property, Plant and Equipment, Acquired During Period	4,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	1,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	$ 4,400
Tons of Poultry Litter	1,200