Acquisitions - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Combination, Separately Recognized Transactions [Line Items]
Equity Issued in Business Combination, Fair Value Disclosure	$ 366,400,000
Proceeds from Issuance of Senior Long-Term Debt	550,000,000
Business Acquisition, Transaction Costs	4,100,000
Business Combination, Acquisition Related Costs	15,900,000
Revenues	670,604,000	$ 680,704,000	$ 569,968,000
Operating Income	150,803,000	142,933,000	131,112,000
Transaction-related expenses	10,355,000	0	0
Regulated Energy [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Operating Income	126,199,000	$ 115,317,000	$ 106,174,000
Common Stock [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Proceeds from Issuance of Senior Long-Term Debt	4,400,000
Florida City Gas
Business Combination, Separately Recognized Transactions [Line Items]
Business Combination, Consideration Transferred	$ 923,400,000
Number of customers acquired through acquisition	120,000
Number of Miles of Distribution Mains	3,800
Number of Miles of Transmission Pipe	80
Business Combination, Integration Related Costs	$ 10,400,000
Transaction-related expenses	7,500,000
Property, Plant and Equipment, Acquired During Period	453,845,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	461,193,000
Florida City Gas | Regulated Energy [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Revenues	12,100,000
Operating Income	(3,300,000)
J.T. Lee and Son's
Business Combination, Separately Recognized Transactions [Line Items]
Business Combination, Consideration Transferred	$ 3,900,000
Number of customers acquired through acquisition	3,000
Business Combination, Contingent Consideration, Liability	$ 300,000
Gallons acquired through acquisition	800,000
Bulk Plant Storage Acquired Through Acquisition	60,000
Property, Plant and Equipment, Acquired During Period	$ 2,700,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	900,000
Business Combination, Working Capital	200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	100,000
Planet Found
Business Combination, Separately Recognized Transactions [Line Items]
Business Combination, Consideration Transferred	9,500,000
Business Combination, Contingent Consideration, Liability	900,000
Property, Plant and Equipment, Acquired During Period	4,000,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	1,100,000
Business Combination, Working Capital	100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	$ 4,400,000
Tons of Poultry Litter	1,200
Davenport Energy
Business Combination, Separately Recognized Transactions [Line Items]
Business Combination, Consideration Transferred	$ 2,000,000
Number of customers acquired through acquisition	850
Gallons acquired through acquisition	400,000
Property, Plant and Equipment, Acquired During Period	$ 1,500,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$ 500,000