Short-Term Borrowings (Details)	1 Months Ended	3 Months Ended	9 Months Ended
	Feb. 28, 2021 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2023 USD ($)	Oct. 31, 2023	Dec. 31, 2022 USD ($)
Short-term Debt [Line Items]
Ratio of Indebtedness to Net Capital			0.65	0.70
Notional Amount of Nonderivative Instruments	$ 40,000,000	$ 30,000,000	$ 50,000,000
Line of Credit Facility, Remaining Borrowing Capacity			250,500,000
Short-term borrowing			$ 118,570,000		$ 202,157,000
Short-term Debt, Weighted Average Interest Rate, at Point in Time			5.61%		5.04%
Draws on letters of credit			$ 5,900,000
Revolving Line of Credit, Short-term
Short-term Debt [Line Items]
Debt Instrument, Fee			9
Debt Instrument, Interest Rate, Stated Percentage			7500.00%
Aggregate Investment, Maximum			$ 175,000,000		$ 150,000,000
Interest Rate Credit Adjustment			10
Borrowings Outstanding, Sustainable Investing			$ 9,400,000
Line of Credit Facility, Interest Rate Description			1.05 percent
Line of Credit Facility [Line Items]
Line Of Credit Facility Interest Rate Description			$ 0.01
Line Of Credit Facility Interest Rate Description 2			$ 0.0005
Revolving Line of Credit, Long-term
Short-term Debt [Line Items]
Debt Instrument, Fee			9
Debt Instrument, Interest Rate, Stated Percentage			9500.00%
Interest Rate Credit Adjustment			10
3.48% note, due May 31, 2038 [Member]
Short-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			3.48%
Committed Line of Credit Facility Two [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 0.75 percent
Committed Line of Credit Facility Three [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			Lender's base rate, plus 0.75 percent
Committed Line of Credit Facility Five [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			Lender's base rate, plus 0.85 percent
Committed Line of Credit Facility Four [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 1.125 percent
Committed Line of Credit Facility Six [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 1.75 percent
Committed Line of Credit Facility Seven [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 1.75 percent
Committed Line of Credit Facility Eight [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 1.75 percent
Committed Line of Credit Facility Nine [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 1.75 percent
Committed Line of Credit Facility One [Member]
Short-term Debt [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR rate, plus 0.75 percent
Revolving Credit Facility
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 375,000,000
Interest Rate Swap Rate, Low Range [Member]
Short-term Debt [Line Items]
Fixed Swap Rate		0.20%
Interest Rate Swap Rate, High Range [Member]
Short-term Debt [Line Items]
Fixed Swap Rate		0.205%	3.98%		0.17%
Florida City Gas
Short-term Debt [Line Items]
Bridge Loan			$ 965,000,000
Line of Credit Facility [Line Items]
Bridge Loan			965,000,000
Florida City Gas | Regulated Energy [Member]
Short-term Debt [Line Items]
Bridge Loan			965,000,000
Line of Credit Facility [Line Items]
Bridge Loan			$ 965,000,000