Derivative Instruments - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Feb. 28, 2021	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Energy Marketing Contracts Assets, Current		$ 12,185	$ 12,185	$ 3,269
Energy Marketing Contract Liabilities, Current		(1,969)	(1,969)	(127)
Notional Amount of Nonderivative Instruments	$ 40,000	70,000	30,000
Notional Amount Nonderivative Instruments, Total			60,000
Interest Rate Swap [Member]
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			100
Designated as Hedging Instrument [Member] | Mark To Market Energy Assets [Member] | Propane Swap Agreement [Member]
Derivative [Line Items]
Energy Marketing Contracts Assets, Current		12,185	12,185	3,255
Designated as Hedging Instrument [Member] | Mark-to-market energy liabilities [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current		(15)	(15)	(40)
Designated as Hedging Instrument [Member] | Mark-to-market energy liabilities [Member] | Propane Swap Agreement [Member]
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current		(1,954)	(1,954)	(64)
Sharp Energy Inc [Member]
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ 6,200
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer			12 months
Other Payables to Broker-Dealers and Clearing Organizations		$ 6,094	$ 6,094	$ 1,505
Interest Rate Swap Rate, High Range [Member]
Derivative [Line Items]
Fixed Swap Rate		0.17%	0.17%	0.205%
Interest Rate Swap Rate, Low Range [Member]
Derivative [Line Items]
Fixed Swap Rate				0.20%