Derivative Instruments - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Energy Marketing Contracts Assets, Current	$ 0	$ 82
Energy Marketing Contract Liabilities, Current	(2,216)	(1,604)
Derivative, Amount of Hedged Item	0	212
Designated as Hedging Instrument [Member] | Mark To Market Energy Assets [Member] | Put Option [Member]
Derivative [Line Items]
Energy Marketing Contracts Assets, Current	0	71
Designated as Hedging Instrument [Member] | Mark To Market Energy Assets [Member] | Propane Swap Agreement [Member]
Derivative [Line Items]
Energy Marketing Contracts Assets, Current	0	11
Designated as Hedging Instrument [Member] | Mark-to-market energy liabilities [Member] | Propane Swap Agreement [Member]
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current	(2,216)	(1,604)
Sharp Energy Inc [Member]
Derivative [Line Items]
Receivables from Brokers-Dealers and Clearing Organizations	(2,488)	(2,170)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(1,700)
PESCO [Member]
Derivative [Line Items]
Receivables from Brokers-Dealers and Clearing Organizations		(2,810)
Other Payables to Broker-Dealers and Clearing Organizations	(524)
Derivative Asset	3,200	13,100
Derivative Liability	$ 900	$ 13,300