DERIVATIVE INSTRUMENTS - BROKER MARGIN DEPOSITS (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Natural Gas Distribution
Derivative [Line Items]
Broker margin - Current assets	$ 4,190	$ 13,525
Energy Services
Derivative [Line Items]
Broker margin - Current assets	$ 41,726	$ 55,919

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