INCOME TAXES - IMPACT OF TAX ACT (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2018 USD ($)
Income Tax Contingency [Line Items]
Income tax (benefit) provision	$ (59,627)
Clean Energy Ventures
Income Tax Contingency [Line Items]
Income tax (benefit) provision	(61,423)
Energy Services
Income Tax Contingency [Line Items]
Income tax (benefit) provision	6,062
Midstream
Income Tax Contingency [Line Items]
Income tax (benefit) provision	(13,946)
Home Services and Other
Income Tax Contingency [Line Items]
Income tax (benefit) provision	$ 9,680