REPORTING SEGMENT AND OTHER OPERATIONS DATA - NET FINANCIAL EARNINGS (LOSS) RECONCILIATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting [Abstract]
Net financial earnings	$ 135,333	$ 40,383
Less:
Unrealized (gain) loss on derivative instruments and related transactions	34,855	28,302
Tax effect	(8,059)	(9,757)
Effects of economic hedging related to natural gas inventory	(25,387)	(17,939)
Tax effect	8,244	6,204
Net income to NFE tax adjustment	1,981	(1,356)
NET INCOME	$ 123,699	$ 34,929