REPORTING SEGMENT AND OTHER OPERATIONS DATA - NET FINANCIAL EARNINGS (LOSS) RECONCILIATION (Details) - USD ($) $ in Thousands		3 Months Ended								9 Months Ended
		Jun. 30, 2019		Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018		Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2019		Jun. 30, 2018
Segment Reporting [Abstract]
Net financial (loss) earnings	[1]	$ (17,506)				$ (8,003)				$ 149,004		$ 269,392
Less:
Unrealized (gain) loss on derivative instruments and related transactions		(24,646)				2,657				(25,353)		25,904
Tax effect		5,885				(577)				6,034		(3,920)
Effects of economic hedging related to natural gas inventory		11,317				4,474				12,073		(14,788)
Tax effect		(2,689)				(1,011)				(2,869)		5,518
Net income to NFE tax adjustment		1,029				728				7,700		6,987
NET (LOSS) INCOME		$ (8,402)	[1]	$ 73,573	$ 86,248	(14,274)	[1]	$ 140,266	$ 123,699	$ 151,419	[1]	249,691	[1]
Tax Cuts And Jobs Act Of 2017, income tax benefit						$ 844						$ (57,700)

[1] Includes income tax benefit related to the Tax Act of $844,000 and $57.7 million, for the three and nine months ended June 30, 2018, respectively.