INCOME TAXES - DEFERRED TAX ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands		Sep. 30, 2018	Sep. 30, 2017
Deferred tax assets
Investment tax credits	[1]	$ 123,258	$ 111,642
Deferred service contract revenue		0	3,877
Incentive compensation		4,646	6,260
Fair value of derivatives		8,411	11,519
Federal net operating losses	[2]	24,500	28,487
State net operating losses		34,754	23,597
Amortization of intangibles		3,737	2,747
Conservation incentive plan		1,955	0
Other		8,213	11,098
Total deferred tax assets		209,474	199,227
Deferred tax liabilities
Property related items		(392,886)	(620,850)
Remediation costs		(9,229)	(11,625)
Equity investments		(31,956)	(38,370)
Postemployment benefits		(353)	(6,855)
Conservation incentive plan		0	(7,195)
Underrecovered gas costs		(1,156)	(4,035)
Other		(7,826)	(16,643)
Total deferred tax liabilities		(443,406)	(705,573)
Total net deferred tax liabilities		(233,932)	(506,346)
Natural Gas Distribution
Deferred tax liabilities
Tax credit carryforward		2,200	2,300
Clean Energy Ventures
Deferred tax liabilities
Tax credit carryforward		$ 121,100	$ 109,300

[1] Includes $2.2 million and $2.3 million for NJNG for fiscal 2018 and 2017, respectively, which is being amortized over the life of the related assets, and$121.1 million and $109.3 million for Clean Energy Ventures for fiscal 2018 and 2017, respectively, which is ITC carryforward.

[2] See discussion of federal net operating loss utilization in the Other Tax Items section of this note.