INCOME TAXES - Components of provision (benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Current:
Federal	$ 757	$ (36,260)	$ (86,010)
Foreign	6,492	4,108	9,987
State	2,340	(472)	(3,742)
Total current	9,589	(32,624)	(79,765)
Deferred:
Federal	(508,256)	(14,953)	58,136
Foreign	7,415	(7,827)	408
State	14,083	(1,331)	1,544
Total deferred	(486,758)	(24,111)	60,088
Total benefit	(477,169)	(56,735)	(19,677)
Amounts of domestic and foreign income before income taxes
Domestic	27,436	(173,157)	(49,636)
Foreign	(11,595)	(11,441)	(23,031)
Income (loss) from continuing operations before income taxes	$ 15,841	$ (184,598)	$ (72,667)