BUSINESS SEGMENTS AND GEOGRAPHIC INFORMATION - Revenues from External Customers by Country (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenues	$ 317,364	$ 687,974	$ 1,565,660	$ 2,149,440
United States
Segment Reporting Information [Line Items]
Revenues	294,335	641,270	1,442,670	1,984,695
Argentina
Segment Reporting Information [Line Items]
Revenues	7,231	40,977	77,522	123,666
Bahrain
Segment Reporting Information [Line Items]
Revenues	6,430	1,855	21,497	6,909
United Arab Emirates
Segment Reporting Information [Line Items]
Revenues	8,403	0	14,857	4,728
Colombia
Segment Reporting Information [Line Items]
Revenues	413	3,451	6,313	28,075
Other Foreign
Segment Reporting Information [Line Items]
Revenues	$ 552	$ 421	$ 2,801	$ 1,367