STOCK-BASED COMPENSATION - Summary of Compensation Cost for Stock-Based Payment Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 7,945	$ 6,826	$ 14,163	$ 14,277
Drilling services operating
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,282	1,529	2,522	3,292
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	393	271	746	607
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,270	$ 5,026	$ 10,895	$ 10,378