BUSINESS SEGMENTS AND GEOGRAPHIC INFORMATION - Reconciliation of Segment Operating Income (Loss) to Income from Continuing Operations before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Abstract]
Operating income (loss) from continuing operations	$ 144,223	$ (42,611)
Gain on reimbursement of drilling equipment	15,724	5,254
Other gain (loss) on sale of assets	2,379	(1,029)
Corporate selling, general and administrative costs, corporate depreciation and corporate restructuring charges	48,455	43,715
Other income (expense)
Interest and dividend income	4,705	2,589
Interest expense	(4,355)	(6,114)
Gain (loss) on investment securities	(15,091)	47,862
Loss on extinguishment of debt	0	(60,083)
Other	(660)	(542)
Total unallocated amounts	(15,401)	(16,288)
Income (loss) from continuing operations before income taxes	128,822	(58,899)
Operating Segments
Segment Reporting Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Abstract]
Operating income (loss) from continuing operations	160,604	(12,731)
Segment Reconciling Items
Segment Reporting Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Abstract]
Gain on reimbursement of drilling equipment	15,724	5,254
Other gain (loss) on sale of assets	2,379	(1,029)
Corporate, Non-Segment
Segment Reporting Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Abstract]
Corporate selling, general and administrative costs, corporate depreciation and corporate restructuring charges	$ (34,484)	$ (34,105)