CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (277,976)	$ (26,089)	$ (254,119)	$ (28,247)
Other comprehensive (loss) income:
Foreign currency translation adjustments	(3,225)	939	1,055	10,101
Pension adjustments, net	(39)	(55)	(12)	(29)
Net unrealized (losses) gains on available-for-sale securities	(3)	193	160	292
Total other comprehensive (loss) income	(3,267)	1,077	1,203	10,364
Comprehensive loss	$ (281,243)	$ (25,012)	$ (252,916)	$ (17,883)