CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - 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 Income (Loss)	$ (136,880)	$ (4,927)	$ (152,604)	$ (16,162)
Other comprehensive income (loss), net of tax
Net investment hedge currency translation adjustment, net of tax effects of $(1,739) and $2,837 for the three and six months ended March 31, 2024, respectively, and ($4,531) and ($24,239) for the three and six months ended March 31, 2023, respectively	5,080	(13,133)	(8,288)	(70,260)
Foreign currency translation adjustments	(20,769)	33,850	25,725	111,264
Changes in unrealized gains on marketable securities, net of tax effects of $(257) and $607 for the three and six months ended March 31, 2024, respectively, and $858 and $1,395 for the three and six months ended March 31, 2023, respectively	752	2,487	3,276	4,042
Actuarial (loss) in pension plans, net of tax effects of $(3) and $(1) during the three and six months ended March 31, 2024, respectively, and $0 during each of the three and six months ended March 31, 2023	(7)		(15)
Total other comprehensive income (loss), net of tax	(14,944)	23,204	20,698	45,046
Comprehensive income (loss)	$ (151,824)	$ 18,277	$ (131,906)	$ 28,884