Stockholders' Equity - Schedule of Stockholders' Equity (Details) - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2024	Sep. 30, 2023	Mar. 31, 2023	Sep. 30, 2022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance of shares outstanding, beginning of period (in shares)	157,586
Balance, beginning of period	$ 947,740,000		$ 774,357,000
Non-cash share-based compensation	1,409,000		1,124,000
Purchase and retirement of common stock	(33,222,000)
Exercise of stock options and vesting of restricted stock units, net of shares withheld to satisfy tax withholding	(773,000)		(447,000)
Equitable adjustments to stock-based awards	21,000
Change in noncontrolling interests			(13,000)
Net loss	(10,848,000)		(26,762,000)
Foreign currency translation adjustment, net of tax of $0	$ 26,883,000		72,797,000
Balance of shares outstanding, end of period (in shares)	155,160
Balance, end of period	$ 931,210,000		820,932,000
Foreign currency translation adjustment, tax	$ 0	$ 0	$ 0	$ 0
Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance of shares outstanding, beginning of period (in shares)	157,586		157,013
Balance, beginning of period	$ 630,000		$ 923,000
Purchase of treasury stock at cost (in shares)	(2,607)
Purchase and retirement of common stock	$ (10,000)
Exercise of stock options and vesting of restricted stock units, net of shares withheld to satisfy tax withholding (in shares)	181		161
Exercise of stock options and vesting of restricted stock units, net of shares withheld to satisfy tax withholding	$ 1,000		$ 1,000
Balance of shares outstanding, end of period (in shares)	155,160		157,174
Balance, end of period	$ 621,000		$ 924,000
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	1,179,721,000		2,204,755,000
Non-cash share-based compensation	1,409,000		1,124,000
Purchase and retirement of common stock	(19,512,000)
Exercise of stock options and vesting of restricted stock units, net of shares withheld to satisfy tax withholding	(774,000)		(448,000)
Equitable adjustments to stock-based awards	21,000
Change in noncontrolling interests			(13,000)
Balance, end of period	1,160,865,000		2,205,434,000
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	41,862,000		39,244,000
Purchase and retirement of common stock	(13,700,000)
Net loss	(10,751,000)		(26,607,000)
Balance, end of period	17,411,000		12,637,000
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(272,144,000)		(442,424,000)
Foreign currency translation adjustment, net of tax of $0	26,883,000		72,791,000
Balance, end of period	(245,261,000)		(369,633,000)
Treasury stock at cost
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period			(1,026,272,000)
Balance, end of period			(1,026,272,000)
Non-controlling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(2,329,000)		(1,869,000)
Net loss	(97,000)		(155,000)
Foreign currency translation adjustment, net of tax of $0	0		6,000
Balance, end of period	$ (2,426,000)		$ (2,158,000)