Goodwill and Other Identifiable Intangible Assets - Summary of Changes in Goodwill and Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Goodwill [Roll Forward]
Net balance - beginning of period			$ 378,588
Acquisition			18,480
Other adjustments			401
Net balance - end of period	$ 397,469		397,469
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			306,471
Acquisitions			10,267
Accumulated amortization	(3,400)	$ (2,100)	(9,962)	$ (4,700)
Net balance - end of period	306,776		306,776
Developed Technologies
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			14,274
Acquisitions			0
Accumulated amortization			(1,159)
Net balance - end of period	13,115		13,115
Customer Relationships
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			101,230
Acquisitions			0
Accumulated amortization			(8,062)
Net balance - end of period	93,168		93,168
Domain Names
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			1,970
Acquisitions			815
Accumulated amortization			(359)
Net balance - end of period	2,426		2,426
Internally Developed Software
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			2,218
Acquisitions			652
Accumulated amortization			(382)
Net balance - end of period	2,488		2,488
Trade Names
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			186,779
Acquisitions			8,800
Net balance - end of period	$ 195,579		$ 195,579