Stock-Based Compensation - Schedule of Stock-based Compensation Expense, by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 22,190	$ 29,051	$ 46,556	$ 32,049
Service-based profits interest awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	7,945	27,913	16,929	30,035
Hybrid profits interest awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	1,081	0	3,498	0
Profits interest awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	9,026	27,913	20,427	30,035
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	767	0	1,724	0
Pre-IPO Management Incentive Compensation Plan awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	0	1,138	0	2,014
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	12,290	0	24,298	0
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	107	0	107	0
Partial Recourse Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 0	$ 0	$ 1,100	$ 400