Capital Stock - Additional Information (Detail) - USD ($)							3 Months Ended	9 Months Ended
	Jun. 14, 2022	May 13, 2022	May 11, 2022	Jun. 01, 2021	Jan. 26, 2021	Jun. 16, 2020	Jun. 30, 2022	Jun. 30, 2022	May 05, 2022	Sep. 30, 2021
Class Of Stock [Line Items]
Proceeds from initial public offering, net of related costs						$ 819,700,000
Underwriting commission and discounts						50,600,000
Estimated offering expenses payable						$ 9,200,000
Preferred stock, shares authorized							1,000,000	1,000,000		1,000,000
Preferred stock, par value per share							$ 0.001	$ 0.001		$ 0.001
Common stock description of voting rights								The Class A common stock and Class B common stock provide identical economic rights, but holders of Class B common stock have limited voting rights, specifically that such holders have no right to vote, solely with respect to their shares of Class B common stock, with respect to the election, replacement or removal of directors.
Common stock description of conversion rights								Class A common stock and Class B common stock are not entitled to preemptive rights. Holders of Class B common stock may convert their shares of Class B common stock into shares of Class A common stock on a one-for-one basis, in whole or in part, at any time and from time to time at their option.
Accelerated share repurchased			$ 50,000,000
Accelerated share repurchases termination date	Jun. 14, 2022
Accelerated share repurchased to settle ASR	86,132
Average purchase price per share	$ 19.93
Number of shares available for repurchase							$ 341,500,000	$ 341,500,000
Conversion of Units of Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted								108,162,741
Conversion of Membership Interests in Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted								108,162,741
Common Class A [Member]
Class Of Stock [Line Items]
Common stock, shares authorized							1,100,000,000	1,100,000,000		1,100,000,000
Common stock, par value per share							$ 0.001	$ 0.001		$ 0.001
Shares delivered		2,422,774
Initial share purchased, closing price			$ 16.51
Stock repurchase program, shares repurchased							504,669
Average price							$ 16.76
Reacquisition cost							$ 8,500,000
Common Class A [Member] | Maximum [Member]
Class Of Stock [Line Items]
Stock repurchase program, authorized amount									$ 400,000,000
Common Class A [Member] | Conversion of Units of Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted								75,093,778
Common Class A [Member] | Conversion of Membership Interests in Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted								75,093,778
Common Class A [Member] | Conversion of Profit Interests [Member]
Class Of Stock [Line Items]
Common stock member interests converted								2,703,243
Common Class B [Member]
Class Of Stock [Line Items]
Common stock, shares authorized							100,000,000	100,000,000		100,000,000
Common stock, par value per share							$ 0.001	$ 0.001		$ 0.001
Common Class B [Member] | Conversion of Units of Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted								33,068,963
Common Class B [Member] | Conversion of Membership Interests in Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted								33,068,963
Class A Restricted Stock [Member] | Conversion of Profit Interests [Member]
Class Of Stock [Line Items]
Common stock member interests converted								5,532,057
IPO [Member]
Class Of Stock [Line Items]
Shares issued price						$ 23.00
IPO [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Shares issued during period						38,237,500
Over-Allotment Option [Member]
Class Of Stock [Line Items]
Shares issued during period						4,987,500
Over-Allotment Option [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Shares issued price				$ 43.50	$ 40.00
Overallotment stock shares sold by shareholders during the period				2,250,000	3,000,000
Employee Stock [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Common stock shares reserved for future issuance							3,477,413	3,477,413
Secondary Offering [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Common stock, par value per share				$ 0.001	$ 0.001
Stock shares sold by shareholders during the period				17,250,000	23,000,000
Estimated offering expenses				$ 1,100,000	$ 1,200,000