Condensed Financial Information of Registrant (Parent Company Only) - Schedule of Balance Sheets (Parenthetical) (Detail) - $ / shares	Mar. 31, 2022	Sep. 30, 2021
Preferred stock, par value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Class A [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	155,108,627	154,866,313
Common stock, shares outstanding	155,108,627	154,866,313
Common Class B [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100
Parent Company [Member]
Preferred stock, par value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Parent Company [Member] \| Common Class A [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	155,108,627	154,866,313
Common stock, shares outstanding	155,108,627	154,866,313
Parent Company [Member] \| Common Class B [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100

Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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