Fair Value Of Financial Instruments - Summary of Carrying Values and the Estimated Fair Values of the Debt Financial Instruments (Detail) - 2022 Term Loan due April 28, 2029 [Member] - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Debt instrument maturity date	Apr. 28, 2029
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Loans payable	$ 597,000	$ 600,000
Estimated Fair Value [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Loans payable	$ 594,761	$ 586,500