Leases - Additional Information (Detail)	6 Months Ended
	Mar. 31, 2021
Lessee Lease Description [Line Items]
Lessee operating lease expiration year	2044
ASU No. 2016-02
Lessee Lease Description [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Oct. 01, 2019