Summary of Significant Accounting Policies - Summary of Property and Equipment Estimated Useful Life (Detail)	12 Months Ended
	Sep. 30, 2020
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	40 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	Shorter of the estimated useful life or the term of the lease, considering renewal options expected to be exercised.
Minimum [Member] | Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Maximum [Member] | Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years