Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Loss Contingencies [Line Items]
Potential liability due to taxable sales of applicable properties	$ 20.4
Operating lease payments	8.9
Building Expansion	$ 8.2	$ 17.4
Minimum | Office Lease
Loss Contingencies [Line Items]
Non-cancellable operating leases, expiration year			2022
Minimum | Ground Lease
Loss Contingencies [Line Items]
Non-cancellable operating leases term			2034
Maximum | Office Lease
Loss Contingencies [Line Items]
Non-cancellable operating leases, expiration year			2023
Maximum | Ground Lease
Loss Contingencies [Line Items]
Non-cancellable operating leases term			2069