Commitments and Contingencies (Lease Disclosures) (Detail) $ in Millions	Sep. 30, 2022 USD ($)
Operating lease right of use asset	$ 17
Operating lease liability	$ 17
Operating lease weighted average remaining lease term	7 years 1 month 6 days
Operating lease weighted average discount rate percent	7.50%
Operating leases future minimum payments due	$ 24
Operating lease right of use asset	Other Assets
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Operating Lease, Liability