Income Taxes - Expiration Dates of NOLs, Capital Loss and Other Tax Credit Carryforwards Before Valuation Allowances (Detail) $ in Millions	Sep. 30, 2022 USD ($)
Significant Tax Attributes And Dates Of Expiration [Line Items]
NOLs/Capital Losses	$ 2,092
Credits	122
2022 - 2028 [Member]
Significant Tax Attributes And Dates Of Expiration [Line Items]
NOLs/Capital Losses	1,142
Credits	26
2029 and Thereafter [Member]
Significant Tax Attributes And Dates Of Expiration [Line Items]
NOLs/Capital Losses	227
Credits	94
Indefinite Carryforwards [Member]
Significant Tax Attributes And Dates Of Expiration [Line Items]
NOLs/Capital Losses	723
Credits	$ 2