v3.21.2
Net Recognized Gains (Losses) on Debt Investments (Detail) - USD ($)
$ in Millions
3 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]    
Realized gains from sales of available-for-sale securities $ 19 $ 19
Realized losses from sales of available-for-sale securities (7) (5)
Total 371 125
Debt Securities    
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]    
Impairments and allowance for credit losses (3) 3
Total $ 9 $ 17