v3.26.1
Unrealized Losses on Debt Investments (Detail) - USD ($)
$ in Millions
Mar. 31, 2026
Jun. 30, 2025
Unrealized Losses on Investments [Line Items]    
Less than 12 Months - Fair Value $ 10,944 $ 4,560
Less than 12 Months - Unrealized Losses (369) (65)
12 Months or Greater - Fair Value 24,788 38,176
12 Months or Greater - Unrealized Losses (830) (1,560)
Total Fair Value 35,732 42,736
Total Unrealized Losses (1,199) (1,625)
U.S. government and agency securities    
Unrealized Losses on Investments [Line Items]    
Less than 12 Months - Fair Value 6,800 2,569
Less than 12 Months - Unrealized Losses (335) (51)
12 Months or Greater - Fair Value 23,042 34,608
12 Months or Greater - Unrealized Losses (743) (1,411)
Total Fair Value 29,842 37,177
Total Unrealized Losses (1,078) (1,462)
Foreign government bonds    
Unrealized Losses on Investments [Line Items]    
Less than 12 Months - Fair Value 91 43
Less than 12 Months - Unrealized Losses (2) (2)
12 Months or Greater - Fair Value 31 106
12 Months or Greater - Unrealized Losses (3) (7)
Total Fair Value 122 149
Total Unrealized Losses (5) (9)
Mortgage- and asset-backed securities    
Unrealized Losses on Investments [Line Items]    
Less than 12 Months - Fair Value 581 841
Less than 12 Months - Unrealized Losses (3) (4)
12 Months or Greater - Fair Value 150 189
12 Months or Greater - Unrealized Losses (20) (23)
Total Fair Value 731 1,030
Total Unrealized Losses (23) (27)
Corporate notes and bonds    
Unrealized Losses on Investments [Line Items]    
Less than 12 Months - Fair Value 3,472 1,107
Less than 12 Months - Unrealized Losses (29) (8)
12 Months or Greater - Fair Value 1,411 3,105
12 Months or Greater - Unrealized Losses (44) (98)
Total Fair Value 4,883 4,212
Total Unrealized Losses (73) (106)
Municipal securities    
Unrealized Losses on Investments [Line Items]    
Less than 12 Months - Fair Value 0 0
Less than 12 Months - Unrealized Losses 0 0
12 Months or Greater - Fair Value 154 168
12 Months or Greater - Unrealized Losses (20) (21)
Total Fair Value 154 168
Total Unrealized Losses $ (20) $ (21)