Unrealized Losses on Debt Investments (Detail) - USD ($) $ in Millions	Jun. 30, 2025	Jun. 30, 2024
Unrealized Losses on Investments [Line Items]
Less than 12 Months - Fair Value	$ 4,560	$ 2,157
Less than 12 Months - Unrealized Losses	(65)	(25)
12 Months or Greater - Fair Value	38,176	52,432
12 Months or Greater - Unrealized Losses	(1,560)	(3,323)
Total Fair Value	42,736	54,589
Total Unrealized Losses	(1,625)	(3,348)
U.S. government and agency securities
Unrealized Losses on Investments [Line Items]
Less than 12 Months - Fair Value	2,569	529
Less than 12 Months - Unrealized Losses	(51)	(12)
12 Months or Greater - Fair Value	34,608	45,821
12 Months or Greater - Unrealized Losses	(1,411)	(2,936)
Total Fair Value	37,177	46,350
Total Unrealized Losses	(1,462)	(2,948)
Foreign government bonds
Unrealized Losses on Investments [Line Items]
Less than 12 Months - Fair Value	43	79
Less than 12 Months - Unrealized Losses	(2)	(2)
12 Months or Greater - Fair Value	106	180
12 Months or Greater - Unrealized Losses	(7)	(14)
Total Fair Value	149	259
Total Unrealized Losses	(9)	(16)
Mortgage- and asset-backed securities
Unrealized Losses on Investments [Line Items]
Less than 12 Months - Fair Value	841	201
Less than 12 Months - Unrealized Losses	(4)	(1)
12 Months or Greater - Fair Value	189	409
12 Months or Greater - Unrealized Losses	(23)	(34)
Total Fair Value	1,030	610
Total Unrealized Losses	(27)	(35)
Corporate notes and bonds
Unrealized Losses on Investments [Line Items]
Less than 12 Months - Fair Value	1,107	1,310
Less than 12 Months - Unrealized Losses	(8)	(9)
12 Months or Greater - Fair Value	3,105	5,779
12 Months or Greater - Unrealized Losses	(98)	(310)
Total Fair Value	4,212	7,089
Total Unrealized Losses	(106)	(319)
Municipal securities
Unrealized Losses on Investments [Line Items]
Less than 12 Months - Fair Value	0	38
Less than 12 Months - Unrealized Losses	0	(1)
12 Months or Greater - Fair Value	168	243
12 Months or Greater - Unrealized Losses	(21)	(29)
Total Fair Value	168	281
Total Unrealized Losses	$ (21)	$ (30)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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