Off-balance Sheet Lending-related Financial Instruments, Guarantees, and Other Commitments - Summary (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	$ 1,855,174	$ 1,817,307
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	1,289,009
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	298,893
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	229,059
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	38,213
Off-balance sheet lending-related financial commitments, Carrying value	6,249	6,278
Apple Credit Card Portfolio | Credit Concentration Risk | Credit card
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information
Credit exposure		104,000
Total Consumer
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	1,250,252	1,221,353
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	1,127,283
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	109,519
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	3,382
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	10,068
Off-balance sheet lending-related financial commitments, Carrying value	2,546	2,537
Total consumer, excluding credit card
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	46,236	43,587
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	27,496
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	5,290
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	3,382
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	10,068
Off-balance sheet lending-related financial commitments, Carrying value	346	337
Residential real estate
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	31,487	28,998
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	16,624
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	5,285
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	3,378
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	6,200
Off-balance sheet lending-related financial commitments, Carrying value	336	327
Auto and other
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	14,749	14,589
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	10,872
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	5
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	4
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	3,868
Off-balance sheet lending-related financial commitments, Carrying value	10	10
Credit card
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	1,204,016	1,177,766
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	1,099,787
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	104,229
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	0
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	0
Off-balance sheet lending-related financial commitments, Carrying value	2,200	2,200
Total wholesale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	604,922	595,954
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	161,726
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	189,374
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	225,677
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	28,145
Off-balance sheet lending-related financial commitments, Carrying value	3,703	3,741
Other unfunded commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	568,077	561,506
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	140,025
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	179,650
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	220,847
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	27,555
Off-balance sheet lending-related financial commitments, Carrying value	3,030	3,112
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information
Risk participations for other unfunded commitments to extend credit	118	181
Standby letters of credit and other financial guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	31,322	29,919
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	16,677
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	9,505
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	4,753
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	387
Off-balance sheet lending-related financial commitments, Carrying value	661	616
Other guarantees and commitments, Carrying value	454	441
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information
Risk participations for standby letters of credit and other financial guarantees	11,600	9,200
Other letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total lending-related commitments	5,523	4,529
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring in 1 year or less	5,024
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 1 year through 3 years	219
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 3 years through 5 years	77
Off-balance sheet lending-related financial commitments, Contractual amount, Expiring after 5 years	203
Off-balance sheet lending-related financial commitments, Carrying value	12	13
Other guarantees and commitments, Carrying value	0	0
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information
Risk participations for other letters of credit	773	514
Securities lending indemnification agreements and guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, Contractual amount	449,554	405,910
Other guarantees and commitments, Contractual amount, Expiring in 1 year or less	449,554
Other guarantees and commitments, Contractual amount, Expiring after 1 year through 3 years	0
Other guarantees and commitments, Contractual amount, Expiring after 3 years through 5 years	0
Other guarantees and commitments, Contractual amount, Expiring after 5 years	0
Other guarantees and commitments, Carrying value	0	0
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information
Collateral held in support of securities lending indemnification agreements	474,800	431,900
Derivatives qualifying as guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, Contractual amount	48,980	49,031
Other guarantees and commitments, Contractual amount, Expiring in 1 year or less	1,812
Other guarantees and commitments, Contractual amount, Expiring after 1 year through 3 years	166
Other guarantees and commitments, Contractual amount, Expiring after 3 years through 5 years	9,285
Other guarantees and commitments, Contractual amount, Expiring after 5 years	37,717
Other guarantees and commitments, Carrying value	76	(12)
Unsettled resale and securities borrowed agreements
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, Contractual amount	155,871	137,072
Other guarantees and commitments, Contractual amount, Expiring in 1 year or less	155,650
Other guarantees and commitments, Contractual amount, Expiring after 1 year through 3 years	221
Other guarantees and commitments, Contractual amount, Expiring after 3 years through 5 years	0
Other guarantees and commitments, Contractual amount, Expiring after 5 years	0
Other guarantees and commitments, Carrying value	(8)	0
Unsettled repurchase and securities loaned agreements
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, Contractual amount	142,162	52,895
Other guarantees and commitments, Contractual amount, Expiring in 1 year or less	141,586
Other guarantees and commitments, Contractual amount, Expiring after 1 year through 3 years	576
Other guarantees and commitments, Contractual amount, Expiring after 3 years through 5 years	0
Other guarantees and commitments, Contractual amount, Expiring after 5 years	0
Other guarantees and commitments, Carrying value	0	0
Mortgage repurchase liability
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan sale and securitization-related indemnifications, Mortgage repurchase liability, Carrying value	37	37
Loans sold with recourse
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan sale and securitization-related indemnifications, Loans sold with recourse, Contractual amount	2,048	2,015
Loan sale and securitization-related indemnifications, Loans sold with recourse, Carrying value	19	19
Exchange & clearing house guarantees and commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, Contractual amount	237,734	433,537
Other guarantees and commitments, Contractual amount, Expiring in 1 year or less	237,734
Other guarantees and commitments, Carrying value	0	0
Other guarantees and commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, Contractual amount	23,075	13,238
Other guarantees and commitments, Contractual amount, Expiring in 1 year or less	15,448
Other guarantees and commitments, Contractual amount, Expiring after 1 year through 3 years	5,877
Other guarantees and commitments, Contractual amount, Expiring after 3 years through 5 years	245
Other guarantees and commitments, Contractual amount, Expiring after 5 years	1,505
Other guarantees and commitments, Carrying value	$ 14	$ 15