v3.25.4
ALLOWANCE FOR CREDIT LOSSES - Allowance for Credit Losses Roll Forward (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Allowance for credit losses      
Adjusted ACLL at beginning of year $ 18,574 $ 18,145 $ 16,974
Gross credit losses on loans (11,099) (10,694) (7,881)
Gross recoveries on loans 2,002 1,694 1,444
Net credit losses on loans (NCLs) (9,097) (9,000) (6,437)
Net reserve builds (releases) for loans 368 791 1,272
Net specific reserve builds (releases) for loans 32 (65) 77
Total provision for credit losses on loans (PCLL) 9,497 9,726 7,786
Initial allowance for credit losses on newly purchased credit-deteriorated assets during the period 0 23 0
Other, net 273 (320) 174
ACLL at end of year 19,247 18,574 18,145
Allowance for credit losses on unfunded commitments      
Allowance for credit losses on unfunded commitments (ACLUC) at beginning of period 1,601 1,728 2,151
Provision (release) for credit losses on ACLUC 202 (119) (425)
Other, net 30 (8) 2
ACLUC at end of period 1,833 1,601 1,728
Total ACLL and ACLUC 21,080 20,175 19,873
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]      
Allowance for credit losses on other assets at beginning of year 1,865 1,788 123
NCLs on other assets (46) (26) (72)
Provision for credit losses on other assets 467 362 1,762
Other, net (2,139) (259) (25)
Allowance for credit losses on other assets at end of year 147 1,865 1,788
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]      
Allowance for credit losses on HTM debt securities at beginning of year 137 95 120
Provision (release) for credit losses on HTM debt securities 12 50 (24)
Other, net (3) (8) (1)
Allowance for credit losses on HTM debt securities at end of year 146 137 95
Total ACL 21,373 22,177 21,756
Sales or transfers of various consumer loan portfolios to held-for-sale      
Purchased credit deteriorated assets 24 52 26
Discontinued Operations, Held-for-sale | AO Citibank      
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]      
Other, net 2,600    
Cumulative effect of adoption      
Allowance for credit losses      
Adjusted ACLL at beginning of year     (352)
Adjusted balance      
Allowance for credit losses      
Adjusted ACLL at beginning of year     16,622
Consumer      
Allowance for credit losses      
Adjusted ACLL at beginning of year 16,018 15,431 14,119
Gross credit losses on loans (10,657) (10,201) (7,553)
Gross recoveries on loans 1,925 1,598 1,366
Net credit losses on loans (NCLs) (8,732) (8,603) (6,187)
Net reserve builds (releases) for loans (54) 858 1,440
Net specific reserve builds (releases) for loans 12 (2) 38
Initial allowance for credit losses on newly purchased credit-deteriorated assets during the period   23  
Other, net 218 (292) 186
ACLL at end of year 16,194 16,018 15,431
Sales or transfers of various consumer loan portfolios to held-for-sale      
Reclasses of consumer ACLL to HFS (29) 0 0
Consumer | Cumulative effect of adoption      
Allowance for credit losses      
Adjusted ACLL at beginning of year     (352)
Consumer | Adjusted balance      
Allowance for credit losses      
Adjusted ACLL at beginning of year     13,767
Corporate      
Allowance for credit losses      
Adjusted ACLL at beginning of year 2,556 2,714 2,855
Gross credit losses on loans (442) (493) (328)
Gross recoveries on loans 77 96 78
Net credit losses on loans (NCLs) (365) (397) (250)
Net reserve builds (releases) for loans 422 (67) (168)
Net specific reserve builds (releases) for loans 20 (63) 39
Initial allowance for credit losses on newly purchased credit-deteriorated assets during the period   0  
Other, net 55 (28) (12)
ACLL at end of year 3,053 2,556 2,714
Sales or transfers of various consumer loan portfolios to held-for-sale      
FX translation $ 302 $ (320) $ 174