v3.26.1
CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Change in Each Component of AOCI (Details)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Apr. 29, 2026
Sep. 24, 2025
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period     $ 213,822      
Balance, end of period $ 214,450 $ 214,130 214,450 $ 214,130    
Liability for future policyholder benefits $ 552 464 $ 552 464    
Banamex            
Change in accumulated other comprehensive income (loss)            
Percentage owned of equity investment           24.00%
Grupo Financeiro Banamex | Disposal Group, Disposed of by Sale, Not Discontinued Operations            
Change in accumulated other comprehensive income (loss)            
Interest in entity sold 0.226   0.226   0.226  
Accumulated other comprehensive income (loss)            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period $ (40,615) (45,722) $ (41,897) (47,852)    
Net increase/(decrease) due to Banamex equity sales 2,202   2,202      
Other comprehensive income before reclassifications (1,055) 1,861 272 3,872    
Increase (decrease) due to amounts reclassified from AOCI (32) 75 (77) 194    
Citigroup’s total other comprehensive income (loss) (1,087) 1,936 195 4,066    
Change, net of taxes 1,115   2,397      
Balance, end of period (39,500) (43,786) (39,500) (43,786)    
Net unrealized gains (losses) on debt securities            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period (2,059) (2,322) (1,240) (2,837)    
Net increase/(decrease) due to Banamex equity sales (16)   (16)      
Other comprehensive income before reclassifications 359 378 (340) 979    
Increase (decrease) due to amounts reclassified from AOCI (109) (100) (229) (186)    
Citigroup’s total other comprehensive income (loss) 234 278 (585) 793    
Change, net of taxes 234   (585)      
Balance, end of period (1,825) (2,044) (1,825) (2,044)    
Debt valuation adjustment (DVA)            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period (738) (342) (2,143) (1,121)    
Other comprehensive income before reclassifications (1,102) (344) 299 431    
Increase (decrease) due to amounts reclassified from AOCI 13 2 17 6    
Citigroup’s total other comprehensive income (loss) (1,089) (342) 316 437    
Change, net of taxes (1,089)   316      
Balance, end of period (1,827) (684) (1,827) (684)    
Cash flow hedges            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period (239) (213) 10 (220)    
Net increase/(decrease) due to Banamex equity sales 0   0      
Other comprehensive income before reclassifications (289) (56) (564) (192)    
Increase (decrease) due to amounts reclassified from AOCI 18 128 44 271    
Citigroup’s total other comprehensive income (loss)   72   79    
Change, net of taxes (271)   (520)      
Balance, end of period (510) (141) (510) (141)    
Benefit plans            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period (5,466) (5,653) (5,504) (5,627)    
Net increase/(decrease) due to Banamex equity sales 225   225      
Other comprehensive income before reclassifications 13 (80) 1 (151)    
Increase (decrease) due to amounts reclassified from AOCI 47 43 97 88    
Citigroup’s total other comprehensive income (loss) 285 (37) 323 (63)    
Change, net of taxes 285   323      
Balance, end of period (5,181) (5,690) (5,181) (5,690)    
CTA, net of hedges            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period (32,127) (37,198) (33,016) (38,047)    
Net increase/(decrease) due to Banamex equity sales 2,003   2,003      
Other comprehensive income before reclassifications (36) 1,966 857 2,803    
Increase (decrease) due to amounts reclassified from AOCI 0 0 (4) 12    
Citigroup’s total other comprehensive income (loss) 1,967 1,966 2,856 2,815    
Change, net of taxes 1,967   2,856      
Balance, end of period (30,160) (35,232) (30,160) (35,232)    
CTA, net of hedges | AO Citibank            
Change in accumulated other comprehensive income (loss)            
Balance, end of period 1,600   1,600      
Excluded component of fair value hedges            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period (21) (45) (34) (52)    
Net increase/(decrease) due to Banamex equity sales 0   0      
Other comprehensive income before reclassifications 5 (2) 19 4    
Increase (decrease) due to amounts reclassified from AOCI (1) 2 (2) 3    
Citigroup’s total other comprehensive income (loss)   0   7    
Change, net of taxes 4   17      
Balance, end of period (17) (45) (17) (45)    
Long-duration insurance contracts            
Change in accumulated other comprehensive income (loss)            
Balance, beginning of period 35 51 30 52    
Net increase/(decrease) due to Banamex equity sales (10)   (10)      
Other comprehensive income before reclassifications (5) (1) 0 (2)    
Increase (decrease) due to amounts reclassified from AOCI 0 0 0 0    
Citigroup’s total other comprehensive income (loss) (15) (1) (10) (2)    
Change, net of taxes (15)   (10)      
Balance, end of period 20 50 20 50    
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI 22 4 (27) 7    
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI 0 0 0 0    
Accumulated Gain (Loss), Net, Cash Flow Hedge, Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI 0 0 1 0    
Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI 67 0 61 0    
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI 79 54 60 100    
AOCI, Derivative Qualifying as Hedge, Excluded Component, Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI 0 0 0 0    
AOCI, Liability for Future Policy Benefit, Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI (3) 0 (3) 0    
AOCI Attributable to Noncontrolling Interest            
Change in accumulated other comprehensive income (loss)            
Increase (decrease) due to amounts reclassified from AOCI   $ 58 92 $ 107    
Debt valuation adjustment (DVA)            
Change in accumulated other comprehensive income (loss)            
Net increase/(decrease) due to Banamex equity sales $ 0   $ 0