v3.26.1
CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Change in Each Component of AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period $ 213,822  
Balance, end of period 212,572 $ 213,258
Liability for future policyholder benefits 489 425
Accumulated other comprehensive income (loss)    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period (41,897) (47,852)
Other comprehensive income before reclassifications 1,327 2,011
Increase (decrease) due to amounts reclassified from AOCI (45) 119
Total other comprehensive income 1,282 2,130
Balance, end of period (40,615) (45,722)
Net unrealized gains (losses) on debt securities    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period (1,240) (2,837)
Other comprehensive income before reclassifications (699) 601
Increase (decrease) due to amounts reclassified from AOCI (120) (86)
Total other comprehensive income (819) 515
Balance, end of period (2,059) (2,322)
Debt valuation adjustment (DVA)    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period (2,143) (1,121)
Other comprehensive income before reclassifications 1,401 775
Increase (decrease) due to amounts reclassified from AOCI 4 4
Total other comprehensive income 1,405 779
Balance, end of period (738) (342)
Cash flow hedges    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period 10 (220)
Other comprehensive income before reclassifications (275) (136)
Increase (decrease) due to amounts reclassified from AOCI 26 143
Total other comprehensive income (249) 7
Balance, end of period (239) (213)
Benefit plans    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period (5,504) (5,627)
Other comprehensive income before reclassifications (12) (71)
Increase (decrease) due to amounts reclassified from AOCI 50 45
Total other comprehensive income 38 (26)
Balance, end of period (5,466) (5,653)
CTA, net of hedges    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period (33,016) (38,047)
Other comprehensive income before reclassifications 893 837
Increase (decrease) due to amounts reclassified from AOCI (4) 12
Total other comprehensive income 889 849
Balance, end of period (32,127) (37,198)
CTA, net of hedges | AO Citibank    
Change in accumulated other comprehensive income (loss)    
Balance, end of period 1,600  
Excluded component of fair value hedges    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period (34) (52)
Other comprehensive income before reclassifications 14 6
Increase (decrease) due to amounts reclassified from AOCI (1) 1
Total other comprehensive income 13 7
Balance, end of period (21) (45)
Long-duration insurance contracts    
Change in accumulated other comprehensive income (loss)    
Balance, beginning of period 30 52
Other comprehensive income before reclassifications 5 (1)
Increase (decrease) due to amounts reclassified from AOCI 0 0
Total other comprehensive income 5 (1)
Balance, end of period 35 51
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 (49) 3
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
Accumulated Gain (Loss), Net, Cash Flow Hedge, Noncontrolling Interest    
Change in accumulated other comprehensive income (loss)    
Increase (decrease) due to amounts reclassified from AOCI 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 (6) 0
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest    
Change in accumulated other comprehensive income (loss)    
Increase (decrease) due to amounts reclassified from AOCI (19) 46
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
AOCI, Liability for Future Policy Benefit, Noncontrolling Interest    
Change in accumulated other comprehensive income (loss)    
Increase (decrease) due to amounts reclassified from AOCI 0 0
AOCI Attributable to Noncontrolling Interest    
Change in accumulated other comprehensive income (loss)    
Increase (decrease) due to amounts reclassified from AOCI $ (73) $ 49