v3.26.1
CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Reclassification out of AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Realized gains and (losses) $ 270 $ 121
Subtotal, pretax 7,517 5,448
Tax effect (1,578) (1,340)
Income (loss) from continuing operations 5,939 4,108
Subtotal, pretax 359 259
Other Noninterest Expense (1,109) (1,180)
Citigroup's accumulated other comprehensive income (loss)    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax (45) 119
Citigroup's accumulated other comprehensive income (loss) | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax (45) 119
Total tax effect 9 (30)
Total amounts reclassified out of AOCI, pretax (54) 149
Realized gains (losses) on investment securities    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax (120) (86)
Realized gains (losses) on investment securities | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Realized gains and (losses) (270) (121)
Gross impairment losses 113 3
Subtotal, pretax (157) (118)
Tax effect 37 32
Income (loss) from continuing operations (120) (86)
Debt valuation adjustment (DVA)    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax 4 4
Debt valuation adjustment (DVA) | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Realized gains and (losses) 5 5
Tax effect (1) (1)
Income (loss) from continuing operations 4 4
Cash flow hedges    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax 26 143
Cash flow hedges | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Tax effect (9) (46)
Subtotal, pretax 35 189
Total amounts reclassified out of AOCI, after-tax 26 143
Cash flow hedges | (Gain) loss reclassified from AOCI | Interest rate contracts    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Subtotal, pretax 27 189
Cash flow hedges | (Gain) loss reclassified from AOCI | Foreign exchange contracts    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Subtotal, pretax 8 0
Benefit plan adjustments    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax 50 45
Benefit plan adjustments | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Other Noninterest Expense 68 60
Total amounts reclassified out of AOCI, after-tax 50 45
Total tax effect (18) (15)
Prior service cost (benefit) | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Other Noninterest Expense (3) (4)
Net actuarial loss | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Other Noninterest Expense 71 64
Curtailment/settlement impact | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Other Noninterest Expense 0 0
Excluded component of fair value hedges    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax (1) 1
Excluded component of fair value hedges | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Subtotal, pretax (1) 1
Tax effect 0 0
Total amounts reclassified out of AOCI, after-tax (1) 1
Long-duration insurance contracts    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax 0 0
Long-duration insurance contracts | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Subtotal, pretax 0 0
Tax effect 0 0
Total amounts reclassified out of AOCI, after-tax 0 0
Foreign currency translation adjustment (CTA)    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Total amounts reclassified out of AOCI, after-tax (4) 12
Foreign currency translation adjustment (CTA) | (Gain) loss reclassified from AOCI    
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)    
Subtotal, pretax (4) 12
Tax effect 0 0
Total amounts reclassified out of AOCI, after-tax $ (4) $ 12