XML 105 R81.htm IDEA: XBRL DOCUMENT
v3.25.3

INVESTMENTS - Overview (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | $ 246,227 |  | $ 246,227 |  | $ 226,876
Debt securities held-to-maturity (HTM) | 197,092 |  | 197,092 |  | 242,382
Marketable equity securities carried at fair value | 202 |  | 202 |  | 151
Non-marketable equity securities carried at fair value | 482 |  | 482 |  | 427
Non-marketable equity securities measured using the measurement alternative | 1,545 |  | 1,545 |  | 1,574
Non-marketable equity securities carried at cost | 5,184 |  | 5,184 |  | 5,247
Total investments | 450,732 |  | 450,732 |  | 476,657
Accrued interest receivable | 2,000 |  | 2,000 |  | 2,000
Interest and dividends on investments |  |  |  |  |
Taxable interest | 4,033 | $ 4,513 | 12,076 | $ 13,841 |
Interest exempt from U.S. federal income tax | 65 | 78 | 220 | 239 |
Dividend income | 72 | 92 | 246 | 273 |
Total interest and dividend income on investments | 4,170 | 4,683 | 12,542 | 14,353 |
Gross realized investments losses, excluding losses from other-than-temporary impairment |  |  |  |  |
Gross realized investment gains | 120 | 108 | 406 | 394 |
Gross realized investment losses | (15) | (36) | (42) | (184) |
Net realized gains on sales of investments | 105 | $ 72 | 364 | $ 210 |
Debt securities AFS |  |  |  |  |
Fair value | 246,227 |  | 246,227 |  | 226,876
Unallocated portfolio layer cumulative basis adjustments |  |  |  |  | (72)
Gross unrealized gains excluding the effect of unallocated portfolio cumulative basis adjustments | 161 |  | 161 |  | 35
Gross unrealized losses excluding the effect of unallocated portfolio cumulative basis adjustments | (555) |  | (555) |  | (1,129)
Mortgage-backed securities |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 36,648 |  | 36,648 |  | 29,931
Debt securities AFS |  |  |  |  |
Amortized cost | 37,335 |  | 37,335 |  | 30,835
Gross unrealized gains | 77 |  | 77 |  | 40
Gross unrealized losses | 764 |  | 764 |  | 944
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 36,648 |  | 36,648 |  | 29,931
U.S. government-sponsored agency guaranteed |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 35,673 |  | 35,673 |  | 29,306
Debt securities AFS |  |  |  |  |
Amortized cost | 36,360 |  | 36,360 |  | 30,208
Gross unrealized gains | 76 |  | 76 |  | 40
Gross unrealized losses | 763 |  | 763 |  | 942
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 35,673 |  | 35,673 |  | 29,306
Residential |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 974 |  | 974 |  | 624
Debt securities AFS |  |  |  |  |
Amortized cost | 974 |  | 974 |  | 626
Gross unrealized gains | 1 |  | 1 |  | 0
Gross unrealized losses | 1 |  | 1 |  | 2
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 974 |  | 974 |  | 624
Commercial |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 1 |  | 1 |  | 1
Debt securities AFS |  |  |  |  |
Amortized cost | 1 |  | 1 |  | 1
Gross unrealized gains | 0 |  | 0 |  | 0
Gross unrealized losses | 0 |  | 0 |  | 0
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 1 |  | 1 |  | 1
U.S. Treasury |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 37,018 |  | 37,018 |  | 52,379
Debt securities AFS |  |  |  |  |
Amortized cost | 37,063 |  | 37,063 |  | 52,630
Gross unrealized gains | 69 |  | 69 |  | 13
Gross unrealized losses | 114 |  | 114 |  | 264
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 37,018 |  | 37,018 |  | 52,379
U.S. Treasury and federal agency securities |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 37,018 |  | 37,018 |  | 52,379
Debt securities AFS |  |  |  |  |
Amortized cost | 37,063 |  | 37,063 |  | 52,630
Gross unrealized gains | 69 |  | 69 |  | 13
Gross unrealized losses | 114 |  | 114 |  | 264
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 37,018 |  | 37,018 |  | 52,379
State and municipal |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 1,691 |  | 1,691 |  | 1,658
Debt securities AFS |  |  |  |  |
Amortized cost | 1,758 |  | 1,758 |  | 1,749
Gross unrealized gains | 6 |  | 6 |  | 12
Gross unrealized losses | 73 |  | 73 |  | 103
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 1,691 |  | 1,691 |  | 1,658
Foreign government |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 161,641 |  | 161,641 |  | 133,359
Debt securities AFS |  |  |  |  |
Amortized cost | 161,199 |  | 161,199 |  | 134,002
Gross unrealized gains | 1,018 |  | 1,018 |  | 444
Gross unrealized losses | 576 |  | 576 |  | 1,087
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 161,641 |  | 161,641 |  | 133,359
Corporate |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 5,372 |  | 5,372 |  | 4,814
Debt securities AFS |  |  |  |  |
Amortized cost | 5,412 |  | 5,412 |  | 4,923
Gross unrealized gains | 34 |  | 34 |  | 19
Gross unrealized losses | 70 |  | 70 |  | 122
Allowance for credit losses | 4 |  | 4 |  | 6
Fair value | 5,372 |  | 5,372 |  | 4,814
Asset-backed securities |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 862 |  | 862 |  | 848
Debt securities AFS |  |  |  |  |
Amortized cost | 860 |  | 860 |  | 856
Gross unrealized gains | 4 |  | 4 |  | 3
Gross unrealized losses | 2 |  | 2 |  | 11
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 862 |  | 862 |  | 848
Other debt securities |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 2,995 |  | 2,995 |  | 3,887
Debt securities AFS |  |  |  |  |
Amortized cost | 2,994 |  | 2,994 |  | 3,887
Gross unrealized gains | 1 |  | 1 |  | 1
Gross unrealized losses | 0 |  | 0 |  | 1
Allowance for credit losses | 0 |  | 0 |  | 0
Fair value | 2,995 |  | 2,995 |  | 3,887
Debt securities AFS |  |  |  |  |
Investments |  |  |  |  |
Debt securities available-for-sale (AFS) | 246,227 |  | 246,227 |  | 226,876
Debt securities AFS |  |  |  |  |
Amortized cost | 246,621 |  | 246,621 |  | 228,882
Gross unrealized gains | 1,209 |  | 1,209 |  | 532
Gross unrealized losses | 1,599 |  | 1,599 |  | 2,532
Allowance for credit losses | 4 |  | 4 |  | 6
Fair value | 246,227 |  | 246,227 |  | 226,876
Unallocated portfolio layer cumulative basis adjustments | 300 |  | 300 |  | (200)
Fair value | Non-marketable securities measured using measurement alternative |  |  |  |  |
Investments |  |  |  |  |
Non-marketable equity securities measured using the measurement alternative | $ 34 |  | $ 34 |  | $ 23

X
- Definition Equity Securities, Carried At Fair Value, Nonmarketable + References No definition available. + Details
Name: | c_EquitySecuritiesCarriedAtFairValueNonmarketable
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the total gross realized gain included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains realized during the period from the sale of investments accounted for under the cost method of accounting and/or investments that are separately or otherwise not categorized as trading, available-for-sale, or held-to-maturity. + References No definition available. + Details
Name: | c_GrossRealizedGainOnMarketableSecuritiesAndCostMethodInvestmentsExcludingOtherThanTemporaryImpairmentsAndOtherInvestments
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gross Realized Loss on Marketable Securities and Cost Method Investments Excluding Other than Temporary Impairments and Other Investments + References No definition available. + Details
Name: | c_GrossRealizedLossonMarketableSecuritiesandCostMethodInvestmentsExcludingOtherthanTemporaryImpairmentsandOtherInvestments
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Hedged Asset, Fair Value Hedge, Portfolio Layer Method, Hedged Layer, Accumulated Gross Unrealized Gain, Before Tax, Cumulative Increase (Decrease) + References No definition available. + Details
Name: | c_HedgedAssetFairValueHedgePortfolioLayerMethodHedgedLayerAccumulatedGrossUnrealizedGainBeforeTaxCumulativeIncreaseDecrease
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Hedged Asset, Fair Value Hedge, Portfolio Layer Method, Hedged Layer, Accumulated Gross Unrealized Loss, Before Tax, Cumulative Increase (Decrease) + References No definition available. + Details
Name: | c_HedgedAssetFairValueHedgePortfolioLayerMethodHedgedLayerAccumulatedGrossUnrealizedLossBeforeTaxCumulativeIncreaseDecrease
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Interest and dividend income on all securities excluding trading securities. + References No definition available. + Details
Name: | c_InterestAndDividendIncomeSecuritiesExcludingTradingSecurities
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sum of the carrying amounts as of the balance sheet date of all investments, excluding trading account assets. + References No definition available. + Details
Name: | c_InvestmentsExcludingTradingSecuritiesExcludingAccruedInterest
Namespace Prefix: | c_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investments + References No definition available. + Details
Name: | c_InvestmentsLineItems
Namespace Prefix: | c_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 107 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-107 Reference 9: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 103 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-103 Reference 10: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 35 -Paragraph 54B -Publisher FASB -URI https://asc.fasb.org/1943274/2147482134/820-10-35-54B Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A + Details
Name: | us-gaap_AlternativeInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-5 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of operating dividend income on securities. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479168/946-830-55-10 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column E)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column E)(Footnote 4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480990/946-20-50-9 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 45 -Paragraph 39 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477346/946-830-45-39 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column E)(Footnote 6)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(1)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
Name: | us-gaap_DividendIncomeOperating
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482736/825-10-45-1A Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-10 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 10: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480078/944-80-55-14 Reference 11: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480078/944-80-55-9 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_EquitySecuritiesFvNiRealizedGainLossAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 321 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479536/321-10-50-3 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 325 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477974/942-325-45-1 + Details
Name: | us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, in portfolio layer hedging relationship. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 181 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-181 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4EEE -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4EEE + Details
Name: | us-gaap_HedgedAssetFairValueHedgeLastOfLayerCumulativeIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_InterestAndDividendIncomeSecuritiesByTaxableStatusAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities exempt from state, federal and other income tax. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph a -Publisher SEC Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph b -Subparagraph (1)(Instruction 4) -Publisher SEC + Details
Name: | us-gaap_InterestIncomeSecuritiesTaxExempt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities subject to state, federal and other income tax. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph a -Publisher SEC Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph b -Subparagraph (1)(Instruction 4) -Publisher SEC + Details
Name: | us-gaap_InterestIncomeSecuritiesTaxable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)(a)(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477802/946-310-45-1 + Details
Name: | us-gaap_InterestReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of realized gain (loss) on investment. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 + Details
Name: | us-gaap_RealizedInvestmentGainsLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=c_MortgageBackedSecuritiesIssuedByUSGovernmentCorporationsAndAgenciesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=c_NonMarketableSecuritiesMeasuredUsingMeasurementAlternativeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |