INVESTMENTS (Details - Securities available for sale in a loss position) - Bonds available for sale $ in Millions	Sep. 30, 2021 USD ($) security	Dec. 31, 2020 USD ($) security
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	$ 48,420	$ 24,504
Gross Unrealized Losses, Less than 12 Months	1,197	576
Fair Value, 12 Months or More	8,202	5,314
Gross Unrealized Losses, 12 Months or More	502	192
Fair Value, Total	56,622	29,818
Gross Unrealized Losses, Total	$ 1,699	$ 768
Number of securities in an unrealized loss position \| security	11,524	5,105
Number of individual securities in continuous unrealized loss position for longer than twelve months \| security	1,591	949
U.S. government and government sponsored entities
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	$ 1,340	$ 649
Gross Unrealized Losses, Less than 12 Months	10	17
Fair Value, 12 Months or More	287	0
Gross Unrealized Losses, 12 Months or More	7	0
Fair Value, Total	1,627	649
Gross Unrealized Losses, Total	17	17
Obligations of states, municipalities and political subdivisions
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	702	267
Gross Unrealized Losses, Less than 12 Months	11	4
Fair Value, 12 Months or More	84	78
Gross Unrealized Losses, 12 Months or More	4	3
Fair Value, Total	786	345
Gross Unrealized Losses, Total	15	7
Non-U.S. governments
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	4,250	1,287
Gross Unrealized Losses, Less than 12 Months	123	28
Fair Value, 12 Months or More	604	262
Gross Unrealized Losses, 12 Months or More	100	33
Fair Value, Total	4,854	1,549
Gross Unrealized Losses, Total	223	61
Corporate debt
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	30,283	11,715
Gross Unrealized Losses, Less than 12 Months	915	348
Fair Value, 12 Months or More	5,058	1,283
Gross Unrealized Losses, 12 Months or More	317	81
Fair Value, Total	35,341	12,998
Gross Unrealized Losses, Total	1,232	429
Residential mortgage-backed securities (RMBS)
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	5,605	3,486
Gross Unrealized Losses, Less than 12 Months	74	40
Fair Value, 12 Months or More	1,041	282
Gross Unrealized Losses, 12 Months or More	37	18
Fair Value, Total	6,646	3,768
Gross Unrealized Losses, Total	111	58
Commercial mortgage-backed securities (CMBS)
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	1,739	1,644
Gross Unrealized Losses, Less than 12 Months	29	58
Fair Value, 12 Months or More	294	346
Gross Unrealized Losses, 12 Months or More	16	12
Fair Value, Total	2,033	1,990
Gross Unrealized Losses, Total	45	70
Collateralized Debt Obligations/Asset-Backed Securities (CDO/ABS)
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Fair Value, Less than 12 Months	4,501	5,456
Gross Unrealized Losses, Less than 12 Months	35	81
Fair Value, 12 Months or More	834	3,063
Gross Unrealized Losses, 12 Months or More	21	45
Fair Value, Total	5,335	8,519
Gross Unrealized Losses, Total	$ 56	$ 126

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922890-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922888-210455

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922890-210455

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922888-210455

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_InvestmentTypeAxis=aig_BondsAvailableForSaleSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=aig_CollateralizedDebtObligationsAndAssetBackedSecuritiesSecuritizedLoansAndReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: