INVESTMENTS (Details - Gross realized gains and gross realized losses from sales or maturities of available for sale securities) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of available for sale securities sold	$ 3,100	$ 4,500	$ 17,000	$ 17,300
Net realized capital gains (losses)	175	128	538	184
Fortitude
Schedule of Available-for-sale Securities [Line Items]
Net realized capital gains (losses)	147		269
Fixed maturity securities
Schedule of Available-for-sale Securities [Line Items]
Gross Realized Gains	258	198	1,179	464
Gross Realized Losses	$ 83	$ 70	$ 641	$ 280

This element represents the aggregate fair value of Available-for-sale securities sold during the reporting period.

No definition available.

Name:	aig_AvailableForSaleSecuritiesSoldFairValue
Namespace Prefix:	aig_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossRealizedGains
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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