| Pay vs Performance Disclosure | 2 Months Ended | 10 Months Ended | 12 Months Ended |
| Feb. 28, 2021 | Dec. 31, 2021 | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) |
| Pay vs Performance Disclosure [Table] | | | | | |
| Pay vs Performance [Table Text Block] | | | Summary Compensation Table Total for Peter Zaffino 1 ($) Summary 1 ($) Compensation 1,2,3 ($) Compensation 1,2,3 ($) Average 1 ($) Average Compensation 1,2,3 ($) Value of Initial Fixed $100 Investment 4 Accident Year Combined 5 (%) Year TSR ($) Peer Group TSR ($) Net Income 2022 75,314,199 — 90,844,101 — 9,077,342 12,293,363 134.37 147.35 11,275 88.7 2021 21,905,220 13,969,537 52,445,392 45,269,700 10,476,911 20,741,560 118.13 125.52 9,923 91.0 2020 — 18,810,374 — 14,041,042 12,890,475 10,890,203 76.75 102.61 (5,829) 94.1 | | |
| Company Selected Measure Name | | | AYCR, ex-CATs | | |
| Named Executive Officers, Footnote [Text Block] | | | Peter Zaffino has been our PEO since March 2021. Brian Duperreault was our PEO prior to March 2021. The individuals comprising the Non-PEO named executive officers for each year presented are listed below. 2020 2021 2022 Peter Zaffino Mark Lyons Shane Fitzsimons Mark Lyons Lucy Fato Lucy Fato Lucy Fato David McElroy David McElroy Doug Dachille Kevin Hogan Kevin Hogan Doug Dachille | | |
| Peer Group Issuers, Footnote [Text Block] | | | The Peer Group TSR set forth in this table utilizes the S&P 500 Property & Casualty Insurance Index (S&P 500 Property & Casualty Insurance Index), which we also utilize in the stock performance graph required by Item 201(e) of Regulation S-K included in AIG's Annual Report on Form 10-K for the year ended December 31, 2022. The comparison assumes $100 was invested for the period starting December 31, 2019, through the end of the last listed year, in the Company and in the S&P 500 Property & Casualty Insurance Index, respectively. Historical stock performance is not necessarily indicative of future stock performance. As described above, AIG’s business included its Life and Retirement business until the separation of that business, which AIG rebranded as Corebridge upon its IPO. AIG continues to hold approximately 78 percent of Corebridge common stock. | | |
| Adjustment To PEO Compensation, Footnote [Text Block] | | | Compensation Actually Paid reflects the exclusions and inclusions of certain amounts for the PEOs and the Non-PEO NEOs as set forth below. Equity values are calculated in accordance with FASB ASC Topic 718. Amounts in the Exclusion of Stock Awards and Option Awards column are the totals from the Stock Awards and Option Awards columns set forth in the applicable Summary Compensation Table. Year Summary Compensation Exclusion of Change in Pension Value for Peter Zaffino Exclusion of Stock Inclusion of Pension Service Cost for Peter Zaffino ($) Inclusion of Compensation 2022 75,314,199 0 (67,647,879) 0 83,177,781 90,844,101 2021 21,905,220 0 (12,254,950) 0 42,795,122 52,445,392 Year Summary Compensation Exclusion of Change in Pension Value for Brian Duperreault Exclusion of Stock Inclusion of Pension Service Cost for Brian Duperreault ($) Inclusion of Compensation 2021 13,969,537 0 (11,234,009) 0 42,534,172 45,269,700 2020 18,810,374 (184,309) (12,285,323) 0 7,700,300 14,041,042 Year Average Summary Compensation Table Total for Non-PEO NEOs ($) Average Exclusion of Change in Pension Value for Non-PEO NEOs Average Exclusion of Stock Awards and Option Awards for Non-PEO NEOs Average Inclusion of Pension Service Cost for Non-PEO NEOs ($) Average Inclusion of Equity Values for Non-PEO NEOs ($) Average Compensation Actually Paid to Non-PEO NEOs ($) 2022 9,077,342 0 (4,640,489) 0 7,856,510 12,293,363 2021 10,476,911 (175) (4,735,671) 0 15,000,495 20,741,560 2020 12,890,475 (273) (8,248,843) 0 6,248,844 10,890,203 The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables. Please note that any columns included in the calculation of Compensation Actually Paid that contain a “0” did not have an amount in that category for that year. Year Year-End Fair Value Change in Fair Value Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Peter Zaffino ($) Change in Fair Value Fair Value at Last Day Total - Inclusion of 2022 69,711,054 13,466,727 — 0 0 83,177,781 2021 16,908,143 25,886,979 — 0 0 42,795,122 Year Year-End Fair Value Change in Fair Value Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Brian Duperreault ($) Change in Fair Value Fair Value at Last Day Total - Inclusion of 2021 17,143,842 25,390,330 — 0 0 42,534,172 2020 15,007,466 (6,882,257) — (424,909) 0 7,700,300 Year Average Year-End Fair Average Change in Average Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Non-PEO NEOs ($) Average Change Average Fair Value Total - Average 2022 5,173,501 2,675,346 — 7,663 0 7,856,510 2021 7,160,255 7,733,168 — 107,072 0 15,000,495 2020 9,165,423 (2,850,295) — 290,506 (356,790) 6,248,844 | | |
| Non-PEO NEO Average Total Compensation Amount | | | $ 9,077,342 | $ 10,476,911 | $ 12,890,475 |
| Non-PEO NEO Average Compensation Actually Paid Amount | | | $ 12,293,363 | 20,741,560 | 10,890,203 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | | | Compensation Actually Paid reflects the exclusions and inclusions of certain amounts for the PEOs and the Non-PEO NEOs as set forth below. Equity values are calculated in accordance with FASB ASC Topic 718. Amounts in the Exclusion of Stock Awards and Option Awards column are the totals from the Stock Awards and Option Awards columns set forth in the applicable Summary Compensation Table. Year Summary Compensation Exclusion of Change in Pension Value for Peter Zaffino Exclusion of Stock Inclusion of Pension Service Cost for Peter Zaffino ($) Inclusion of Compensation 2022 75,314,199 0 (67,647,879) 0 83,177,781 90,844,101 2021 21,905,220 0 (12,254,950) 0 42,795,122 52,445,392 Year Summary Compensation Exclusion of Change in Pension Value for Brian Duperreault Exclusion of Stock Inclusion of Pension Service Cost for Brian Duperreault ($) Inclusion of Compensation 2021 13,969,537 0 (11,234,009) 0 42,534,172 45,269,700 2020 18,810,374 (184,309) (12,285,323) 0 7,700,300 14,041,042 Year Average Summary Compensation Table Total for Non-PEO NEOs ($) Average Exclusion of Change in Pension Value for Non-PEO NEOs Average Exclusion of Stock Awards and Option Awards for Non-PEO NEOs Average Inclusion of Pension Service Cost for Non-PEO NEOs ($) Average Inclusion of Equity Values for Non-PEO NEOs ($) Average Compensation Actually Paid to Non-PEO NEOs ($) 2022 9,077,342 0 (4,640,489) 0 7,856,510 12,293,363 2021 10,476,911 (175) (4,735,671) 0 15,000,495 20,741,560 2020 12,890,475 (273) (8,248,843) 0 6,248,844 10,890,203 The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables. Please note that any columns included in the calculation of Compensation Actually Paid that contain a “0” did not have an amount in that category for that year. Year Year-End Fair Value Change in Fair Value Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Peter Zaffino ($) Change in Fair Value Fair Value at Last Day Total - Inclusion of 2022 69,711,054 13,466,727 — 0 0 83,177,781 2021 16,908,143 25,886,979 — 0 0 42,795,122 Year Year-End Fair Value Change in Fair Value Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Brian Duperreault ($) Change in Fair Value Fair Value at Last Day Total - Inclusion of 2021 17,143,842 25,390,330 — 0 0 42,534,172 2020 15,007,466 (6,882,257) — (424,909) 0 7,700,300 Year Average Year-End Fair Average Change in Average Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Non-PEO NEOs ($) Average Change Average Fair Value Total - Average 2022 5,173,501 2,675,346 — 7,663 0 7,856,510 2021 7,160,255 7,733,168 — 107,072 0 15,000,495 2020 9,165,423 (2,850,295) — 290,506 (356,790) 6,248,844 | | |
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | | | Relationship Between PEOs and Other NEO Compensation Actually Paid and Company Total Shareholder Return The following chart sets forth the relationship between Compensation Actually Paid to our PEOs, the average of Compensation Actually Paid to our other NEOs, and the Company’s cumulative TSR over the three most recently completed fiscal years. PEO and Average NEO Compensation Actually Paid Versus AIG, Inc. TSR Fiscal Year Peter Zaffino Compensation Actually Paid Brian Duperreault Compensation Actually Paid Average NEO Compensation Actually Paid AIG, Inc. TSR | | |
| Compensation Actually Paid vs. Net Income [Text Block] | | | Relationship Between PEOs and Other NEO Compensation Actually Paid and Net Income The following chart sets forth the relationship between Compensation Actually Paid to our PEOs, the average of Compensation Actually Paid to our other NEOs, and our Net Income during the three most recently completed fiscal years. PEO and Average NEO Compensation Actually Paid Versus AIG, Inc. Net Income Fiscal Year Peter Zaffino Compensation Actually Paid Brian Duperreault Compensation Actually Paid Average NEO Compensation Actually Paid AIG, Inc. Net Income | | |
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | | | Relationship Between PEOs and Other NEO Compensation Actually Paid and Accident Year Combined Ratio, ex-CATs * The following chart sets forth the relationship between Compensation Actually Paid to our PEOs, the average of Compensation Actually Paid to our other NEOs, and our AYCR, ex-CATs*, during the three most recently completed fiscal years. PEO and Average NEO Compensation Actually Paid Versus AIG, Inc. Accident Year Combined Ratio, ex-CATs* Fiscal Year Peter Zaffino Compensation Actually Paid Brian Duperreault Compensation Actually Paid Average NEO Compensation Actually Paid Accident Year Combined Ratio, ex-CATs* * We make adjustments to U.S. GAAP financial measures for purposes of this performance metric. See Appendix A for an explanation of how this metric is calculated from our audited financial statements. | | |
| Total Shareholder Return Vs Peer Group [Text Block] | | | Relationship Between Company TSR and Peer Group TSR The following chart compares our cumulative TSR over the three most recently completed fiscal years to that of the S&P 500 Property & Casualty Insurance Index over the same period. Comparison of Cumulative TSR of AIG, Inc. and S&P 500 Property & Casualty Insurance Index (FYE 2019 Indexed to $100) AIG, Inc. TSR S&P 500 Property & Casualty Insurance Index TSR | | |
| Tabular List [Table Text Block] | | | Accident Year Combined Ratio, ex-CATs* Diluted Normalized Adjusted After-tax Income Attributable to AIG Common Shareholders Per Share* Relative Tangible Book Value Per Common Share* Growth AIG 200 Net GOE Exit Run-rate Savings ex Corebridge* Relative Total Shareholder Return | | |
| Total Shareholder Return Amount | | | $ 134.37 | 118.13 | 76.75 |
| Peer Group Total Shareholder Return Amount | | | 147.35 | 125.52 | 102.61 |
| Net Income (Loss) | | | $ 11,275,000,000 | $ 9,923,000,000 | $ (5,829,000,000) |
| Company Selected Measure Amount | | | 88.7 | 91 | 94.1 |
| PEO Name | Brian Duperreault | Peter Zaffino | Peter Zaffino | | Brian Duperreault |
| Additional 402(v) Disclosure [Text Block] | | | The amounts shown for Compensation Actually Paid have been calculated in accordance with Item 402(v) of Regulation S-K and do not reflect compensation actually earned, realized, or received by the Company’s NEOs. These amounts reflect the Summary Compensation Table Total with certain adjustments as described in footnote 3 below. In connection with AIG’s separation of its Life and Retirement business, AIG rebranded the business as Corebridge and the IPO of Corebridge was completed on September 19, 2022. AIG continues to own approximately 78 percent of Corebridge common stock. Mr. Hogan became an executive officer of Corebridge as well. At that time, Mr. Hogan’s outstanding and unvested RSUs denominated in AIG common stock were converted to unvested RSUs denominated in Corebridge common stock. As a result, the RSUs included in the table above were valued using the stock price of Corebridge as of December 31, 2022.Compensation Actually Paid reflects the exclusions and inclusions of certain amounts for the PEOs and the Non-PEO NEOs as set forth below. Equity values are calculated in accordance with FASB ASC Topic 718. Amounts in the Exclusion of Stock Awards and Option Awards column are the totals from the Stock Awards and Option Awards columns set forth in the applicable Summary Compensation Table. | | |
| Measure [Axis]: 1 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Accident Year Combined Ratio, ex-CATs* | | |
| Non-GAAP Measure Description [Text Block] | | | We determined AYCR, ex-CATs to be the most important financial performance measure used to link Company performance to Compensation Actually Paid to our PEO and Non-PEO NEOs in 2022. We make adjustments to U.S. GAAP financial measures for purposes of this performance metric. See Appendix A for an explanation of how this metric is calculated from our audited financial statements. | | |
| Measure [Axis]: 2 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Diluted Normalized Adjusted After-tax Income Attributable to AIG Common Shareholders Per Share* | | |
| Measure [Axis]: 3 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Relative Tangible Book Value Per Common Share* Growth | | |
| Measure [Axis]: 4 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | AIG 200 Net GOE Exit Run-rate Savings ex Corebridge* | | |
| Measure [Axis]: 5 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Relative Total Shareholder Return | | |
| Zaffino [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| PEO Total Compensation Amount | | | $ 75,314,199 | $ 21,905,220 | |
| PEO Actually Paid Compensation Amount | | | 90,844,101 | 52,445,392 | |
| Duperreault [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| PEO Total Compensation Amount | | | | 13,969,537 | $ 18,810,374 |
| PEO Actually Paid Compensation Amount | | | | 45,269,700 | 14,041,042 |
| PEO [Member] | Zaffino [Member] | Exclusion Of Change In Pension Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 0 | 0 | |
| PEO [Member] | Zaffino [Member] | Exclusion of Stock Awards and Option Awards [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (67,647,879) | (12,254,950) | |
| PEO [Member] | Zaffino [Member] | Inclusion Of Pension Service Cost [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 0 | 0 | |
| PEO [Member] | Zaffino [Member] | Inclusion Of Equity Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 83,177,781 | 42,795,122 | |
| PEO [Member] | Zaffino [Member] | Equity Awards Granted During the Year, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 69,711,054 | 16,908,143 | |
| PEO [Member] | Zaffino [Member] | Equity Awards Granted in Prior Years, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 13,466,727 | 25,886,979 | |
| PEO [Member] | Zaffino [Member] | Equity Awards Granted During the Year, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 0 | 0 | |
| PEO [Member] | Zaffino [Member] | Equity Awards Granted in Prior Years, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 0 | 0 | |
| PEO [Member] | Zaffino [Member] | Equity Awards Forfeited [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 0 | 0 | |
| PEO [Member] | Zaffino [Member] | Equity Awards Adjustments [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 83,177,781 | 42,795,122 | |
| PEO [Member] | Duperreault [Member] | Exclusion Of Change In Pension Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 0 | (184,309) |
| PEO [Member] | Duperreault [Member] | Exclusion of Stock Awards and Option Awards [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | (11,234,009) | (12,285,323) |
| PEO [Member] | Duperreault [Member] | Inclusion Of Pension Service Cost [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 0 | 0 |
| PEO [Member] | Duperreault [Member] | Inclusion Of Equity Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 42,534,172 | 7,700,300 |
| PEO [Member] | Duperreault [Member] | Equity Awards Granted During the Year, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | | 17,143,842 | 15,007,466 |
| PEO [Member] | Duperreault [Member] | Equity Awards Granted in Prior Years, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | | 25,390,330 | (6,882,257) |
| PEO [Member] | Duperreault [Member] | Equity Awards Granted During the Year, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | | 0 | 0 |
| PEO [Member] | Duperreault [Member] | Equity Awards Granted in Prior Years, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | | 0 | (424,909) |
| PEO [Member] | Duperreault [Member] | Equity Awards Forfeited [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | | 0 | 0 |
| PEO [Member] | Duperreault [Member] | Equity Awards Adjustments [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 42,534,172 | 7,700,300 |
| Non-PEO NEO [Member] | Exclusion Of Change In Pension Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 0 | (175) | (273) |
| Non-PEO NEO [Member] | Exclusion of Stock Awards and Option Awards [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (4,640,489) | (4,735,671) | (8,248,843) |
| Non-PEO NEO [Member] | Inclusion Of Pension Service Cost [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Inclusion Of Equity Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 7,856,510 | 15,000,495 | 6,248,844 |
| Non-PEO NEO [Member] | Equity Awards Granted During the Year, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 5,173,501 | 7,160,255 | 9,165,423 |
| Non-PEO NEO [Member] | Equity Awards Granted in Prior Years, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 2,675,346 | 7,733,168 | (2,850,295) |
| Non-PEO NEO [Member] | Equity Awards Granted During the Year, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Equity Awards Granted in Prior Years, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 7,663 | 107,072 | 290,506 |
| Non-PEO NEO [Member] | Equity Awards Forfeited [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount, Equity Awards | | | 0 | 0 | (356,790) |
| Non-PEO NEO [Member] | Equity Awards Adjustments [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | $ 7,856,510 | $ 15,000,495 | $ 6,248,844 |
