| Document and Entity Information | Apr. 20, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | American National Group Inc |
| Amendment Flag | false |
| Entity Central Index Key | 0001801075 |
| Document Type | 8-K |
| Document Period End Date | Apr. 20, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39369 |
| Entity Tax Identification Number | 30-1221711 |
| Entity Address, Address Line One | One Moody Plaza |
| Entity Address, City or Town | Galveston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77550-7999 |
| City Area Code | (409) |
| Local Phone Number | 763-4661 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, Par Value $0.01 |
| Trading Symbol | ANAT |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
