| Document and Entity Information | Aug. 28, 2019 |
| Cover [Abstract] | |
| Amendment Flag | true |
| Entity Central Index Key | 0000904163 |
| Document Type | 8-K/A |
| Document Period End Date | Aug. 28, 2019 |
| Entity Registrant Name | AMERICAN NATIONAL INSURANCE CO |
| Entity Incorporation, State or Country Code | TX |
| Entity File Number | 001-34280 |
| Entity Tax Identification Number | 74-0484030 |
| 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 |
| Title of 12(b) Security | Common Stock, Par Value $1.00 |
| Trading Symbol | ANAT |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Description | This Current Report on Form 8-K/A amends the Current Report on Form 8-K that was filed with the Securities and Exchange Commission (the “SEC”) on August 29, 2019 (the “Original Form 8-K”) by American National Insurance Company (the “Company”). |
