| Cover Document | Feb. 08, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Feb. 8, 2021 |
| Entity Registrant Name | REINSURANCE GROUP OF AMERICA, INCORPORATED |
| Entity File Number | 1-11848 |
| Entity Tax Identification Number | 43-1627032 |
| Entity Incorporation, State or Country Code | MO |
| Entity Address, Address Line One | 16600 Swingley Ridge Road |
| Entity Address, City or Town | Chesterfield |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63017 |
| City Area Code | 636 |
| Local Phone Number | 736-7000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000898174 |
| Cover Entity Listings - NEW YORK STOCK EXCHANGE, INC. [Member] | Feb. 08, 2021 |
| RGA [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.01 |
| Trading Symbol | RGA |
| Security Exchange Name | NYSE |
| RZA [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 6.20% Fixed-To-Floating Rate Subordinated Debentures due 2042 |
| Trading Symbol | RZA |
| Security Exchange Name | NYSE |
| RZB [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 5.75% Fixed-To-Floating Rate Subordinated Debentures due 2056 |
| Trading Symbol | RZB |
| Security Exchange Name | NYSE |
