Financial Condition and Net Income on a Statutory Basis - Significant Subsidiaries (Statutory Accounting Practices Disclosure) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
RGA Reinsurance [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	$ 3,253	$ 3,206
Statutory Accounting Practices, Statutory Net Income Amount	122	157	$ 5
RGA Canada [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	1,447	1,303
Statutory Accounting Practices, Statutory Net Income Amount	36	38	(7)
RGA Barbados [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	2,200	1,621
Statutory Accounting Practices, Statutory Net Income Amount	275	133	(143)
RGA Atlantic [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	781	718
Statutory Accounting Practices, Statutory Net Income Amount	20	21	44
RGA International Reinsurance Company dac [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	447	561
Statutory Accounting Practices, Statutory Net Income Amount	(43)	(22)	0
RGA Americas [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	2,307	2,437
Statutory Accounting Practices, Statutory Net Income Amount	(3)	483	(332)
Other Reinsurance Subsidiaries [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	420	93
Statutory Accounting Practices, Statutory Net Income Amount	104	(883)	90
RGA Worldwide Reinsurance Company
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	688	641
Statutory Accounting Practices, Statutory Net Income Amount	41	64	8
RGA Global Reinsurance Company
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	445	456
Statutory Accounting Practices, Statutory Net Income Amount	14	52	(67)
RGA Life and Annuity Insurance Company
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	5,466	4,304
Statutory Accounting Practices, Statutory Net Income Amount	$ 686	$ 657	$ (441)