Name:	rga_ClaimsRecoverableFromRetrocessionairesPastDue
Namespace Prefix:	rga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of Embedded Derivative Asset.

No definition available.

Name:	rga_EmbeddedDerivativeAsset
Namespace Prefix:	rga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The maximum amount retained insurance coverage per individual life.

No definition available.

Name:	rga_MaximumLifeInsuranceRetentionPerIndividualLife
Namespace Prefix:	rga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Percentage of the Reinsurance Ceded Receivables and other total that is accounted for by 2 companies.

No definition available.

Name:	rga_ReinsuranceCededReceivablesPercentageTotal
Namespace Prefix:	rga_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Statutory financial reinsurance, as measured by pre-tax statutory surplus, provided to other insurance companies under financial reinsurance transactions to assist ceding companies in meeting applicable regulatory requirements.

No definition available.

Name:	rga_StatutoryFinancialReinsurance
Namespace Prefix:	rga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Name:	us-gaap_AssetsHeldInTrust
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_EffectsOfReinsuranceLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479838/944-20-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479616/944-310-45-5

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(6))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1