Fair value of securities as a percentage of amortized cost.

Name:	rga_FairValueOfSecuritiesSoldAsPercentageOfAmortizedCost
Namespace Prefix:	rga
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	rga_InvestmentNarrativeLineItems
Namespace Prefix:	rga
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	rga_LoansAndLeasesReceivableImpairedAverageInvestmentWithoutValuationAllowances
Namespace Prefix:	rga
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	rga_LoansAndLeasesReceivableImpairedAverageInvestmentWithValuationAllowances
Namespace Prefix:	rga
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	rga_MortgageLoanPercentOfCashAndInvestedAssets
Namespace Prefix:	rga
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage Of total Gross Unrealized Losses

+ Details

Name:	rga_PercentageOfTotalGrossUnrealizedLosses
Namespace Prefix:	rga
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

+ Details

Name:	rga_ProceedsFromSaleOfAvailableForSaleSecuritiesSoldAtLoss
Namespace Prefix:	rga
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 7
-Footnote 2

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 19

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 12
-Subparagraph b

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesFairValueDisclosure
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the amount of interest income on impaired and nonperforming loans that was recognized as income during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 114
-Paragraph 20

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 8
-Subparagraph j(ii)
-Subsection I

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 15
-Paragraph 40

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedInterestIncomeRecognized
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph g

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedNonperformingNonaccrualOfInterest
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Total amount of additions to mortgage loans other than new loans during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph c
-Subparagraph Schedule IV
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 29
-Article 12

+ Details

Name:	us-gaap_MortgageLoansOnRealEstateOtherAdditions
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Investments (Narrative) (USD $)	3 Months Ended		6 Months Ended
Investments (Narrative) (USD $)	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Investment Narrative
Proceeds From Sale Of Available For Sale Securities Sold At Loss	$ 135,000,000	$ 159,200,000	$ 331,600,000	$ 399,300,000
Fair Value Of Securities Sold As Percentage Of Amortized Cost	95.30%	96.60%	96.10%	96.60%
Mortgage Loan Percent Of Cash And Invested Assets	3.70%	3.80%	3.70%	3.80%
Loans And Leases Receivable Impaired Average Investment With Valuation Allowances	3,600,000	6,700,000	3,600,000	6,700,000
Loans And Leases Receivable Impaired Average Investment Without Valuation Allowances	2,300,000	3,100,000	2,300,000	3,100,000
Loans And Leases Receivable Impaired Nonperforming Nonaccrual Of Interest	13,000,000		13,000,000		15,600,000
Mortgage Loans On Real Estate Other Additions			37,800,000
Borrowed Securities [Member]
Investment Narrative
Available For Sale Securities Amortized Cost	150,000,000		150,000,000
Available For Sale Securities Fair Value Disclosure	150,700,000		150,700,000
Collateral Fixed Maturity Securities [Member]
Investment Narrative
Available For Sale Securities Amortized Cost	57,900,000		57,900,000		46,900,000
Available For Sale Securities Fair Value Disclosure	60,300,000		60,300,000		48,200,000
Canadian Province Of Ontario Securities [Member]
Investment Narrative
Available For Sale Securities Fair Value Disclosure	1,005,200,000		1,005,200,000		959,500,000
Canadian Province Of Quebec Securities [Member]
Investment Narrative
Available For Sale Securities Fair Value Disclosure	898,600,000		898,600,000		871,600,000
Investment Grade Securities [Member]
Investment Narrative
Percentage Of Total Gross Unrealized Losses	70.70%		70.70%		66.10%
Impaired Financing Receivable With Related Allowance Member
Investment Narrative
Loans And Leases Receivable Impaired Interest Income Recognized	200,000	0	500,000	0
Impaired Financing Receivable With No Related Allowance Member
Investment Narrative
Loans And Leases Receivable Impaired Interest Income Recognized	$ 100,000	$ 100,000	$ 100,000	$ 300,000