Number of shares granted to non-employee directors during the period.

No definition available.

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period as part of the Company's Repurchase Agreement. Recorded using the cost method.

+ References

No definition available.

+ Details

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Namespace Prefix:	rga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of treasury shares (units) reissued during the period, excluding reissuance of shares (units) held in treasury used to satisfy equity-based compensation obligations exercised by the holders of such rights. Upon reissuance of shares (units) from treasury, either the common or preferred stock (unit) reissued is outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Stock Transactions (Narrative) (Details) (USD $)	12 Months Ended
Stock Transactions (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Jan. 22, 2015
Stock Transactions [Line Items]
Treasury Stock, Shares, Acquired	2,530,608us-gaap_TreasuryStockSharesAcquired	4,151,312us-gaap_TreasuryStockSharesAcquired
Treasury Stock Acquired, Average Cost Per Share	$ 78.22
Shares Granted To Non Employee Directors	13,800rga_SharesGrantedToNonEmployeeDirectors
Stock Repurchase Program, Authorized Amount	$ 300,000,000.0		$ 100,000,000.0	$ 100,000,000.0	$ 200,000,000.0
Treasury Stock Value Acquired Cost Method Repurchase Agreement	197,700,000	261,300,000
Incentive Award Tax Settlement [Member]
Stock Transactions [Line Items]
Stock Issued During Period, Shares, Treasury Stock Reissued	584,915
Treasury Stock, Shares, Acquired	49,564
Subsequent Event [Member]
Stock Transactions [Line Items]
Stock Repurchase Program, Authorized Amount						$ 300,000,000.0