XML 51 R37.htm IDEA: XBRL DOCUMENT
v3.19.1

Equity (Common Stock Changes In Number of Shares Issued, Held In Treasury and Outstanding) (Details) - shares | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018 | Dec. 31, 2017
Class of Stock [Line Items] |  |  |  |  |
Common Stock, Shares, Issued |  | 79,137,758 |  | 79,137,758 |
Treasury Stock, Shares, Acquired |  | 300,000 |  |  |
Common Stock Issuable [Member] |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Common Stock, Shares, Issued |  | 79,137,758 | 79,137,758 | 79,137,758 | 79,137,758
Treasury Stock, Shares, Acquired |  | 0 |  |  |
Stock Based Compensation Shares | [1] | 0 | 0 |  |
Common Stock Held In Treasury [Member] |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Common Stock, Shares, Issued |  | 16,593,411 | 14,624,985 | 16,323,390 | 14,685,663
Treasury Stock, Shares, Acquired |  | 344,237 |  |  |
Stock Based Compensation Shares | [1] | (74,216) | (60,678) |  |
Common Stock Outstanding [Member] |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Common Stock, Shares, Issued |  | 62,544,347 | 64,512,773 | 62,814,368 | 64,452,095
Treasury Stock, Shares, Acquired |  | (344,237) |  |  |
Stock Based Compensation Shares | [1] | 74,216 | 60,678 |  |
[1] | Represents net shares issued from treasury pursuant to the Company’s equity-based compensation programs.

X
- Definition This item represents net shares issued from treasury pursuant to the Company's stock-based compensation program. + References No definition available. + Details
Name: | rga_StockBasedCompensationShares
Namespace Prefix: | rga_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares that have been repurchased during the period and are being held in treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_TreasuryStockSharesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=rga_CommonStockIssuableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=rga_CommonStockHeldInTreasuryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=rga_CommonStockOutstandingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |