Investments (Schedule Of Investments In Partially-Owned Insurance Companies) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Investment [Line Items]
Carrying Value	$ 678	$ 662
Issued Share Capital	1,864	1,942
Huatai Group \| CHINA
Investment [Line Items]
Carrying Value	452	438
Issued Share Capital	$ 587	$ 616
Ownership Percentage	20.00%	20.00%
Huatai Life Insurance Company \| CHINA
Investment [Line Items]
Carrying Value	$ 106	$ 105
Issued Share Capital	$ 472	$ 495
Ownership Percentage	20.00%	20.00%
Freisenbruch-Meyer \| Bermuda
Investment [Line Items]
Carrying Value	$ 9	$ 9
Issued Share Capital	$ 0	$ 0
Ownership Percentage	40.00%	40.00%
Russian Reinsurance Company \| Russia
Investment [Line Items]
Carrying Value	$ 2	$ 2
Issued Share Capital	$ 4	$ 4
Ownership Percentage	23.00%	23.00%
ABR Reinsurance Capital Holdings Ltd. [Member] \| Bermuda
Investment [Line Items]
Carrying Value	$ 91	$ 93
Issued Share Capital	$ 774	$ 800
Ownership Percentage	12.00%	11.00%
Chubb Arabia Cooperative Insurance Company [Member] \| Saudi Arabia
Investment [Line Items]
Carrying Value	$ 18	$ 15
Issued Share Capital	$ 27	$ 27
Ownership Percentage	30.00%	30.00%

Line items represent reporting 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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 12
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
-Paragraph 1
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
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