Investments (Schedule Of Impaired Mortgage Loans) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013 item	Mar. 31, 2012	Dec. 31, 2012 item
Information about impaired mortgage loans on real estate
Number of impaired mortgage loans on real estate	6		10
Principal balance of impaired mortgage loans on real estate	$ 46		$ 75
Valuation allowance associated with impaired mortgage loans on real estate	(8)		(21)
Carrying value of impaired mortgage loans on real estate	38		54
Average carrying value for impaired loans on real estate	46	64
Interest income recognized on impaired mortgage loans on real estate	1
Interest income collected on impaired mortgage loans on real estate	$ 1

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6873192&loc=d3e21338-158488

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