Reinsurance - Reinsurance Recoverables (Details) $ in Millions	Jun. 30, 2015 USD ($) Reinsurers	Dec. 31, 2014 USD ($)
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 7,021	$ 7,080
Reserve netted against reinsurance recoverables	$ 4
Minimum [Member] | Standard Poors A Rating Or Better [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverable percent secured	90.00%
Guaranteed Minimum Income Benefit [Member]
Ceded Credit Risk [Line Items]
Number of external reinsurers	3	3
Berkshire Hathway Life Insurance Company Of Nebraska [Member] | Guaranteed Minimum Death Benefits [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 1,105	$ 1,147
Berkshire Hathway Life Insurance Company Of Nebraska [Member] | Guaranteed Minimum Death Benefits [Member] | Ceded Credit Risk Secured [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables percentage of total	100.00%
The Lincoln National Life Insurance Company And Lincoln Life And Annuity Of New York [Member] | Individual Life Insurance And Annuity [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 3,748	3,817
Prudential Retirement Insurance And Annuity Company [Member] | Retirement Benefits [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 1,050	1,092
Prudential Retirement Insurance And Annuity Company [Member] | Retirement Benefits [Member] | Ceded Credit Risk Secured [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables percentage of total	100.00%
Great American Life Insurance Company [Member] | Supplemental Benefits business (resulting from the acquistion) [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 326	336
Great American Life Insurance Company [Member] | Supplemental Benefits business (resulting from the acquistion) [Member] | Ceded Credit Risk Secured [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables percentage of total	100.00%
Other Retrocessionaires [Member] | Guaranteed Minimum Death Benefits [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 38	39
Other Retrocessionaires [Member] | Guaranteed Minimum Death Benefits [Member] | Ceded Credit Risk Secured [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables percentage of total	99.00%
Other Retrocessionaires [Member] | Ongoing Operations [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 667	561
Maximum reinsurance recoverable from a single reinsurer	277
Other Retrocessionaires [Member] | Ongoing Operations [Member] | Maximum [Member]
Ceded Credit Risk [Line Items]
Minimum reinsurance recoverable balance from a single reinsurer	$ 1
Other Retrocessionaires [Member] | Ongoing Operations [Member] | Minimum [Member]
Ceded Credit Risk [Line Items]
Number of external reinsurers | Reinsurers	80
Other Retrocessionaires [Member] | Ongoing Operations [Member] | Ceded Credit Risk Secured [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables percentage of total	9.00%
Other Retrocessionaires [Member] | Other run-off reinsurance [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 87	$ 88
Other Retrocessionaires [Member] | Other run-off reinsurance [Member] | Ceded Credit Risk Secured [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables percentage of total	99.00%