Schedule I - Summary of Investments (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	$ 21,134
Amount at which shown in the Consolidated Balance Sheet	22,365
Debt Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	15,273
Fair value	16,486
Amount at which shown in the Consolidated Balance Sheet	16,486
US Government and Government Agencies and Authorities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	640
Fair value	880
Amount at which shown in the Consolidated Balance Sheet	880
State and local government [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	1,983
Fair value	2,144
Amount at which shown in the Consolidated Balance Sheet	2,144
Foreign Government Debt [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	1,392
Fair value	1,444
Amount at which shown in the Consolidated Balance Sheet	1,444
Public Utility, Bonds [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	90
Fair value	92
Amount at which shown in the Consolidated Balance Sheet	92
All Other Corporate Bonds [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	10,176
Fair value	10,849
Amount at which shown in the Consolidated Balance Sheet	10,849
Federal agency mortgage-backed [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	77
Fair value	76
Amount at which shown in the Consolidated Balance Sheet	76
Commercial Mortgage Loans [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	76
Fair value	77
Amount at which shown in the Consolidated Balance Sheet	77
Other asset and mortgage-backed securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	799
Fair value	884
Amount at which shown in the Consolidated Balance Sheet	884
Mandatorily Redeemable Preferred Stock [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	40
Fair value	40
Amount at which shown in the Consolidated Balance Sheet	40
Equity Securities, Investment Summary [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	146
Fair value	141
Amount at which shown in the Consolidated Balance Sheet	141
Industrial, Miscellaneous, and All Others [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	57
Fair value	64
Amount at which shown in the Consolidated Balance Sheet	64
Nonredeemable Preferred Stock [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	89
Fair value	77
Amount at which shown in the Consolidated Balance Sheet	77
Mortgage Loans on Real Estate [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	2,252
Amount at which shown in the Consolidated Balance Sheet	2,252
Policy Loans [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	1,485
Amount at which shown in the Consolidated Balance Sheet	1,485
Real Estate Entities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	97
Amount at which shown in the Consolidated Balance Sheet	97
Other Long Term Investments [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	1,250
Amount at which shown in the Consolidated Balance Sheet	1,273
Short-term Investments [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	631
Amount at which shown in the Consolidated Balance Sheet	$ 631