Fair Value of Financial Instruments (By Balance Sheet Grouping) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
AFS securities:
Derivative Assets	$ 2,652	$ 3,151
Cash and Cash Equivalents, Fair Value Disclosure	4,230	4,510
Future contract benefits:
GLB embedded derivative reserves	(909)	(2,217)
Carrying Value [Member]
AFS securities:
Available For Sale Securities Fixed Maturity Fair Value Disclosure	82,036	75,433
Available For Sale Securities Vie Fixed Maturity Fair Value Disclosure	708	700
Available For Sale Securities Equity Fair Value Disclosure	157	139
Trading Securities, Fair Value Disclosure	2,554	2,675
Mortgage Loans On Real Estate Fair Value Disclosure	7,029	6,942
Derivative Assets	2,652	3,151
Other Investments Fair Value Disclosure	1,098	1,069
Cash and Cash Equivalents, Fair Value Disclosure	4,230	4,510
Separate Account Assets Fair Value Disclosure	95,373	83,477
Future contract benefits:
Indexed annuity contracts	(732)	(399)
Other contract holder funds:
Remaining guaranteed interest and similar contracts	(867)	(1,114)
Account value of certain investment contracts	(28,540)	(27,468)
Short-term debt	(200)	(300)
Long-term debt	(5,439)	(5,391)
Reinsurance related embedded derivatives	(215)	(168)
Variable interest entities' liabilities - derivative instruments	(128)	(291)
Other liabilities:
Credit default swaps	(11)	(16)
Benefit Plans' Assets	1,456	1,345
Fair Value [Member]
AFS securities:
Available For Sale Securities Fixed Maturity Fair Value Disclosure	82,036	75,433
Available For Sale Securities Vie Fixed Maturity Fair Value Disclosure	708	700
Available For Sale Securities Equity Fair Value Disclosure	157	139
Trading Securities, Fair Value Disclosure	2,554	2,675
Mortgage Loans On Real Estate Fair Value Disclosure	7,704	7,608
Derivative Assets	2,652	3,151
Other Investments Fair Value Disclosure	1,098	1,069
Cash and Cash Equivalents, Fair Value Disclosure	4,230	4,510
Separate Account Assets Fair Value Disclosure	95,373	83,477
Future contract benefits:
Indexed annuity contracts	(732)	(399)
GLB embedded derivative reserves	(909)	(2,217)
Other contract holder funds:
Remaining guaranteed interest and similar contracts	(867)	(1,114)
Account value of certain investment contracts	(32,688)	(30,812)
Short-term debt	(204)	(309)
Long-term debt	(5,824)	(5,345)
Reinsurance related embedded derivatives	(215)	(168)
Variable interest entities' liabilities - derivative instruments	(128)	(291)
Other liabilities:
Credit default swaps	(11)	(16)
Benefit Plans' Assets	$ 1,456	$ 1,345