Consolidated Balance Sheets Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Debt Securities, Amortized Cost Basis		$ 56,965	$ 55,362
Variable Interest Entity, Consolidated, Carrying Amount, Assets		166	246
Available-for-sale Equity Securities, Amortized Cost Basis		1,135	1,027
Available-for-sale Securities, Equity Securities		1,121	1,047
Trading Securities, Equity	[1]	11	11
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	[2]	$ 12	$ 6
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Common Stock, Shares Authorized		1,500,000,000	1,500,000,000
Common Stock, Shares, Issued		490,923,222	490,923,222
Treasury Stock, Shares		89,102,038	66,507,690
Variable Interest Entity, Primary Beneficiary [Member]
Available-for-sale Equity Securities, Amortized Cost Basis		$ 1	$ 0
Equity Securities [Member]
Available-for-sale Equity Securities, Amortized Cost Basis		842	676
Available-for-sale Securities, Equity Securities		839	699
Equity Securities [Member]
Available-for-sale Equity Securities, Amortized Cost Basis		293	351
Available-for-sale Securities, Equity Securities		282	348
Fixed Maturities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		150	218
Short-term Investments [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		3	16
Cash [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		10	9
Commercial Loan [Member]
Allowance for Loan and Lease Losses, Real Estate		23	18
Limited Partnerships and Other Alternative Investments [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets		2	3
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	[2]	$ 0	$ 1

[1] [1]Included in other investments on the Consolidated Balance Sheets.

[2] Included in other liabilities in the Company’s Consolidated Balance Sheets.