Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Share data	Jun. 30, 2011	Dec. 31, 2010
Stockholders' Equity
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	34,595,317	34,595,317
Common stock, shares outstanding	34,595,317	34,595,317
Investments:
Amortized cost of fixed maturity securities available-for-sale	$ 45,548	$ 44,132
Cost of equity securities available-for-sale	293	427
Mortgage loans:
Valuation allowances for held-for-investment	70	87
Mortgage loans, at estimated fair value, relating to variable interest entities	12,645	12,730
Accrued investment income relating to variable interest entities	534	559
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	7,410	7,568
Other liabilities relating to variable interest entities	4,357	4,503
Variable Interest, Held by Entity [Member]
Mortgage loans:
Mortgage loans, at estimated fair value, relating to variable interest entities	6,697	6,840
Accrued investment income relating to variable interest entities	32	31
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	6,617	6,773
Other liabilities relating to variable interest entities	$ 31	$ 31