Investments (Details 5) (USD $) In Millions	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Other-than-temporary impairments on investments
Net impairment losses recognized in earnings	$ 0	$ (4)	$ 0	$ (6)
Realized gains (losses) on investments
Net realized investment gains (losses)	39	(213)	188	(88)
Indemnity
Other-than-temporary impairments on investments
Total	0	(1)	0	(1)
Portion recognized in other comprehensive income	0	0	0	0
Net impairment losses recognized in earnings	0	(1)	0	(1)
Realized gains (losses) on investments
Net realized investment gains (losses)	6	(3)	7	2
Indemnity \| Fixed maturities
Available-for-sale securities:
Gross realized gains	2	1	2	3
Gross realized losses	0	0	0	0
Net realized gains	2	1	2	3
Other-than-temporary impairments on investments
Total	0	(1)	0	(1)
Indemnity \| Common stock
Trading securities:
Gross realized gains	1	0	2	1
Gross realized losses	0	0	0	0
Valuation adjustments	1	(4)	0	(2)
Net realized gains (losses)	2	(4)	2	(1)
Indemnity \| Equity securities
Available-for-sale securities:
Gross realized gains	2	1	3	1
Gross realized losses	0	(1)	0	(1)
Net realized gains	2	0	3	0
Other-than-temporary impairments on investments
Total	0	0	0	0
Exchange
Other-than-temporary impairments on investments
Total	0	(3)	0	(5)
Portion recognized in other comprehensive income	0	0	0	0
Net impairment losses recognized in earnings	0	(3)	0	(5)
Realized gains (losses) on investments
Net realized investment gains (losses)	33	(210)	181	(90)
Exchange \| Fixed maturities
Available-for-sale securities:
Gross realized gains	26	7	51	28
Gross realized losses	(5)	(3)	(17)	(12)
Net realized gains	21	4	34	16
Other-than-temporary impairments on investments
Total	0	(2)	0	(4)
Exchange \| Common stock
Trading securities:
Gross realized gains	71	44	127	89
Gross realized losses	(16)	(18)	(24)	(30)
Valuation adjustments	(53)	(242)	29	(171)
Net realized gains (losses)	2	(216)	132	(112)
Exchange \| Equity securities
Available-for-sale securities:
Gross realized gains	10	3	16	7
Gross realized losses	0	(1)	(1)	(1)
Net realized gains	10	2	15	6
Other-than-temporary impairments on investments
Total	$ 0	$ (1)	$ 0	$ (1)

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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