Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Comprehensive Income [Line Items]
Net unrealized appreciation (depreciation) on securities	$ 87	$ 118	$ 81	$ 190
Net unrealized appreciation (depreciation), derivatives	(5)	16	(10)	20
Net translation of foreign currencies	46	(43)	98	(39)
Postretirement benefits liability adjustment	5	(100)	9	(92)
Shareholders' net income	408	294	837	577
Net income attributable to noncontrolling interest	0	1	1	2
Comprehensive Income
Comprehensive Income [Line Items]
Net unrealized appreciation (depreciation), fixed maturities	89	119	81	191
Net unrealized appreciation (depreciation), equity securities	(2)	(1)	0	(1)
Net unrealized appreciation (depreciation) on securities	87	118	81	190
Net unrealized appreciation (depreciation), derivatives	(5)	16	(10)	20
Net translation of foreign currencies	46	(43)	98	(39)
Postretirement benefits liability adjustment	5	(100)	9	(92)
Other comprehensive income (loss)	133	(9)	178	79
Shareholders' net income	408	294	837	577
Net income attributable to noncontrolling interest	0	1	1	2
Accumulated other comprehensive income attributable to noncontrolling interest			$ 0	$ 1