Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Comprehensive Income [Line Items]
Net unrealized appreciation (depreciation) on securities	$ 91	$ 198	$ 172	$ 388
Net unrealized appreciation (depreciation), derivatives	13	(11)	3	9
Net translation of foreign currencies	(113)	66	(15)	27
Postretirement benefits liability adjustment	4	1	13	(91)
Shareholders' net income	200	307	1,037	884
Net income attributable to noncontrolling interest	0	1	1	3
Comprehensive Income
Comprehensive Income [Line Items]
Net unrealized appreciation (depreciation), fixed maturities	94	198	175	389
Net unrealized appreciation (depreciation), equity securities	(3)	0	(3)	(1)
Net unrealized appreciation (depreciation) on securities	91	198	172	388
Net unrealized appreciation (depreciation), derivatives	13	(11)	3	9
Net translation of foreign currencies	(113)	66	(15)	27
Postretirement benefits liability adjustment	4	1	13	(91)
Other comprehensive income (loss)	(5)	254	173	333
Shareholders' net income	200	307	1,037	884
Net income attributable to noncontrolling interest	0	1	1	3
Accumulated other comprehensive income attributable to noncontrolling interest			$ 0	$ 2