Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Comprehensive Income [Line Items]
Shareholders' net income	$ 466	$ 183	$ 1,217	$ 987
Net unrealized appreciation (depreciation), fixed maturities	83	94	169	175
Net unrealized appreciation (depreciation), equity securities	0	(3)	2	(3)
Net unrealized appreciation (depreciation) on securities	83	91	171	172
Net unrealized appreciation (depreciation), derivatives	(4)	13	(4)	3
Net translation of foreign currencies	31	(95)	23	(7)
Postretirement benefits liability adjustment	8	4	44	13
Shareholders' Other comprehensive income (loss)	118	13	234	181
Shareholders' comprehensive income	584	196	1,451	1,168
Net income attributable to noncontrolling interest	0	0	0	1
Total Comprehensive income	$ 584	$ 196	$ 1,451	$ 1,169