Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Comprehensive Income [Line Items]
Shareholders' net income	$ 371	$ 413
Net unrealized appreciation (depreciation), fixed maturities	23	(8)
Net unrealized appreciation (depreciation), equity securities	1	2
Net unrealized appreciation (depreciation) on securities	24	(6)
Net unrealized appreciation (depreciation), derivatives	(5)	(5)
Net translation of foreign currencies	35	48
Postretirement benefits liability adjustment	11	4
Shareholders' Other comprehensive income (loss)	65	41
Shareholders' comprehensive income	436	454
Net income attributable to noncontrolling interest	0	1
Total Comprehensive income	$ 436	$ 455