Consolidated Statments of Comprehensive Income and Changes in Shareholders' Equity (Unaudited) (USD $) In Millions	Total	Shareholder Comprehensive Income Loss And Shareholders Equity [Member]	Common Stock	Additional Paid In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Stock	Noncontrolling Interest
Total Comprehensive Income and Total Equity, beginning of period at Jun. 30, 2010			$ 88	$ 2,526	$ (539)	$ 9,129	$ (5,228)	$ 15
Additional Paid In Capital, Effects of stock issuance for employee benefit plans				4
Net unrealized appreciation (depreciation), fixed maturities					198
Net unrealized appreciation (depreciation), equity securities					0
Net unrealized appreciation (depreciation) on securities	198				198
Net unrealized appreciation (depreciation), derivatives	(11)				(11)
Net translation of foreign currencies	66				66
Postretirement benefit liability adjustment	1				1
Other comprehensive income (loss)					254
Shareholders' net income	307					307
Retained Earnings, Effects of stock issuance for employee benefit plans						(15)
Repurchase of common stock							(78)
Other, primarily issuance of treasury stock for employee benefit plans							21
Net income attributable to noncontrolling interest	1							1
Accumulated other comprehensive income attributable to noncontrolling interest								1
Total Comprehensive Income and Total Equity, end of period at Sep. 30, 2010		6,469	88	2,530	(285)	9,421	(5,285)	17
Total Comprehensive Income and Total Equity, beginning of period at Dec. 31, 2009			88	2,514	(618)	8,625	(5,192)	12
Additional Paid In Capital, Effects of stock issuance for employee benefit plans				16
Effects of acquisition of noncontrolling interest				0
Net unrealized appreciation (depreciation), fixed maturities					389
Net unrealized appreciation (depreciation), equity securities					(1)
Net unrealized appreciation (depreciation) on securities	388				388
Net unrealized appreciation (depreciation), derivatives	9				9
Net translation of foreign currencies	27				27
Postretirement benefit liability adjustment	(91)				(91)
Other comprehensive income (loss)					333
Shareholders' net income	884					884
Retained Earnings, Effects of stock issuance for employee benefit plans						(77)
Common dividends declared (per share: $0.04; $0.04)						(11)
Repurchase of common stock							(201)
Other, primarily issuance of treasury stock for employee benefit plans							108
Net income attributable to noncontrolling interest	3							3
Accumulated other comprehensive income attributable to noncontrolling interest								2
Acquisition of noncontrolling interest								0
Total Comprehensive Income and Total Equity, end of period at Sep. 30, 2010		6,469	88	2,530	(285)	9,421	(5,285)	17
Total Comprehensive Income and Total Equity, beginning of period at Dec. 31, 2010	6,663		88	2,534	(614)	9,879	(5,242)	18
Additional Paid In Capital, Effects of stock issuance for employee benefit plans				23
Effects of acquisition of noncontrolling interest				4
Net unrealized appreciation (depreciation), fixed maturities					175
Net unrealized appreciation (depreciation), equity securities					(3)
Net unrealized appreciation (depreciation) on securities	172				172
Net unrealized appreciation (depreciation), derivatives	3				3
Net translation of foreign currencies	(15)				(15)
Postretirement benefit liability adjustment	13				13
Other comprehensive income (loss)					173
Shareholders' net income	1,037					1,037
Retained Earnings, Effects of stock issuance for employee benefit plans						(50)
Common dividends declared (per share: $0.04; $0.04)						(11)
Repurchase of common stock							(225)
Other, primarily issuance of treasury stock for employee benefit plans							165
Net income attributable to noncontrolling interest	1							1
Accumulated other comprehensive income attributable to noncontrolling interest								0
Acquisition of noncontrolling interest								(19)
Total Comprehensive Income and Total Equity, end of period at Sep. 30, 2011	7,761	7,761	88	2,561	(441)	10,855	(5,302)	0
Total Comprehensive Income and Total Equity, beginning of period at Jun. 30, 2011			88	2,556	(436)	10,658	(5,318)	0
Additional Paid In Capital, Effects of stock issuance for employee benefit plans				5
Net unrealized appreciation (depreciation), fixed maturities					94
Net unrealized appreciation (depreciation), equity securities					(3)
Net unrealized appreciation (depreciation) on securities	91				91
Net unrealized appreciation (depreciation), derivatives	13				13
Net translation of foreign currencies	(113)				(113)
Postretirement benefit liability adjustment	4				4
Other comprehensive income (loss)					(5)
Shareholders' net income	200					200
Retained Earnings, Effects of stock issuance for employee benefit plans						(3)
Repurchase of common stock							0
Other, primarily issuance of treasury stock for employee benefit plans							16
Net income attributable to noncontrolling interest	0							0
Total Comprehensive Income and Total Equity, end of period at Sep. 30, 2011	$ 7,761	$ 7,761	$ 88	$ 2,561	$ (441)	$ 10,855	$ (5,302)	$ 0