Consolidated Condensed Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities:
Net income	$ 1,027	$ 1,282
Adjustments to reconcile net income to net cash provided (used) by operating activities, net	1,110	975
Changes in operating assets and liabilities, net:
Receivables	522	224
Deferred acquisition costs	(27)	(21)
Insurance reserves	(53)	(5)
Other assets	(14)	149
Other liabilities	(41)	(349)
Trading securities	(422)	(231)
Net cash flow operating activities	2,102	2,024
Investing Activities:
Purchases of fixed maturities	(7,369)	(8,854)
Proceeds from sales of fixed maturities	4,761	5,912
Proceeds from maturities of fixed maturities	2,655	2,434
Purchases of equity securities	(30)	(51)
Proceeds from sales of equity securities	72	171
Purchases of property, plant and equipment	(825)	(502)
Deposits for construction of offshore drilling equipment	(169)	(478)
Acquisitions	(367)
Dispositions	160	28
Change in short term investments	(637)	1,295
Change in other investments	(173)	(314)
Other, net	20	6
Net cash flow investing activities	(1,902)	(353)
Financing Activities:
Dividends paid	(74)	(76)
Dividends paid to noncontrolling interests	(330)	(297)
Acquisition of CNA Surety noncontrolling interests		(475)
Purchases of treasury shares	(139)	(700)
Issuance of common stock	9	4
Proceeds from sale of subsidiary stock	557	172
Principal payments on debt	(2,098)	(1,630)
Issuance of debt	1,918	1,351
Other, net	(6)	(11)
Net cash flow financing activities	(163)	(1,662)
Effect of foreign exchange rate on cash	3	(1)
Net change in cash	40	8
Cash, beginning of period	129	120
Cash, end of period	$ 169	$ 128