Condensed Consolidated Statements of Equity (USD $) In Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Notes Receivable [Member]	Parent Company [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2009		$ 1,000	$ 683	$ 2,177	$ 7,264	$ (325)	$ (109)	$ (30)		$ 506
Net income (loss)	557				528					29
Other Comprehensive Income (Loss)	732					715				17
Dividends paid to common stockholders					0
Dividends paid to Loews Corporation for 2008 Senior Preferred					(50)
Stock-based compensation				0			3
(Increase) Decrease in notes receivable from the issuance of common stock								0
Acquisition of CNA Surety noncontrolling interest				0		0				0
Other				23						(26)
Balance at Jun. 30, 2010	12,405	1,000	683	2,200	7,742	390	(106)	(30)	11,879	526
Balance at Dec. 31, 2010	11,524	0	683	2,200	7,876	326	(105)	(26)		570
Net income (loss)	364				349					15
Other Comprehensive Income (Loss)	393					385				8
Dividends paid to common stockholders					(54)
Dividends paid to Loews Corporation for 2008 Senior Preferred					0
Stock-based compensation				1			3
(Increase) Decrease in notes receivable from the issuance of common stock								3
Acquisition of CNA Surety noncontrolling interest				(60)		19				(434)
Other				2						(12)
Balance at Jun. 30, 2011	$ 11,749	$ 0	$ 683	$ 2,143	$ 8,171	$ 730	$ (102)	$ (23)	$ 11,602	$ 147