Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Changes in:
Net unrealized gains (losses) on investments with other-than-temporary impairments	$ 1	$ 17	$ 39	$ 42
Net unrealized gains (losses) on other investments	300	377	322	700
Net unrealized gains (losses) on investments	301	394	361	742
Net unrealized gains (losses) on discontinued operations and other	0	1	1	8
Foreign currency translation adjustment	5	17	30	7
Pension and postretirement benefits	1	2	2	3
Allocation to participating policyholders	(1)	(5)	(1)	(28)
Other Comprehensive Income (Loss), Net of Tax	306	409	393	732
Net income (loss)	132	302	364	557
Comprehensive income (loss)	438	711	757	1,289
Changes in:
Net unrealized (gains) losses on investments attributable to noncontrolling interests	(10)	(8)	(8)	(14)
Pension and postretirement benefits attributable to noncontrolling interests	0	0	0	(3)
Other comprehensive (income) loss attributable to noncontrolling interests	(10)	(8)	(8)	(17)
Net (income) loss attributable to noncontrolling interests	(6)	(19)	(15)	(29)
Comprehensive (income) loss attributable to noncontrolling interests	(16)	(27)	(23)	(46)
Total comprehensive income (loss) attributable to CNA	$ 422	$ 684	$ 734	$ 1,243