Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Data [Abstract]

Schedule of quarterly financial information

Quarterly Financial Data

2011
(In millions, except per share data)	First			Second			Third		Fourth			Full Year
Revenues	$	2,315		$	2,198		$	2,175	$	2,259		$	8,947
Income from continuing operations	233			132			75		191			631
Income (loss) from discontinued operations, net of income tax (expense) benefit	(1		)	—			—		—			(1		)
Net (income) loss attributable to noncontrolling interests	(9		)	(6		)	—		(1		)	(16		)
Net income attributable to CNA	$	223		$	126		$	75	$	190		$	614
Basic and Diluted Earnings (Loss) Per Share
Income from continuing operations attributable to CNA common stockholders	$	0.83		$	0.47		$	0.28	$	0.70		$	2.28
Income (loss) from discontinued operations attributable to CNA common stockholders	—			—			—		—			—
Basic and diluted earnings per share attributable to CNA common stockholders	$	0.83		$	0.47		$	0.28	$	0.70		$	2.28

2010
(In millions, except per share data)	First			Second			Third			Fourth			Full Year
Revenues	$	2,315		$	2,233		$	2,363		$	2,298		$	9,209
Income (loss) from continuing operations	255			301			(103		)	326			779
Income (loss) from discontinued operations, net of income tax (expense) benefit	—			1			(22		)	—			(21		)
Net (income) loss attributable to noncontrolling interests	(10		)	(19		)	(15		)	(24		)	(68		)
Net income (loss) attributable to CNA	$	245		$	283		$	(140	)	$	302		$	690
Basic and Diluted Earnings (Loss) Per Share
Income (loss) from continuing operations attributable to CNA common stockholders	$	0.82		$	0.96		$	(0.51	)	$	1.09		$	2.36
Income (loss) from discontinued operations attributable to CNA common stockholders	—			—			(0.08		)	—			(0.08		)
Basic and diluted earnings (loss) per share attributable to CNA common stockholders	$	0.82		$	0.96		$	(0.59	)	$	1.09		$	2.28