Claim and Claim Adjustment Expense Reserves (Tables)

3 Months Ended

Mar. 31, 2014

Claim and Claim Adjustment Expense Reserves [Abstract]

Net prior year development

Net Prior Year Development

Three months ended March 31, 2014
(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate & Other Non-Core		Total
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(2	)	$	17		$	10		$	—	$	25
Pretax (favorable) unfavorable premium development	(8		)	(19		)	(4		)	—		(31		)
Total pretax (favorable) unfavorable net prior year development	$	(10	)	$	(2	)	$	6		$	—	$	(6	)

Three months ended March 31, 2013
(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate & Other Non-Core		Total
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(15	)	$	(11	)	$	(1	)	$	1	$	(26	)
Pretax (favorable) unfavorable premium development	(8		)	(10		)	4			1		(13		)
Total pretax (favorable) unfavorable net prior year development	$	(23	)	$	(21	)	$	3		$	2	$	(39	)

Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment

Three months ended March 31
(In millions)	2014			2013
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Medical Professional Liability	$	1		$	(3	)
Other Professional Liability and Management Liability	(6		)	(1		)
Surety	1			1
Warranty	—			—
Other	2			(12		)
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(2	)	$	(15	)

Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment

Three months ended March 31
(In millions)	2014			2013
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Commercial Auto	$	20		$	(5	)
General Liability	(5		)	(21		)
Workers' Compensation	10			25
Property and Other	(8		)	(10		)
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	17		$	(11	)

Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment

Three months ended March 31
(In millions)	2014			2013
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Marine and Aviation	$	5		$	(1	)
Non-Marine Property	(2		)	—
Property Treaty	(2		)	—
Specialty	(1		)	—
Commutations	10			—
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	10		$	(1	)