Income Taxes (Components Of Deferred Tax Assets and Liabilities) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Deferred tax liabilities [Abstract]
Unearned premium reserve	$ 220		$ 241
Loss and loss adjustment expense reserves	0		0
Deferral of cancellation of indebtedness income	114	[1]	114	[1]
Deferred acquisition costs	87		102
Investments in VIEs	0		0
Net unrealized gains in accumulated other comprehensive income	0		32
Other	57		64
Total gross deferred tax liabilities	478		553
Deferred tax assets [Abstract]
Compensation and employee benefits	31		23
Loss and loss adjustment expense reserves	85		112
Net operating loss and tax credit carryforwards	917		441
Capital loss carryforward and other-than-temporary impairments	93		183
Net unrealized losses on insured derivatives	400		982
Net losses on financial instruments at fair value and foreign exchange	47		98
Net unrealized losses in accumulated other comprehensive income	30		0
Alternative minimum tax credit carryforward	22		19
Net deferred taxes on VIEs	55		40
Other	0		0
Total gross deferred tax assets	1,680		1,898
Valuation allowance	93		146
Net deferred tax asset	$ 1,109		$ 1,199

[1] Pursuant to Internal Revenue Code Section 108(i), cancellation of indebtedness income will be amortized ratably into taxable income over five years beginning in 2014.