Subsidiary Information - Condensed Consolidating Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Assets
Total investment portfolio and cash	$ 10,969		$ 11,223
Investment in subsidiaries	0		0
Premiums receivable, net of commissions payable	876	[1]	1,005	[1]	1,003	[1]	1,168
Ceded unearned premium reserve	452		561
Deferred acquisition costs	124		116		132		146
Reinsurance recoverable on unpaid losses	36		58
Credit derivative assets	94		141
Deferred tax asset, net	688		721
Intercompany receivable	0		0
Financial guaranty variable interest entities’ assets, at fair value	2,565		2,688
Other	483		729
Total assets	16,287		17,242
Liabilities and shareholders’ equity
Unearned premium reserve	4,595		5,207
Loss and loss adjustment expense reserve	592		601
Long-term debt	816		836
Intercompany payable	0		0
Credit derivative liabilities	1,787		1,934
Deferred tax liabilities, net	0
Financial guaranty variable interest entities’ liabilities, at fair value	2,871		3,141
Other	511		529
Total liabilities	11,172		12,248
Total shareholders' equity attributable to Assured Guaranty Ltd.	5,115		4,994		4,652		3,670
Noncontrolling interest	0
Total shareholders' equity	5,115
Total liabilities and shareholders’ equity	16,287		17,242
Assured Guaranty Ltd. (Parent)
Assets
Total investment portfolio and cash	33		245
Investment in subsidiaries	5,066		4,734
Premiums receivable, net of commissions payable	0		0
Ceded unearned premium reserve	0		0
Deferred acquisition costs	0		0
Reinsurance recoverable on unpaid losses	0		0
Credit derivative assets	0		0
Deferred tax asset, net	0		0
Intercompany receivable	0		0
Financial guaranty variable interest entities’ assets, at fair value	0		0
Other	23		23
Total assets	5,122		5,002
Liabilities and shareholders’ equity
Unearned premium reserve	0		0
Loss and loss adjustment expense reserve	0		0
Long-term debt	0		0
Intercompany payable	0		0
Credit derivative liabilities	0		0
Deferred tax liabilities, net	0
Financial guaranty variable interest entities’ liabilities, at fair value	0		0
Other	7		8
Total liabilities	7		8
Total shareholders' equity attributable to Assured Guaranty Ltd.	5,115		4,994
Noncontrolling interest	0
Total shareholders' equity	5,115
Total liabilities and shareholders’ equity	5,122		5,002
AGUS (Issuer)
Assets
Total investment portfolio and cash	186		15
Investment in subsidiaries	4,191		3,958
Premiums receivable, net of commissions payable	0		0
Ceded unearned premium reserve	0		0
Deferred acquisition costs	0		0
Reinsurance recoverable on unpaid losses	0		0
Credit derivative assets	0		0
Deferred tax asset, net	97		48
Intercompany receivable	0		0
Financial guaranty variable interest entities’ assets, at fair value	0		0
Other	17		29
Total assets	4,491		4,050
Liabilities and shareholders’ equity
Unearned premium reserve	0		0
Loss and loss adjustment expense reserve	0		0
Long-term debt	348		347
Intercompany payable	90		173
Credit derivative liabilities	0		0
Deferred tax liabilities, net	0
Financial guaranty variable interest entities’ liabilities, at fair value	0		0
Other	7		6
Total liabilities	445		526
Total shareholders' equity attributable to Assured Guaranty Ltd.	4,046		3,524
Noncontrolling interest	0
Total shareholders' equity	4,046
Total liabilities and shareholders’ equity	4,491		4,050
AGMH (Issuer)
Assets
Total investment portfolio and cash	42		30
Investment in subsidiaries	3,574		3,225
Premiums receivable, net of commissions payable	0		0
Ceded unearned premium reserve	0		0
Deferred acquisition costs	0		0
Reinsurance recoverable on unpaid losses	0		0
Credit derivative assets	0		0
Deferred tax asset, net	0		(94)
Intercompany receivable	0		0
Financial guaranty variable interest entities’ assets, at fair value	0		0
Other	31		26
Total assets	3,647		3,187
Liabilities and shareholders’ equity
Unearned premium reserve	0		0
Loss and loss adjustment expense reserve	0		0
Long-term debt	430		423
Intercompany payable	0		0
Credit derivative liabilities	0		0
Deferred tax liabilities, net	95
Financial guaranty variable interest entities’ liabilities, at fair value	0		0
Other	16		15
Total liabilities	541		438
Total shareholders' equity attributable to Assured Guaranty Ltd.	3,106		2,749
Noncontrolling interest	0
Total shareholders' equity	3,106
Total liabilities and shareholders’ equity	3,647		3,187
Other Entities
Assets
Total investment portfolio and cash	11,008		11,233
Investment in subsidiaries	289		3,524
Premiums receivable, net of commissions payable	1,025		1,147
Ceded unearned premium reserve	1,598		1,550
Deferred acquisition costs	198		190
Reinsurance recoverable on unpaid losses	170		223
Credit derivative assets	482		553
Deferred tax asset, net	681		789
Intercompany receivable	90		173
Financial guaranty variable interest entities’ assets, at fair value	2,565		2,688
Other	638		816
Total assets	18,744		22,886
Liabilities and shareholders’ equity
Unearned premium reserve	5,720		6,168
Loss and loss adjustment expense reserve	733		778
Long-term debt	38		66
Intercompany payable	300		300
Credit derivative liabilities	2,175		2,346
Deferred tax liabilities, net	0
Financial guaranty variable interest entities’ liabilities, at fair value	2,871		3,141
Other	853		803
Total liabilities	12,690		13,602
Total shareholders' equity attributable to Assured Guaranty Ltd.	5,765		9,284
Noncontrolling interest	289
Total shareholders' equity	6,054
Total liabilities and shareholders’ equity	18,744		22,886
Consolidating Adjustments
Assets
Total investment portfolio and cash	(300)		(300)
Investment in subsidiaries	(13,120)		(15,441)
Premiums receivable, net of commissions payable	(149)		(142)
Ceded unearned premium reserve	(1,146)		(989)
Deferred acquisition costs	(74)		(74)
Reinsurance recoverable on unpaid losses	(134)		(165)
Credit derivative assets	(388)		(412)
Deferred tax asset, net	(90)		(22)
Intercompany receivable	(90)		(173)
Financial guaranty variable interest entities’ assets, at fair value	0		0
Other	(226)		(165)
Total assets	(15,717)		(17,883)
Liabilities and shareholders’ equity
Unearned premium reserve	(1,125)		(961)
Loss and loss adjustment expense reserve	(141)		(177)
Long-term debt	0		0
Intercompany payable	(390)		(473)
Credit derivative liabilities	(388)		(412)
Deferred tax liabilities, net	(95)
Financial guaranty variable interest entities’ liabilities, at fair value	0		0
Other	(372)		(303)
Total liabilities	(2,511)		(2,326)
Total shareholders' equity attributable to Assured Guaranty Ltd.	(12,917)		(15,557)
Noncontrolling interest	(289)
Total shareholders' equity	(13,206)
Total liabilities and shareholders’ equity	$ (15,717)		$ (17,883)

[1] Excludes $21 million, $29 million and $28 million as of December 31, 2013 , 2012 and 2011, respectively, related to consolidated FG VIEs.