Consolidated Statement of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Total Shareholders' Equity Attributable to Assured Guaranty Ltd.	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Deferred Equity Compensation
Balance at Dec. 31, 2011	$ 4,651,565	$ 4,651,565	$ 1,822	$ 2,569,922	$ 1,707,922	$ 367,499	$ 4,400
Balance (in shares) at Dec. 31, 2011			182,235,798
Increase (Decrease) in Shareholders' Equity
Net loss	(106,476)	(106,476)	0	0	(106,476)	0	0
Dividends ($0.18 per share)		(32,878)	0	0	(32,878)	0	0
Dividends on restricted stock units		0	0	171	(171)	0	0
Common stock issuance, net, shares			13,428,770
Common stock issuance, net, value		172,500	134	172,366	0	0	0
Stock Repurchased During Period, Value		(24,313)	(21)	(24,292)	0	0	0
Stock Repurchased During Period, Shares			(2,066,759)
Share-based compensation and other		1,825	4	1,821	0	0	0
Share-based compensation and other (in shares)			358,672
Other comprehensive income	61,843	61,843	0	0	0	61,843	0
Balance at Jun. 30, 2012	4,724,066	4,724,066	1,939	2,719,988	1,568,397	429,342	4,400
Balance (in shares) at Jun. 30, 2012			193,956,481
Balance at Mar. 31, 2012
Increase (Decrease) in Shareholders' Equity
Net loss	376,548
Other comprehensive income	30,955					31,000
Balance at Jun. 30, 2012	$ 4,724,066					$ 429,342