Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013
Statement of Cash Flows [Abstract]
Net cash flows provided by (used in) operating activities	$ 347	[1]	$ 146	[1]
Fixed-maturity securities:
Purchases	(2,031)		(1,563)
Sales	951		812
Maturities	557		643
Net sales (purchases) of short-term investments	89		44
Proceeds from paydowns on financial guaranty variable interest entities’ assets	346		553
Other	9		81
Net cash flows provided by (used in) investing activities	(79)		570
Financing activities
Dividends paid	(58)		(57)
Repurchases of common stock	(438)		(259)
Share activity under option and incentive plans	(1)		0
Paydowns of financial guaranty variable interest entities’ liabilities	(348)		(409)
Net proceeds from issuance of long-term debt	495		0
Repayment of long-term debt	(18)		(22)
Net cash flows provided by (used in) financing activities	(368)		(747)
Effect of exchange rate changes	(2)		(1)
Increase (decrease) in cash	(102)		(32)
Cash at beginning of period	184		138
Cash at end of period	82		106
Cash paid (received) during the period for:
Income taxes	68		81
Interest	$ 45		$ 47

[1] (1)Assured Guaranty Ltd., AGUS and AGMH net cash flows provided by (used in) operating activities includes dividends from subsidiaries.