Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Operating Activities:
Net Income	$ 1,088		$ 808		$ 110
Adjustments to reconcile net income to net cash flows provided by operating activities:
Non-cash interest and operating expenses	23		19		18
Net amortization of premium (discount) on investments	(16)		(8)		8
Provision (benefit) for deferred income taxes	347		177		(35)
Net realized investment losses (gains)	60		(52)		(1)
Net unrealized losses (gains) on credit derivatives	(800)	[1]	(107)	[1]	477	[1]
Fair value loss (gains) on committed capital securities	11		(10)		18
Change in deferred acquisition costs	3		(8)		18
Change in premiums receivable, net of commissions payable	108		86		48
Change in ceded unearned premium reserve	69		109		141
Change in unearned premium reserve	(332)		(612)		(749)
Change in loss and loss adjustment expense reserve, net	182		136		(258)
Change in current income tax	(45)		30		129
Change in financial guaranty variable interest entities' assets and liabilities, net	(170)		(295)		(7)
(Purchases) sales of trading securities, net	78		(16)		(59)
Other	(29)		(13)		(23)
Net cash flows provided by (used in) operating activities	577		244		(165)
Fixed-maturity securities:
Purchases	(2,801)		(1,886)		(1,649)
Sales	1,251		1,029		912
Maturities	877		883		1,105
Sales (purchases) of short-term investments, net	158		(87)		29
Net proceeds from paydowns on financial guaranty variable interest entities’ assets	408		663		545
Acquisition of MAC, net of cash acquired	0		0		(91)
Other	11		79		92
Net cash flows provided by (used in) investing activities	(96)		681		943
Financing activities
Proceeds from issuances of common stock	0		0		173
Dividends paid	(76)		(75)		(69)
Repurchases of common stock	(590)		(264)		(24)
Share activity under option and incentive plans	1		(1)		(3)
Net paydowns of financial guaranty variable entities’ liabilities	(396)		(511)		(724)
Net proceeds from issuance of long-term debt	495		0		0
Repayment of long-term debt	(19)		(27)		(209)
Net cash flows provided by (used in) financing activities	(585)		(878)		(856)
Effect of foreign exchange rate changes	(5)		(1)		1
Increase (decrease) in cash	(109)		46		(77)
Cash at beginning of period	184		138		215
Cash at end of period	75		184		138
Supplemental cash flow information
Income taxes	122		110		(24)
Interest	$ 86		$ 76		$ 85

[1] Except for net estimated credit impairments (i.e., net expected loss to be paid as discussed in Note 6), the unrealized gains and losses on credit derivatives are expected to reduce to zero as the exposure approaches its maturity date. With considerable volatility continuing in the market, unrealized gains (losses) on credit derivatives may fluctuate significantly in future periods.