Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net Income	$ 730	$ 881	$ 1,056
Adjustments to reconcile net income to net cash flows provided by operating activities:
Non-cash interest and operating expenses	26	39	27
Net amortization of premium (discount) on investments	(46)	(34)	(25)
Provision (benefit) for deferred income taxes	250	19	300
Net realized investment losses (gains)	(40)	29	17
Net unrealized losses (gains) on credit derivatives	(121)	(69)	(746)
Fair value losses (gains) on committed capital securities	2	0	(27)
Bargain purchase gain and settlement of pre-existing relationships	(58)	(259)	(214)
Change in deferred acquisition costs	2	9	9
Change in premiums receivable, net of premiums and commissions payable	(69)	128	(8)
Change in ceded unearned premium reserve	90	22	79
Change in unearned premium reserve	(424)	(777)	(744)
Change in loss and loss adjustment expense reserve, net	142	(105)	244
Change in current income tax	(10)	27	(45)
Change in financial guaranty variable interest entities' assets and liabilities, net	(15)	(24)	(6)
Other	(26)	(18)	12
Net cash flows provided by (used in) operating activities	433	(132)	(71)
Fixed-maturity securities:
Purchases	(2,552)	(1,646)	(2,577)
Sales	1,701	1,365	2,107
Maturities	821	1,155	898
Net sales (purchases) of short-term investments	74	17	897
Net proceeds from paydowns on financial guaranty variable interest entities’ assets	147	629	400
Acquisitions, net of cash acquired (see Note 2)	95	(435)	(800)
Other	59	(9)	69
Net cash flows provided by (used in) investing activities	345	1,076	994
Financing activities
Dividends paid	(70)	(69)	(72)
Repurchases of common stock	(501)	(306)	(555)
Repurchases of common stock to pay withholding taxes	(13)	(2)	(7)
Net paydowns of FG VIE liabilities	(157)	(611)	(214)
Paydown of long-term debt	(30)	(2)	(4)
Proceeds from option exercises	5	12	5
Net cash flows provided by (used in) financing activities	(766)	(978)	(847)
Effect of foreign exchange rate changes	5	(5)	(4)
Increase (decrease) in cash and restricted cash	17	(39)	72
Cash and restricted cash at beginning of period	127	166	94
Cash and restricted cash at beginning of period	144	127	166
Supplemental cash flow information
Income taxes	10	74	103
Interest	$ 77	$ 95	$ 95