Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net Income	$ 521	$ 730	$ 881
Adjustments to reconcile net income to net cash flows provided by operating activities:
Non-cash interest and operating expenses	36	26	39
Net amortization of premium (discount) on investments	(31)	(46)	(34)
Provision (benefit) for deferred income taxes	74	250	19
Net realized investment losses (gains)	32	(40)	29
Bargain purchase gain and settlement of pre-existing relationships	0	(58)	(259)
Change in premiums receivable, net of premiums and commissions payable	(6)	(69)	128
Change in ceded unearned premium reserve	58	90	22
Change in unearned premium reserve	39	(424)	(777)
Change in loss and loss adjustment expense reserve, net	(173)	142	(105)
Change in current income tax	(16)	(10)	27
Change in financial guaranty variable interest entities' assets and liabilities, net	(5)	(15)	(24)
Change in credit derivative assets and liabilities, net	(62)	(144)	(43)
Other	(5)	1	(35)
Net cash flows provided by (used in) operating activities	462	433	(132)
Fixed-maturity securities:
Purchases	(1,881)	(2,552)	(1,646)
Sales	1,180	1,701	1,365
Maturities	962	821	1,155
Short-term investments with maturities of over three months:
Purchases	(243)	(255)	(190)
Sales	23	102	172
Maturities	207	191	134
Net sales (purchases) of short-term investments with maturities of less than three months	(84)	36	(99)
Net proceeds from paydowns on financial guaranty variable interest entities’ assets	116	147	629
Acquisitions, net of cash acquired (see Note 2)	0	95	(435)
Proceeds from maturity of other invested asset	0	85	0
Other	17	(26)	(9)
Net cash flows provided by (used in) investing activities	297	345	1,076
Financing activities
Dividends paid	(71)	(70)	(69)
Repurchases of common stock	(500)	(501)	(306)
Repurchases of common stock to pay withholding taxes	(13)	(13)	(2)
Net paydowns of financial guaranty variable interest entities’ liabilities	(116)	(157)	(611)
Paydown of long-term debt	(101)	(30)	(2)
Proceeds from option exercises	6	5	12
Net cash flows provided by (used in) financing activities	(795)	(766)	(978)
Effect of foreign exchange rate changes	(4)	5	(5)
Increase (decrease) in cash and restricted cash	(40)	17	(39)
Cash and restricted cash at beginning of period (see Note 10)	144	127	166
Cash and restricted cash at end of period (see Note 10)	104	144	127
Supplemental cash flow information
Income taxes	(4)	10	74
Interest on long-term debt	$ 99	$ 77	$ 95