Consolidated Statements of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Net cash flows provided by (used in) operating activities	$ 600,998	$ (104,267)
Fixed maturity securities:
Purchases	(1,787,990)	(1,928,744)
Sales	848,416	835,716
Maturities	502,929	729,559
Net sales (purchases) of short-term investments	182,407	731,216
Net proceeds from paydowns on financial guaranty variable interest entities' assets	598,160	323,626
Other	13,988	15,718
Net cash flows provided by (used in) investing activities	357,910	707,091
Financing activities
Dividends paid	(24,830)	(24,889)
Repurchases of common stock	(23,311)	(10,457)
Share activity under option and incentive plans	(2,609)	(2,323)
Net paydowns of financial guaranty variable interest entities' liabilities	(830,063)	(497,296)
Repayment of long-term debt	(16,902)	(16,090)
Net cash flows provided by (used in) financing activities	(897,715)	(551,055)
Effect of foreign exchange rate changes	3,678	(1,496)
Increase (decrease) in cash	64,871	50,273
Cash at beginning of period	108,389	44,133
Cash at end of period	173,260	94,406
Cash paid (received) during the period for:
Income taxes	89,202	138,073
Interest	$ 58,100	$ 58,587