Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Investment portfolio:
Fixed maturity securities, available-for-sale, at fair value (amortized cost of $9,596,052 and $9,289,444)	$ 9,864,203	$ 9,415,315
Short-term investments, at fair value	1,070,401	1,031,578
Other invested assets	252,082	283,032
Total investment portfolio	11,186,686	10,729,925
Cash	159,170	107,179
Premiums receivable, net of ceding commissions payable	1,059,461	1,167,587
Ceded unearned premium reserve	773,321	821,819
Deferred acquisition costs	232,311	239,805
Reinsurance recoverable on unpaid losses	26,025	22,255
Salvage and subrogation recoverable	307,147	1,032,369
Credit derivative assets	603,867	592,898
Deferred tax asset, net	1,012,011	1,223,958
Current income tax receivable	187,969
Financial guaranty variable interest entities' assets, at fair value	3,492,204	3,657,481
Other assets	198,692	199,308
Total assets	19,238,864	19,794,584
Liabilities and shareholders' equity
Unearned premium reserve	6,315,362	6,972,894
Loss and loss adjustment expense reserve	518,145	562,955
Reinsurance balances payable, net	175,875	274,431
Long-term debt	1,046,382	1,052,936
Credit derivative liabilities	2,788,218	2,465,520
Current income tax payable		93,020
Financial guaranty variable interest entities' liabilities with recourse, at fair value	2,755,113	2,926,988
Financial guaranty variable interest entities' liabilities without recourse, at fair value	1,282,463	1,337,214
Other liabilities	407,321	309,862
Total liabilities	15,288,879	15,995,820
Commitments and contingencies (See Note 12)
Common stock ($0.01 par value, 500,000,000 shares authorized; 184,192,736 and 183,744,655 shares issued and outstanding in 2011 and 2010)	1,842	1,837
Additional paid-in capital	2,590,654	2,585,423
Retained earnings	1,149,898	1,098,859
Accumulated other comprehensive income, net of tax provision (benefit) of $66,293 and $17,746	205,591	110,645
Deferred equity compensation (181,818 shares)	2,000	2,000
Total shareholders' equity	3,949,985	3,798,764
Total liabilities and shareholders' equity	$ 19,238,864	$ 19,794,584