CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Securities, available-for-sale, at fair value:
Fixed maturities (amortized cost, 2013 - $4,506,873; 2012 - $4,185,937)	$ 4,537,762	$ 4,227,339
Equity securities	2,928	2,936
Total investment portfolio	4,540,690	4,230,275
Cash and cash equivalents	1,635,810	1,027,625
Accrued investment income	31,290	27,243
Reinsurance recoverable on loss reserves (note 4)	96,179	104,848
Reinsurance recoverable on paid losses	13,283	15,605
Premium receivable	72,641	67,828
Home office and equipment, net	26,863	27,190
Deferred insurance policy acquisition costs	12,208	11,245
Other assets	79,534	62,465
Total assets	6,508,498	5,574,324
Liabilities:
Loss reserves (note 12)	3,848,348	4,056,843
Premium deficiency reserve (note 13)	72,131	73,781
Unearned premiums	140,213	138,840
Senior notes (note 3)	99,929	99,910
Convertible senior notes (note 3)	845,000	345,000
Convertible junior debentures (note 3)	389,522	379,609
Other liabilities	335,673	283,401
Total liabilities	5,730,816	5,377,384
Contingencies (note 5)
Shareholders' equity (note 14):
Common stock (one dollar par value, shares authorized 680,000; shares issued 2013 - 340,047; 2012 - 205,047; shares outstanding 2013 - 337,758; 2012 - 202,032)	340,047	205,047
Paid-in capital	1,657,567	1,135,296
Treasury stock (shares at cost 2013 - 2,289; 2012 - 3,015)	(64,435)	(104,959)
Accumulated other comprehensive loss, net of tax (note 9)	(57,801)	(48,163)
Retained deficit	(1,097,696)	(990,281)
Total shareholders' equity	777,682	196,940
Total liabilities and shareholders' equity	$ 6,508,498	$ 5,574,324