Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Investments
Fixed maturity securities - available for sale, at fair value (amortized cost: 2013 - $5,819,392 and 2012 - $5,856,432)	$ 6,185,456	$ 6,281,781
Equity securities - available for sale, at fair value (cost: 2013 - $319,499 and 2012 - $275,827)	350,352	284,639
Short-term investments, at cost (approximates fair value)	267,434	363,053
Other investments, at fair value (cost: 2013 - $1,997 and 2012 - $18,391)	2,810	20,925
Total investments	6,806,052	6,950,398
Cash	75,677	71,390
Restricted cash and securities	101,572	101,480
Premium, claims and other receivables	577,946	549,725
Reinsurance recoverables	1,066,351	1,071,222
Ceded unearned premium	257,359	256,988
Ceded life and annuity benefits	58,227	58,641
Deferred policy acquisition costs	192,199	191,960
Goodwill	885,994	885,860
Other assets	176,839	130,143
Total assets	10,198,216	10,267,807
LIABILITIES
Loss and loss adjustment expense payable	3,774,162	3,767,850
Life and annuity policy benefits	58,227	58,641
Reinsurance, premium and claims payable	321,394	294,621
Unearned premium	1,085,833	1,069,956
Deferred ceding commissions	72,992	74,609
Notes payable	618,982	583,944
Accounts payable and accrued liabilities	681,377	875,574
Total liabilities	6,612,967	6,725,195
SHAREHOLDERS' EQUITY
Common stock, $1.00 par value; 250,000 shares authorized (shares issued: 2013 - 125,394 and 2012 - 125,114; outstanding: 2013 - 100,474 and 2012 - 100,928)	125,394	125,114
Additional paid-in capital	1,061,272	1,052,253
Retained earnings	2,845,444	2,756,166
Accumulated other comprehensive income	268,100	295,271
Treasury stock, at cost (shares: 2013 - 24,920 and 2012 - 24,186)	(714,961)	(686,192)
Total shareholders' equity	3,585,249	3,542,612
Total liabilities and shareholders' equity	$ 10,198,216	$ 10,267,807