Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Net premiums earned	$ 662,595	$ 635,812
Net investment income	31,175	31,486
Net realized investment gains	44,050	52,663
Other	2,333	2,714
Total revenues	740,153	722,675
Expenses:
Losses and loss adjustment expenses	467,060	449,916
Policy acquisition costs	123,722	117,430
Other operating expenses	58,063	52,925
Interest	314	410
Total expenses	649,159	620,681
Income before income taxes	90,994	101,994
Income tax expense	24,533	28,638
Net income	$ 66,461	$ 73,356
Net income per share:
Basic (in dollars per share)	$ 1.21	$ 1.34
Diluted (in dollars per share)	$ 1.21	$ 1.34
Weighted average shares outstanding:
Basic (in shares)	54,922	54,877
Diluted (in shares)	54,935	54,908
Dividends paid per share (in dollars per share)	$ 0.6125	$ 0.61