Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Net premiums earned	$ 2,566,057	$ 2,566,685	$ 2,625,133
Net investment income	140,947	143,814	144,949
Net realized investment gains	58,397	57,089	346,444
Other	11,884	8,297	4,967
Total revenues	2,777,285	2,775,885	3,121,493
Expenses:
Losses and loss adjustment expenses	1,829,205	1,825,766	1,782,233
Policy acquisition costs	481,721	505,565	543,307
Other operating expenses	215,711	255,358	217,683
Interest	5,549	6,806	6,729
Total expenses	2,532,186	2,593,495	2,549,952
Income before income taxes	245,099	182,390	571,541
Income tax expense	53,935	30,192	168,469
Net income	$ 191,164	$ 152,198	$ 403,072
Net income per share:
Basic	$ 3.49	$ 2.78	$ 7.36
Diluted	$ 3.49	$ 2.78	$ 7.32