Losses And Loss Adjustment Expenses (Activity In The Reserves For Losses And Loss Adjustment Expenses) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Losses And Loss Adjustment Expenses [Abstract]
Gross reserves at January 1	$ 1,034,205	$ 1,053,334	$ 1,133,508
Less reinsurance recoverable	(6,805)	(7,748)	(5,729)
Net reserves at January 1	1,027,400	1,045,586	1,127,779
Current year	1,810,711	1,838,824	1,840,268
Prior years	18,494	(13,058)	(58,035)
Total incurred losses and loss adjustment expenses	1,829,205	1,825,766	1,782,233
Current year	1,265,188	1,240,696	1,246,804
Prior years	614,059	603,256	617,622
Total payments	1,879,247	1,843,952	1,864,426
Net reserves at year-end	977,358	1,027,400	1,045,586
Reinsurance recoverable	7,921	6,805	7,748
Gross reserves at year-end	$ 985,279	$ 1,034,205	$ 1,053,334