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, 2012	Dec. 31, 2011	Dec. 31, 2010
Insurance Loss Reserves [Abstract]
Gross reserves at January 1	$ 985,279	$ 1,034,205	$ 1,053,334
Less reinsurance recoverable	(7,921)	(6,805)	(7,748)
Net reserves at January 1	977,358	1,027,400	1,045,586
Incurred losses and loss adjustment expense related to:
Current year	1,919,116	1,810,711	1,838,824
Prior years	42,332	18,494	(13,058)
Total incurred losses and loss adjustment expenses	1,961,448	1,829,205	1,825,766
Loss and loss adjustment expense payments related to:
Current year	1,314,748	1,265,188	1,240,696
Prior years	600,090	614,059	603,256
Total payments	1,914,838	1,879,247	1,843,952
Net reserves at year-end	1,023,968	977,358	1,027,400
Reinsurance recoverable	12,155	7,921	6,805
Gross reserves at year-end	$ 1,036,123	$ 985,279	$ 1,034,205