Reserves for Unpaid Losses and Loss Adjustment Expenses (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Balance at January 1	$ 296,945	$ 251,677	$ 184,662
Less reinsurance recoverable	42,044	37,954	8,412
Net Balance at January 1	254,901	213,723	176,250
Acquisition of subsidiaries effective July 1	0	8,816	0
Incurred related to:
Current year	230,089	222,869	193,354
Prior years	(3,675)	16,366	9,190
Total incurred	226,414	239,235	202,544
Paid related to:
Current year	107,945	101,025	91,424
Prior years	109,538	105,848	73,647
Total paid	217,483	206,873	165,071
Net Balance at December 31	263,832	254,901	213,723
Plus reinsurance recoverable	49,584	42,044	37,954
Balance at December 31	$ 313,416	$ 296,945	$ 251,677