Reinsurance (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Premiums Written:
Direct	$ 70,849	$ 38,174
Assumed	(1,600)	(1,278)
Gross written	69,249	36,896
Ceded	(21,996)	(14,267)
Net premiums written	47,253	22,629
Premiums Earned:
Direct	53,127	33,298
Assumed	29,420	21,400
Gross earned	82,547	54,698
Ceded	(21,996)	(14,267)
Net premiums earned	$ 60,551	$ 40,431