Reinsurance (Schedule of reconciliation of direct to net premiums on both a written and an earned basis) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Premiums Written
Direct premium	$ 83,671	$ 77,753	$ 120,051	$ 111,569
Assumed premium	3,396	5,926	4,591	7,430
Ceded premium	(8,953)	(27,331)	(11,431)	(30,877)
Net premiums	78,114	56,348	113,211	88,122
Premiums Earned
Direct premium	48,564	38,789	82,680	70,970
Assumed premium	3,368	5,933	4,539	7,413
Ceded premium	(6,279)	(7,586)	(8,757)	(11,132)
Net premiums	$ 45,653	$ 37,136	$ 78,462	$ 67,251
Percentage of assumed premium to net earned premium	7.40%	16.00%	5.80%	11.00%