Reinsurance - Effects of Reinsurance and Assumption Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Written premiums:
Direct	$ 18,855	$ 20,900
Assumed	4,882	5,574
Ceded	(3,892)	(4,150)
Net written premiums	19,845	22,324
Earned premiums:
Direct	21,224	22,060
Assumed	6,500	6,204
Ceded	(3,924)	(4,124)
Net earned premiums	23,800	24,140
Losses and LAE:
Direct	12,958	16,033
Assumed	3,554	3,875
Ceded	(3,184)	(4,175)
Total net incurred losses and LAE	$ 13,328	$ 15,733