Deferred Policy Acquisition Costs (Schedule of deferred policy acquisition costs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Deferred Policy Acquisition Costs Disclosures [Abstract]
Balance, beginning of period	$ 8,980	$ 9,681	$ 8,859	$ 8,942
Deferral of policy acquisition costs	11,828	10,746	18,988	16,494
Amortization of deferred policy acquisition costs	(8,618)	(6,301)	(15,657)	(11,310)
Balance, end of period	$ 12,190	$ 14,126	$ 12,190	$ 14,126