Claims Reserve (Details) Claims Loss Roll-forward - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016
Subscription business
Supplementary Insurance Information, by Segment [Line Items]
Claims Reserve	$ 12,212	$ 9,609		$ 11,059	$ 8,538
Current Year Claims Incurred	91,464	74,244
Prior Year Claims Incurred	119	(257)	$ (300)
Total Claims Incurred	91,583	73,987
Current Year Claims Paid	80,841	65,549
Prior Years Claims Paid	9,256	7,138
Total Claims Paid	90,097	72,687
Claims expense non-cash	333	229
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	12,212
Other business
Supplementary Insurance Information, by Segment [Line Items]
Claims Reserve	1,784	1,211		$ 1,697	$ 983
Current Year Claims Incurred	10,589	6,337
Prior Year Claims Incurred	(279)	(128)
Total Claims Incurred	10,310	6,209
Current Year Claims Paid	8,916	5,217
Prior Years Claims Paid	1,307	764
Total Claims Paid	10,223	5,981
Claims expense non-cash	0	$ 0
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	1,784
Short-duration Insurance Contracts, Accident Year 2016 [Member] | Subscription business
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	386
Short-duration Insurance Contracts, Accident Year 2017 [Member] | Subscription business
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	1,537
Short-duration Insurance Contracts, Accident Year 2017 [Member] | Other business
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	110
Shortduration insurance contracts for accident year 2018 [Member] | Subscription business
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	10,289
Shortduration insurance contracts for accident year 2018 [Member] | Other business
Claims Reserve by Loss Year
Incurred but Not Reported (IBNR) Claims Liability	$ 1,674