Claims Reserve Claims Reserve (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Subscription business
Liability for Claims and Claims Adjustment Expense [Line Items]
Claims Reserve	$ 11,648	$ 9,500	$ 11,059	$ 8,538
Current Year Claims Incurred	45,198	36,518
Prior Year Claims Incurred	(61)	(195)
Current Year Claims Paid	36,142	28,868
Prior Years Claims Paid	8,250	6,400
Total Claims Paid	44,392	35,268
Claims expense non-cash	156	93
Total Claims Incurred	45,137	36,323
Other business
Liability for Claims and Claims Adjustment Expense [Line Items]
Claims Reserve	1,802	1,121	$ 1,697	$ 983
Current Year Claims Incurred	5,218	3,048
Prior Year Claims Incurred	(242)	(184)
Current Year Claims Paid	3,734	2,092
Prior Years Claims Paid	1,137	634
Total Claims Paid	4,871	2,726
Claims expense non-cash	0	0
Total Claims Incurred	$ 4,976	$ 2,864