Unpaid Loss and Loss Adjustment Expenses Vehicle Service Agreements (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Vehicle service agreements	$ 2,794	$ 2,975	$ 2,915
Other Insurance Product Line [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Current year	2,558	2,654
Prior years	0	0
Current year	2,616	2,502
Prior years	$ (63)	$ (152)
Vehicle service agreements			$ 2,915	$ 2,975