Other Liabilities - Schedule of Unpaid Claims Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Unpaid claims liability at beginning of year	$ 3,896	$ 3,908	$ 3,121
Claims and claim adjustment expense for claims incurred in the current year	11,700	7,250	6,421
Claims and claim adjustment expense for claims incurred in the prior years	203	(87)	0
Payments for current year claims	(8,895)	(5,423)	(4,283)
Payments for prior year claims	(1,331)	(1,926)	(1,351)
Unpaid claims liability at the end of the year	$ 5,167	$ 3,896	$ 3,908