Commitments and Contingencies Lease Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Operating Leases, Rent Expense	$ 7,900	$ 600	$ 400
Operating Leases, Future Minimum Payments Due, Next Twelve Months	8,775
Operating Leases, Future Minimum Payments, Due in Two Years	5,907
Operating Leases, Future Minimum Payments, Due in Three Years	4,059
Operating Leases, Future Minimum Payments, Due in Four Years	3,214
Operating Leases, Future Minimum Payments, Due in Five Years	3,105
Operating Leases, Future Minimum Payments, Due Thereafter	6,446
Operating Leases, Future Minimum Payments Due	$ 31,506