Leases Lease payments and receipts (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Leases [Abstract]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 943
Operating Leases, Future Minimum Payments Receivable, Current	11,572
Operating Leases, Future Minimum Payments, Due in Two Years	405
Operating Leases, Future Minimum Payments Receivable, in Two Years	11,832
Operating Leases, Future Minimum Payments, Due in Three Years	404
Operating Leases, Future Minimum Payments Receivable, in Three Years	12,099
Operating Leases, Future Minimum Payments, Due in Four Years	401
Operating Leases, Future Minimum Payments Receivable, in Four Years	12,371
Operating Leases, Future Minimum Payments, Due in Five Years	401
Operating Leases, Future Minimum Payments Receivable, in Five Years	12,649
Operating Leases, Future Minimum Payments, Due Thereafter	817
Operating Leases, Future Minimum Payments Receivable, Thereafter	$ 149,896