Leases and Rentals - Schedule of Future Minimum Lease Payments for Capital Leases (Details)
$ in Thousands
Dec. 31, 2017
USD ($)
Leases [Abstract]  
2018 $ 74
2019 48
Total minimum lease payments 122
Less: estimated executory costs 0
Net minimum lease payments 122
Less: amount representing interest (1)
Present value of net minimum lease payments $ 121