Leases - Components of Lease Expense and Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating Leases	$ 68	$ 137
Short-term leases	633	1,259
Total lease expense	701	1,396
Short-Term lease costs	$ 2,326	4,923
Cash paid for amounts included in the measurement of lease liabilities		137
Right-of-use assets obtained in exchange for operating lease obligations		$ 137