Leases - Finance Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finance Leases:
Gross cost	$ 5,007	$ 3,609
Accumulated depreciation	(2,153)	(1,322)
Operating lease right-of-use assets	2,854	$ 2,287
Total finance lease liabilities	144
Finance Leases
Finance Leases:
Gross cost	435
Accumulated depreciation	(296)
Operating lease right-of-use assets	139
Other current liabilities	$ 135
Financial position	us-gaap:OtherLiabilitiesCurrent
Other liabilities	$ 159
Financial position	us-gaap:OtherLiabilitiesNoncurrent
Total finance lease liabilities	$ 294