Leases - Components of Lease Expense and Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 652	$ 1,958
Finance lease expense:
Amortization of right-of-use assets	357	577
Interest on lease liabilities	3	6
Total finance lease expense	360	583
Short-term lease expense	22	97
Total lease expense	1,034	2,638
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	584	1,749
Operating cash flows from finance leases	3	6
Financing cash flows from finance leases	$ 6	$ 51