Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 819	$ 1,966
Finance lease costs:
Amortization of right-of-use assets	152	611
Interest on lease liabilities	22	64
Total lease costs	$ 993	$ 2,641