Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finance lease cost:
Amortization of right-of-use assets	$ 1,424	$ 1,429	$ 506
Interest on lease liabilities	177	303	123
Total finance lease cost	1,601	1,732	629
Operating lease cost	1,586	1,607	1,716
Total lease cost	$ 3,187	$ 3,339	$ 2,345