Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Finance lease expense:
Amortization of right-of-use assets	$ 8	$ 33
Interest on lease liabilities	0	1
Operating lease expense	1,590	1,644
Short-term lease expense	382	224
Variable lease expense	42	36
Total lease expense	$ 2,022	$ 1,938