Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease expense	$ 3,730	$ 3,704
Finance lease expense:
Amortization of assets	209	244
Interest on lease liabilities	7	15
Short-term lease expense	94	36
Variable lease expense	711	618
Total lease expense	$ 4,751	$ 4,617