Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease expense	$ 3,669	$ 3,773	$ 7,399	$ 7,477
Finance lease expense:
Amortization of assets	209	245	418	489
Interest on lease liabilities	6	13	13	28
Short-term lease expense	122	98	216	134
Variable lease expense	738	802	1,449	1,420
Total lease expense	$ 4,744	$ 4,931	$ 9,495	$ 9,548