Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 3,841	$ 3,671	$ 11,240	$ 11,148
Finance lease expense:
Amortization of assets	209	244	627	733
Interest on lease liabilities	4	11	17	39
Short-term lease expense	99	89	315	223
Variable lease expense	726	681	2,175	2,101
Total lease expense	$ 4,879	$ 4,696	$ 14,374	$ 14,244