Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating lease cost
Operating lease expense	$ 1,182	$ 1,175	$ 2,360	$ 2,349
Variable lease expense	972	804	1,868	1,604
Finance lease cost
Amortization of right-of-use assets	88	78	176	148
Interest on lease liabilities	247	240	493	477
Total lease expense	2,489	2,297	4,897	4,578
Other information
Operating cash flows outflows related to operating leases	2,587	1,416	4,431	3,972
Financing cash flows outflows related to financing leases	321	2,847	683	3,168
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 0	$ 7,212	$ 0	$ 7,212
Weighted-average remaining lease term (excluding renewal options) - operating leases	48 years 1 month 6 days	49 years 1 month 6 days	48 years 1 month 6 days	49 years 1 month 6 days
Weighted-average remaining lease term (excluding renewal options) - finance leases	64 years 6 months	65 years	64 years 6 months	65 years
Weighted-average discount rate - operating leases	5.70%	5.70%	5.70%	5.70%
Weighted-average discount rate - finance leases	5.40%	5.40%	5.40%	5.40%