Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating lease cost
Operating lease expense	$ 1,175	$ 1,163	$ 2,349	$ 2,279
Variable lease expense	804	795	1,604	1,535
Amortization of right-of-use assets	78	51	148	51
Interest on lease liabilities	240	196	477	196
Total lease expense	2,297	2,205	4,578	4,061
Other information
Operating cash flows outflows related to operating leases	1,416	1,402	3,972	4,173
Financing cash flows outflows related to financing leases	2,847	142	3,168	142
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 7,212	$ 0	$ 7,212	$ 14,294
Weighted-average remaining lease term (excluding renewal options) - operating leases	49 years 1 month 6 days	49 years 10 months 24 days	49 years 1 month 6 days	49 years 10 months 24 days
Weighted-average remaining lease term (excluding renewal options) -finance leases	65 years	70 years 3 months 18 days	65 years	70 years 3 months 18 days
Weighted-average discount rate - operating leases	5.70%	5.50%	5.70%	5.50%
Weighted-average discount rate - finance leases	5.40%	5.90%	5.40%	5.90%