Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 255	$ 258	$ 255	$ 258
Operating lease payments	513	494	513	494
Operating lease right-of-use assets	6,892	1,265	6,892	1,265	$ 858
Operating lease liabilities	$ 6,892	$ 1,265	$ 6,892	$ 1,265
Weighted average remaining lease term	8 years 1 month 6 days	1 year 3 months 18 days	8 years 1 month 6 days	1 year 3 months 18 days
Weighted average discount rate	2.10%	3.00%	2.10%	3.00%
2021 (rest of year)	$ 447		$ 447
2022	575		575
2023	392		392
2024	387		387
2025	387		387
Thereafter	4,704		$ 4,704
Lessor, Operating Lease, Existence of Option to Extend [true false]			true
Property, plant and equipment, gross	602,204	$ 570,895	$ 602,204	$ 570,895	$ 583,332
Lease income	$ 845	788	$ 2,075	1,526
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	3 years		3 years
Commercial real estate leased to third parties
Lessee, Lease, Description [Line Items]
Property, plant and equipment, gross	$ 51,402	$ 36,378	$ 51,402	36,378
Depreciation			$ 15,314	$ 10,613
Commercial real estate leased to third parties | Maximum
Lessee, Lease, Description [Line Items]
Lessor, renewal term	60 years		60 years