Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 258	$ 236
Operating lease payments	258	236
Operating lease right-of-use assets	653	1,388	$ 858
Operating lease liabilities	$ 653	$ 1,388
Weighted average remaining lease term	1 year	1 year 7 months 6 days
Weighted average discount rate	3.10%	3.10%
2021	$ 511
2022	138
2023	$ 4
Lessor, Operating Lease, Existence of Option to Extend [true false]	true
Property, plant and equipment, gross	$ 587,139	$ 567,808	$ 583,332
Lease income	$ 1,230	737
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	3 years
Commercial real estate leased to third parties
Lessee, Lease, Description [Line Items]
Property, plant and equipment, gross	$ 51,402	36,368
Depreciation	$ 15,001	$ 10,433
Commercial real estate leased to third parties | Maximum
Lessee, Lease, Description [Line Items]
Lessor, renewal term	60 years