Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 272	$ 257	$ 272	$ 257
Operating lease payments	781	751	781	751
Operating lease right-of-use assets	7,617	1,062	7,617	1,062	$ 858
Operating lease liabilities	$ 7,617	$ 1,062	$ 7,617	$ 1,062
Weighted average remaining lease term	8 years 1 month 6 days	1 year	8 years 1 month 6 days	1 year
Weighted average discount rate	2.30%	3.00%	2.30%	3.00%
2021 (rest of year)	$ 279		$ 279
2022	1,011		1,011
2023	725		725
2024	421		421
2025	422		422
Thereafter	4,759		$ 4,759
Lessor, Operating Lease, Existence of Option to Extend [true false]			true
Property, plant and equipment, gross	614,091	$ 576,250	$ 614,091	$ 576,250	$ 583,332
Lease income	$ 945	802	$ 3,021	2,328
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	$ 10,794
Commercial real estate leased to third parties | Maximum
Lessee, Lease, Description [Line Items]
Lessor, renewal term	60 years		60 years