Leases - Quantitative Lease Data (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finance Lease Amounts:
Right-of-Use Assets	$ 4,991	$ 5,171	$ 4,991	$ 5,171
Lease Liabilities	5,217	5,254	5,217	5,254
Operating Lease Amounts:
Right-of-Use Assets	5,326	5,644	5,326	5,644
Lease Liabilities	$ 5,410	$ 5,713	$ 5,410	$ 5,713
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization		us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities
Cash Paid For Amounts Included In The Measurement Of Lease Liabilities:
Operating Outgoing Cash Flows From Finance Leases			$ 196	$ 99
Operating Outgoing Cash Flows From Operating Leases			778	779
Financing Outgoing Cash Flows From Finance Leases			37	28
Right-of-Use Assets Obtained In Exchange For New Finance Lease Liabilities			0	5,271
Right-of-Use Assets Obtained In Exchange For New Operating Lease Liabilities			$ 294	$ 6,266
Weighted-average Remaining Lease Term - Finance Leases (Yrs.)	29 years 2 months 1 day	30 years 9 months 18 days	29 years 2 months 1 day	30 years 9 months 18 days
Weighted-average Remaining Lease Term - Operating Leases (Yrs.)	13 years 18 days	13 years 8 months 15 days	13 years 18 days	13 years 8 months 15 days
Weighted-average Discount Rate—Finance Leases	3.75%	3.75%	3.75%	3.75%
Weighted-average Discount Rate—Operating Leases	3.28%	3.35%	3.28%	3.35%
Finance Lease Cost:
Reduction in the Carrying Amount of Right-of-use assets	$ 44	$ 28	$ 177	$ 100
Interest on Lease Liabilities	48	28	196	99	$ 0
Operating Lease Cost	214	218	838	795
Short-term Lease Cost	8	12	40	85
Variable Lease Cost	39	65	204	205
Total Lease Cost	$ 353	$ 351	$ 1,455	$ 1,284