Premises, Equipment, and Leases - Weighted Average Remaining Lease Terms and Discount Rate (Details)	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Remaining Lease Terms
Weighed average remaining lease terms - operating leases	12 years 5 months 26 days	12 years 4 months 9 days
Weighed average remaining lease terms - finance leases	11 years 5 months 12 days	9 years 7 months 9 days
Weighted Average Discount Rate
Weighted average discount rate - operating leases	2.39%	3.24%
Weighted average discount rate - finance leases	3.05%	4.77%