Accounting Policies (Details)	12 Months Ended
Dec. 31, 2021 USD ($) segment unit class Rate	Dec. 31, 2020 USD ($)
Securities
Held-to-maturity investment securities	$ 0	$ 0
Loans and leases
COVID-19 related loan and lease modifications	$ 0	129,000,000
Percentage of the principal balance that may be repurchased of a delinquent Ginnie Mae (GNMA) mortgage loan (as a percent)	100.00%
Allowance for credit losses
Number of segments within the loan and lease portfolio with similar risk characteristics \| class	9
Lease Commitments
Minimum lease liability for capitalization	$ 2,000
Residual value guarantees or restriction or covenants imposed by leases	no
Minimum initial lease term for recording right of use asset and lease liability	12 months
Other real estate
Carrying value of other real estate	$ 0	360,000
Repossessed assets
Repossessed assets value	$ 860,000	1,980,000
Goodwill and intangibles
Number of reportable units used in goodwill allocation \| unit	2
Goodwill impairment	$ 0
Partnership investment
Maximum percentage of partnership accounted for as equity investment \| Rate	50.00%
Investment in partnership	$ 95,050,000.00	76,350,000
Segment reporting
Number of business segments aggregated as reportable operating segments \| segment	1
Residential real estate portfolio
Loans and leases
Loans available for repurchase	$ 1,330,000	$ 2,310,000
Minimum
Loans and leases
Period of sustained performance required to change from non-performing to performing status	6 months
Equipment owned under operating lease
Lease term	3 years
Lease Commitments
Economic life test to determine lease classification	twenty years
Fair value test percentage of the fair value of the asset \| Rate	90.00%
Premises and equipment
Useful life of premises and equipment	3 years
Income taxes
Tax benefit realized on settlement, percentage	50.00%
Minimum \| Federal funds purchased
Short-term borrowings:
Term of short-term debt	1 day
Minimum \| Security repurchase agreements
Short-term borrowings:
Term of short-term debt	1 day
Minimum \| Other short-term borrowings
Short-term borrowings:
Term of short-term debt	1 day
Minimum \| Commercial paper
Short-term borrowings:
Term of short-term debt	7 days
Maximum
Allowance for credit losses
Current expected credit losses initial loss forecast term	2 years
Equipment owned under operating lease
Lease term	7 years
Premises and equipment
Useful life of premises and equipment	31 years 6 months
Goodwill and intangibles
Useful life of finite lived assets	25 years
Maximum \| Federal funds purchased
Short-term borrowings:
Term of short-term debt	365 days
Maximum \| Security repurchase agreements
Short-term borrowings:
Term of short-term debt	365 days
Maximum \| Other short-term borrowings
Short-term borrowings:
Term of short-term debt	365 days
Maximum \| Commercial paper
Short-term borrowings:
Term of short-term debt	270 days

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