Fair Value (Narrative) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	$ 6,722,858,000		$ 6,794,671,000
expense related to other repossessed assets	0
Alternative Investment	38,705,000		26,384,000
Loans Held-for-sale, Fair Value Disclosure	7,852,000		9,387,000
Impaired Financing Receivable, Carrying Value	$ 61,696,000		72,886,000
Discount percentage applied to real estate appraised values	15.00%
Discount percentage applied to lot development appraised values	6.00%
Partial Charge-Offs On Impaired Loans	$ 624,000		624,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,513,000		1,616,000
Impaired Loan Fair Value	827,000		1,103,000
Partial Charge-Offs On Impaired Loans carried at Fair Value	240,000		240,000
Book Value Of Impaired Loans Carried At Fair Value	970,000		1,291,000
Impaired Financing Receivable, carried at fair value, related expense	24,000	$ 900,000
MSR recorded at lower of cost or fair value	15,704,000	13,635,000	15,264,000	$ 12,210,000
Mortgage Servicing Rights Fair Value	14,000,000		13,500,000
Valuation allowance of MSR	1,126,000	2,337,000	1,568,000	$ 3,189,000
MSRs recorded at cost	1,700,000		1,800,000
Changes due to fair value adjustments	(442,000)	(852,000)
Other Real Estate, Foreclosed Assets, and Repossessed Assets	760,000		775,000
OREO valuation adjustments	30,000	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	17,400,000		8,400,000
Alternative Investment, income recognized	2,400,000	$ 1,400,000
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative Investment	21,300,000		18,000,000
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Financing Receivable, Related Allowance	143,000		188,000
Financing Receivable, not collateral dependent [Domain]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Financing Receivable, Related Allowance	1,370,000		1,428,000
Fair Value, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	$ 827,000		$ 1,103,000