Fair Value (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	$ 6,811,368,000		$ 6,811,368,000		$ 6,794,671,000
expense related to other repossessed assets			0	$ 0
Alternative Investment	43,579,000		43,579,000		26,384,000
Loans Held-for-sale, Fair Value Disclosure	5,679,000		5,679,000		9,387,000
Impaired Financing Receivable, Carrying Value	40,649,000		$ 40,649,000		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			$ 382,000		624,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,874,000		1,874,000		1,616,000
Impaired Loan Fair Value	2,732,000		2,732,000		1,103,000
Partial Charge-Offs On Impaired Loans carried at Fair Value			162,000		240,000
Book Value Of Impaired Loans Carried At Fair Value	3,892,000		3,892,000		1,291,000
Impaired Financing Receivable, carried at fair value, related expense	(1,000,000.0)	$ (400,000)	(1,000,000.0)	500,000
MSR recorded at lower of cost or fair value	16,470,000	14,316,000	16,470,000	14,316,000	15,264,000	$ 15,704,000	$ 13,635,000	$ 12,210,000
Mortgage Servicing Rights Fair Value	1,500,000		1,500,000		13,500,000
Valuation allowance of MSR	232,000	2,112,000	232,000	2,112,000	1,568,000	$ 1,126,000	$ 2,337,000	$ 3,189,000
MSRs recorded at cost	15,000,000		15,000,000		1,800,000
Changes due to fair value adjustments	(894,000)	(225,000)	(1,336,000)	(1,077,000)
Other Real Estate, Foreclosed Assets, and Repossessed Assets	1,354,000		1,354,000		775,000
OREO valuation adjustments	735,000		765,000	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	20,300,000		20,300,000		8,400,000
Alternative Investment, income recognized	90,000	$ 506,000	2,500,000	$ 1,900,000
Financing Receivable, Transfer to Held-for-Sale, Valuation Allowance, Expense			1,200,000
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative Investment	23,200,000		23,200,000		18,000,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	6,805,564,000		6,805,564,000		6,784,951,000
Impaired Loan Fair Value	2,732,000		2,732,000		1,103,000
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Financing Receivable, Related Allowance	1,160,000		1,160,000		188,000
Financing Receivable, not collateral dependent [Domain]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Financing Receivable, Related Allowance	714,000		714,000		1,428,000
Fair Value, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	2,732,000		2,732,000		1,103,000
Financing Receivable, Held for sale amortized cost	1,400,000		1,400,000
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	2,732,000		2,732,000		$ 1,103,000
Other Real Estate, Foreclosed Assets, and Repossessed Assets	$ 0		$ 0