SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) segment partnership shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($)	Jan. 01, 2021 USD ($)	Dec. 31, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Financing Receivable, Accrued Interest, after Allowance for Credit Loss	$ 10,000,000.0	$ 14,600,000
Threshold for loans individually analyzed for impairment	250,000
Investment in limited partnerships	$ 9,400,000	9,200,000
Number of additional partnerships required to fund | partnership	4
Commitment to fund limited partnerships	$ 2,200,000	2,600,000
Balance of real estate owned	196,000	316,000
Loan servicing fees	1,200,000	1,200,000	$ 1,100,000
Mortgage servicing rights	2,400,000	3,500,000
Unpaid principal balances	375,400,000	351,000,000.0
Escrow deposit	1,700,000
Bank owned life insurance	$ 97,652,000	$ 95,227,000
Treasury stock (in shares) | shares	476,816	473,660
Weighted average price (in USD per share) | $ / shares		$ 34.63
Number of reportable operating segments | segment	1
Shares purchased under director deferred compensation plan included in treasury stock (in shares) | shares	187,715	184,559
Repurchased common shares (in shares) | shares		289,101
Total ending allowance balance	$ 67,773,000	$ 61,408,000	$ 50,652,000		$ 48,453,000
Retained Earnings (Accumulated Deficit)	(583,134,000)	(529,005,000)
Impact of ASC 326 Adoption
Summary Of Significant Accounting Policies [Line Items]
Total ending allowance balance		9,050,000		$ 9,050,000
Impact of ASC 326 Adoption | ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Total ending allowance balance				9,100,000
Retained Earnings (Accumulated Deficit)				7,000,000
Deferred Income Tax Assets, Net				$ 2,100,000
Interest Rate Swap
Summary Of Significant Accounting Policies [Line Items]
Notional amount	796,000,000.0	819,100,000
Fair value of interest rate swap asset	14,300,000	21,800,000
Fair value of interest rate swap liability	14,300,000	21,800,000
Amount of risk participation transactions	4,600,000	5,000,000
Life Insurance | Officer
Summary Of Significant Accounting Policies [Line Items]
Bank owned life insurance	91,100,000	90,400,000
Deferred Compensation | Officer
Summary Of Significant Accounting Policies [Line Items]
Bank owned life insurance	$ 6,600,000	$ 4,800,000
Premises and Improvements | Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life	5 years
Premises and Improvements | Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life	40 years
Furniture Assets | Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life	3 years
Furniture Assets | Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life	7 years