JUNIOR SUBORDINATED DEBENTURES AND MANDATORILY REDEEMABLE TRUST PREFERRED SECURITIES (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) subsidiary	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Schedule of Trust Preferred Securities [Line Items]
Number of wholly-owned Grantor Trusts | subsidiary	9
Grantor trusts amount of tier one risk based capital	$ 1,440,694,000	$ 1,371,736,000
Loss on extinguishment of debt	2,284,000	0	$ 735,000
Repayment of junior subordinated debentures	8,248,000	$ 0	$ 0
Aggregate Liquidation Amount of Trust Preferred Securities [Member]
Schedule of Trust Preferred Securities [Line Items]
Repayment of junior subordinated debentures	8,000,000
Common Stock [Member]
Schedule of Trust Preferred Securities [Line Items]
Repayment of junior subordinated debentures	248,000
Junior Subordinated Debt [Member]
Schedule of Trust Preferred Securities [Line Items]
Long-term Debt, Gross	$ 100,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Debentures Subject to Mandatory Redemption [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 139,696,000
Fair value adjustment	(19,881,000)
Total TPS liability at fair value	$ 119,815,000
Current Interest Rate	2.24%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trusts [Member]
Schedule of Trust Preferred Securities [Line Items]
Grantor trusts amount of tier one risk based capital	$ 135,500,000
Grantor trusts percentage of tier one risk based capital	8.10%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust II [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 15,464,000
Current Interest Rate	3.47%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	3.35%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust III [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 15,465,000
Current Interest Rate	3.02%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	2.90%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust IV [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 15,465,000
Current Interest Rate	2.97%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	2.85%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust V [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 25,774,000
Current Interest Rate	1.73%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.57%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust VI [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 25,774,000
Current Interest Rate	1.79%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.62%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust VII [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 25,774,000
Current Interest Rate	1.51%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.38%
Debentures Subject to Mandatory Redemption [Member] | Greater Sacramento Bancorp Statutory Trust one [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 4,124,000
Current Interest Rate	3.47%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	3.35%
Debentures Subject to Mandatory Redemption [Member] | Greater Sacramento Bancorp Statutory Trust Two [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 4,124,000
Current Interest Rate	1.88%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.68%
Debentures Subject to Mandatory Redemption [Member] | Mission Oaks Statutory Trust One [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 7,732,000
Current Interest Rate	1.85%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.65%
Aggregate Liquidation Amount of Trust Preferred Securities [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 135,500,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust II [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	15,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust III [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	15,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust IV [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	15,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust V [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	25,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust VI [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	25,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust VII [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	25,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Greater Sacramento Bancorp Statutory Trust one [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	4,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Greater Sacramento Bancorp Statutory Trust Two [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	4,000,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Mission Oaks Statutory Trust One [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	7,500,000
Aggregate Liquidation Amount of Common Capital Securities [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	4,196,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust II [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	464,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust III [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	465,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust IV [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	465,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust V [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	774,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust VI [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	774,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust VII [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	774,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Greater Sacramento Bancorp Statutory Trust one [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	124,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Greater Sacramento Bancorp Statutory Trust Two [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	124,000
Aggregate Liquidation Amount of Common Capital Securities [Member] | Mission Oaks Statutory Trust One [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 232,000