SECURITIES (Details)		3 Months Ended		9 Months Ended
	Oct. 01, 2022 USD ($)	Sep. 30, 2023 USD ($) security	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) security	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) security
Debt securities available for sale		$ 66,527,000		$ 66,527,000		$ 73,536,000
Unrealized Loss	$ 46,800,000
Transfer from available for sale	0
Carrying value of pledged assets		174,300,000		174,300,000		102,300,000
Equity securities		978,000		978,000		1,056,000
Held-to-maturity securities		$ 202,646,000		$ 202,646,000		$ 209,565,000
Securities in unrealized loss position | security		55		55		57
Realized gain (loss) on equity securities		$ (14,000)	$ (30,000)	$ (78,000)	$ (110,000)
Proceeds from sales or calls of securities		0	6,137,000	0	23,271,000
Merger with Banc of California, Inc
Subordinated debt		1,500,000		1,500,000
Amount in investment agreements to issue		$ 400,000,000.0		$ 400,000,000.0
Obligations of U.S. Government Agencies and Corporations
Investment portfolio percentage		16.00%		16.00%
Debt securities available for sale		$ 13,727,000		$ 13,727,000		$ 13,705,000
Held-to-maturity securities		$ 29,283,000		$ 29,283,000		$ 28,600,000
Securities in unrealized loss position | security		3		3		3
Securities in unrealized loss position | security		10		10
U.S. Government Sponsored Agencies
Transfer of securities from available for sale to held to maturity	28,400,000
Obligations of State and Political Subdivisions
Investment portfolio percentage		3.00%		3.00%
Debt securities available for sale		$ 6,713,000		$ 6,713,000		$ 7,679,000
Debt Securities Maturity Term				5 years
Securities in unrealized loss position | security		9		9		11
Corporate Debt Securities
Investment portfolio percentage		5.00%		5.00%
Debt securities available for sale		$ 13,374,000		$ 13,374,000		$ 15,341,000
Securities in unrealized loss position | security		9		9		9
Mortgage-Backed Securities
Investment portfolio percentage		76.00%		76.00%
Transfer of securities from available for sale to held to maturity	$ 183,900,000
Held-to-maturity securities		$ 173,363,000		$ 173,363,000
Securities in unrealized loss position | security		34		34		34
Securities in unrealized loss position | security		84		84
Federal Farm Credit Bank
Available-for-sale and held-to-maturity securities greater than 10% of stockholders equity		$ 10,800,000		$ 10,800,000		$ 10,900,000
Pennsylvania Housing Finance
Available-for-sale and held-to-maturity securities greater than 10% of stockholders equity		5,100,000		5,100,000		$ 6,100,000
Subordinated Debt
Debt security			$ 24,700,000		24,700,000
Realized gain (loss) on debt securities					$ (1,500,000)
Subordinated Debt | Pacific Western Bank
Debt securities available for sale		$ 1,500,000		$ 1,500,000