JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES - Schedule of Trusts (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Amount	$ 61,857	$ 61,857
Trust Preferred Securities Subject to Mandatory Redemption | Luther Burbank Statutory Trust I | Trusts
Debt Instrument [Line Items]
Amount	$ 41,238	$ 41,238
Rate	1.69%	3.27%
Trust Preferred Securities Subject to Mandatory Redemption | Luther Burbank Statutory Trust I | Trusts | LIBOR
Debt Instrument [Line Items]
Rate Index (Quarterly Reset)	1.38%
Trust Preferred Securities Subject to Mandatory Redemption | Luther Burbank Statutory Trust II | Trusts
Debt Instrument [Line Items]
Amount	$ 20,619	$ 20,619
Rate	1.93%	3.51%
Trust Preferred Securities Subject to Mandatory Redemption | Luther Burbank Statutory Trust II | Trusts | LIBOR
Debt Instrument [Line Items]
Rate Index (Quarterly Reset)	1.62%