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BORROWINGS AND LONG-TERM DEBT - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 30, 2027	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Debt Instrument [Line Items]
Par Value		$ 222,857
Carrying value		190,123	$ 0	$ 0
HomeStreet Statutory Trust Subordinated Debt Securities I \| Subordinated Debt
Debt Instrument [Line Items]
Par Value		5,155
Carrying value		$ 4,048
Basis spread on variable rate		1.96%
HomeStreet Statutory Trust Subordinated Debt Securities II \| Subordinated Debt
Debt Instrument [Line Items]
Par Value		$ 20,619
Carrying value		$ 15,773
Basis spread on variable rate		1.76%
HomeStreet Statutory Trust Subordinated Debt Securities III \| Subordinated Debt
Debt Instrument [Line Items]
Par Value		$ 20,619
Carrying value		$ 15,516
Basis spread on variable rate		1.63%
HomeStreet Statutory Trust Subordinated Debt Securities IV \| Subordinated Debt
Debt Instrument [Line Items]
Par Value		$ 15,464
Carrying value		$ 11,729
Basis spread on variable rate		1.94%
Senior Notes 6.50% Due 2026 \| Senior Notes
Debt Instrument [Line Items]
Par Value		$ 65,000
Carrying value		$ 64,608
Rate		6.50%
3.5% Subordinated Notes Due 2032 \| Subordinated Debt
Debt Instrument [Line Items]
Par Value		$ 96,000
Carrying value		$ 78,449
Rate		3.50%
3.5% Subordinated Notes Due 2032 \| Subordinated Debt \| Forecast
Debt Instrument [Line Items]
Basis spread on variable rate	2.15%