LOANS HELD FOR INVESTMENT, NET - Past Due Status (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	$ 10,773,428	$ 10,566,831
Total	10,766,837	10,566,831
Non-accrual	29,099	34,237
Accruing Loans 90 Days or More Past Due	0	0
Non-accrual	29,099	34,237
Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	42,366	58,496
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	11,977	23,517
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	1,290	742
Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	10,724,471	10,508,335
Total real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	9,694,144	9,487,440
Non-accrual	14,432	12,192
Non-accrual	14,432	12,192
Total real estate loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	22,374	31,884
Total real estate loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	7,661	19,692
Total real estate loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	281
Total real estate loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	9,671,770	9,455,556
One-to-four family residential and cooperative/condominium apartment
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	887,555	773,321
Non-accrual	3,248	3,203
Non-accrual	3,248	3,203
One-to-four family residential and cooperative/condominium apartment | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	7,392	3,889
One-to-four family residential and cooperative/condominium apartment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	4,071	686
One-to-four family residential and cooperative/condominium apartment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	73
One-to-four family residential and cooperative/condominium apartment | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	880,163	769,432
Multifamily residential and residential mixed-use
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	4,017,176	4,026,826
Multifamily residential and residential mixed-use | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments		4,817
Multifamily residential and residential mixed-use | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments		4,817
Multifamily residential and residential mixed-use | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	4,017,176	4,022,009
Commercial real estate ("CRE")
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	4,620,900	4,457,630
Non-accrual	10,527	8,332
Non-accrual	10,527	8,332
Commercial real estate ("CRE") | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	13,895	22,521
Commercial real estate ("CRE") | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	3,160	14,189
Commercial real estate ("CRE") | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	208
Commercial real estate ("CRE") | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	4,607,005	4,435,109
Acquisition, development, and construction ("ADC")
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	168,513	229,663
Non-accrual	657	657
Non-accrual	657	657
Acquisition, development, and construction ("ADC") | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	1,087	657
Acquisition, development, and construction ("ADC") | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	430
Acquisition, development, and construction ("ADC") | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	167,426	229,006
Commercial and Industrial ("C&I") Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	1,066,938	1,071,712
Non-accrual	14,667	21,946
Non-accrual	14,667	21,946
Commercial and Industrial ("C&I") Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	19,992	26,248
Commercial and Industrial ("C&I") Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	4,316	3,561
Commercial and Industrial ("C&I") Loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	1,009	741
Commercial and Industrial ("C&I") Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	1,046,946	1,045,464
Other Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	5,755	7,679
Non-accrual		99
Non-accrual		99
Other Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments		364
Other Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments		264
Other Loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments		1
Other Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans, net of fair value hedge basis point adjustments	$ 5,755	$ 7,315