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LOANS HELD FOR INVESTMENT, NET - Credit Quality Indicators (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020 | Dec. 31, 2020
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Percentage of aggregate rental income |  |  | 50.00% |  |
Loans | $ 9,546,631 |  | $ 9,546,631 |  | $ 5,622,044
Criticized |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Sold amount | 50,700 | $ 0 | 54,600 | $ 7,100 |
One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 86,022 |  | 86,022 |  |
2020 | 100,125 |  | 100,125 |  |
2019 | 91,701 |  | 91,701 |  |
2018 | 92,641 |  | 92,641 |  |
2017 | 90,171 |  | 90,171 |  |
2016 and Prior | 174,052 |  | 174,052 |  |
Revolving | 55,975 |  | 55,975 |  |
Revolving-Term | 13,802 |  | 13,802 |  |
Total Loans | 704,489 |  | 704,489 |  |
One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 86,022 |  | 86,022 |  |
2020 | 100,125 |  | 100,125 |  |
2019 | 90,239 |  | 90,239 |  |
2018 | 91,137 |  | 91,137 |  |
2017 | 89,074 |  | 89,074 |  |
2016 and Prior | 160,866 |  | 160,866 |  |
Revolving | 55,128 |  | 55,128 |  |
Revolving-Term | 11,691 |  | 11,691 |  |
Total Loans | 684,282 |  | 684,282 |  |
One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2019 | 379 |  | 379 |  |
2018 | 915 |  | 915 |  |
2017 | 355 |  | 355 |  |
2016 and Prior | 5,299 |  | 5,299 |  |
Revolving | 847 |  | 847 |  |
Revolving-Term | 1,098 |  | 1,098 |  |
Total Loans | 8,893 |  | 8,893 |  |
One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2019 | 1,083 |  | 1,083 |  |
2018 | 589 |  | 589 |  |
2017 | 742 |  | 742 |  |
2016 and Prior | 7,887 |  | 7,887 |  |
Revolving-Term | 1,013 |  | 1,013 |  |
Total Loans | 11,314 |  | 11,314 |  |
Multifamily Residential and Residential Mixed-Use [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 234,199 |  | 234,199 |  |
2020 | 362,014 |  | 362,014 |  |
2019 | 552,409 |  | 552,409 |  |
2018 | 253,955 |  | 253,955 |  |
2017 | 455,259 |  | 455,259 |  |
2016 and Prior | 1,636,602 |  | 1,636,602 |  |
Revolving | 8,767 |  | 8,767 |  |
Total Loans | 3,503,205 |  | 3,503,205 |  |
Multifamily Residential and Residential Mixed-Use [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 234,199 |  | 234,199 |  |
2020 | 362,014 |  | 362,014 |  |
2019 | 516,988 |  | 516,988 |  |
2018 | 226,705 |  | 226,705 |  |
2017 | 407,607 |  | 407,607 |  |
2016 and Prior | 1,529,746 |  | 1,529,746 |  |
Revolving | 5,339 |  | 5,339 |  |
Total Loans | 3,282,598 |  | 3,282,598 |  |
Multifamily Residential and Residential Mixed-Use [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2017 | 18,329 |  | 18,329 |  |
2016 and Prior | 14,244 |  | 14,244 |  |
Total Loans | 32,573 |  | 32,573 |  |
Multifamily Residential and Residential Mixed-Use [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2019 | 35,421 |  | 35,421 |  |
2018 | 27,250 |  | 27,250 |  |
2017 | 29,323 |  | 29,323 |  |
2016 and Prior | 92,612 |  | 92,612 |  |
Revolving | 3,428 |  | 3,428 |  |
Total Loans | 188,034 |  | 188,034 |  |
Commercial Real Estate and Commercial Mixed-Use [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 410,562 |  | 410,562 |  |
2020 | 870,816 |  | 870,816 |  |
2019 | 598,147 |  | 598,147 |  |
2018 | 398,723 |  | 398,723 |  |
2017 | 400,592 |  | 400,592 |  |
2016 and Prior | 957,512 |  | 957,512 |  |
Revolving | 39,993 |  | 39,993 |  |
Revolving-Term | 4,986 |  | 4,986 |  |
Total Loans | 3,681,331 |  | 3,681,331 |  |
Commercial Real Estate and Commercial Mixed-Use [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 410,562 |  | 410,562 |  |
2020 | 865,541 |  | 865,541 |  |
2019 | 590,972 |  | 590,972 |  |
2018 | 351,435 |  | 351,435 |  |
2017 | 365,870 |  | 365,870 |  |
2016 and Prior | 912,770 |  | 912,770 |  |
Revolving | 39,993 |  | 39,993 |  |
Revolving-Term | 4,986 |  | 4,986 |  |
Total Loans | 3,542,129 |  | 3,542,129 |  |
Commercial Real Estate and Commercial Mixed-Use [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2020 | 4,229 |  | 4,229 |  |
2019 | 1,673 |  | 1,673 |  |
2018 | 4,851 |  | 4,851 |  |
2017 | 11,190 |  | 11,190 |  |
2016 and Prior | 11,444 |  | 11,444 |  |
Total Loans | 33,387 |  | 33,387 |  |
Commercial Real Estate and Commercial Mixed-Use [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2020 | 1,046 |  | 1,046 |  |
2019 | 5,502 |  | 5,502 |  |
2018 | 42,437 |  | 42,437 |  |
2017 | 23,532 |  | 23,532 |  |
2016 and Prior | 33,298 |  | 33,298 |  |
Total Loans | 105,815 |  | 105,815 |  |
ADC [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 61,748 |  | 61,748 |  |
2020 | 60,895 |  | 60,895 |  |
2019 | 81,000 |  | 81,000 |  |
2018 | 58,484 |  | 58,484 |  |
2017 | 8,807 |  | 8,807 |  |
2016 and Prior | 1,377 |  | 1,377 |  |
Revolving | 17,538 |  | 17,538 |  |
Revolving-Term | 613 |  | 613 |  |
Total Loans | 290,462 |  | 290,462 |  |
ADC [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 61,748 |  | 61,748 |  |
2020 | 60,895 |  | 60,895 |  |
2019 | 81,000 |  | 81,000 |  |
2018 | 43,906 |  | 43,906 |  |
2017 | 8,807 |  | 8,807 |  |
2016 and Prior | 1,279 |  | 1,279 |  |
Revolving | 17,538 |  | 17,538 |  |
Revolving-Term | 613 |  | 613 |  |
Total Loans | 275,786 |  | 275,786 |  |
ADC [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2018 | 1,078 |  | 1,078 |  |
Total Loans | 1,078 |  | 1,078 |  |
ADC [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2018 | 13,500 |  | 13,500 |  |
2016 and Prior | 98 |  | 98 |  |
Total Loans | 13,598 |  | 13,598 |  |
C&I |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 41,557 |  | 41,557 |  |
2020 | 557,766 |  | 557,766 |  |
2019 | 78,048 |  | 78,048 |  |
2018 | 70,415 |  | 70,415 |  |
2017 | 55,845 |  | 55,845 |  |
2016 and Prior | 30,797 |  | 30,797 |  |
Revolving | 495,152 |  | 495,152 |  |
Revolving-Term | 14,289 |  | 14,289 |  |
Total Loans | 1,343,869 |  | 1,343,869 |  |
C&I | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 41,557 |  | 41,557 |  |
2020 | 549,694 |  | 549,694 |  |
2019 | 63,141 |  | 63,141 |  |
2018 | 60,724 |  | 60,724 |  |
2017 | 40,088 |  | 40,088 |  |
2016 and Prior | 29,378 |  | 29,378 |  |
Revolving | 466,245 |  | 466,245 |  |
Revolving-Term | 7,067 |  | 7,067 |  |
Total Loans | 1,257,894 |  | 1,257,894 |  |
C&I | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2020 | 3,515 |  | 3,515 |  |
2019 | 291 |  | 291 |  |
2018 | 2,241 |  | 2,241 |  |
2017 | 643 |  | 643 |  |
2016 and Prior | 116 |  | 116 |  |
Revolving | 6,127 |  | 6,127 |  |
Revolving-Term | 2,637 |  | 2,637 |  |
Total Loans | 15,570 |  | 15,570 |  |
C&I | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2020 | 4,557 |  | 4,557 |  |
2019 | 14,419 |  | 14,419 |  |
2018 | 6,698 |  | 6,698 |  |
2017 | 3,185 |  | 3,185 |  |
2016 and Prior | 1,171 |  | 1,171 |  |
Revolving | 22,780 |  | 22,780 |  |
Revolving-Term | 4,585 |  | 4,585 |  |
Total Loans | 57,395 |  | 57,395 |  |
C&I | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2019 | 197 |  | 197 |  |
2018 | 752 |  | 752 |  |
2017 | 11,929 |  | 11,929 |  |
2016 and Prior | 132 |  | 132 |  |
Total Loans | 13,010 |  | 13,010 |  |
Real estate |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 8,179,487 |  | 8,179,487 |  | 4,978,195
Real estate | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 4,681,059
Real estate | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 83,761
Real estate | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 213,375
Real estate | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Real estate | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 704,489 |  | 704,489 |  | 184,989
Real estate | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 183,293
Real estate | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Real estate | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 1,696
Real estate | One- to-Four Family Residential, Including Condominium and Cooperative Apartment [Member] | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Real estate | Multifamily Residential and Residential Mixed-Use [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 3,503,205 |  | 3,503,205 |  | 2,758,743
Real estate | Multifamily Residential and Residential Mixed-Use [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 2,523,258
Real estate | Multifamily Residential and Residential Mixed-Use [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 56,400
Real estate | Multifamily Residential and Residential Mixed-Use [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 179,085
Real estate | Multifamily Residential and Residential Mixed-Use [Member] | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Real estate | Commercial Real Estate and Commercial Mixed-Use [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 3,681,331 |  | 3,681,331 |  | 1,878,167
Real estate | Commercial Real Estate and Commercial Mixed-Use [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 1,831,712
Real estate | Commercial Real Estate and Commercial Mixed-Use [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 13,861
Real estate | Commercial Real Estate and Commercial Mixed-Use [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 32,594
Real estate | Commercial Real Estate and Commercial Mixed-Use [Member] | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Real estate | ADC [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 290,462 |  | 290,462 |  | 156,296
Real estate | ADC [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 142,796
Real estate | ADC [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 13,500
Real estate | ADC [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Real estate | ADC [Member] | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 0
Commercial and industrial ("C&I") loans |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 1,343,869 |  | 1,343,869 |  | 641,533
Commercial and industrial ("C&I"), including SBA and PPP loans |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 1,343,869 |  | 1,343,869 |  | 641,533
Commercial and industrial ("C&I"), including SBA and PPP loans | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 613,691
Commercial and industrial ("C&I"), including SBA and PPP loans | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 2,131
Commercial and industrial ("C&I"), including SBA and PPP loans | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 13,315
Commercial and industrial ("C&I"), including SBA and PPP loans | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 12,396
Real Estate Loans and C & I Loans [Member] |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 5,619,728
Real Estate Loans and C & I Loans [Member] | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 5,294,750
Real Estate Loans and C & I Loans [Member] | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 85,892
Real Estate Loans and C & I Loans [Member] | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 226,690
Real Estate Loans and C & I Loans [Member] | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 12,396
Other loans |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 23,275 |  | 23,275 |  | 2,316
2021 | 834,088 |  | 834,088 |  |
2020 | 1,951,616 |  | 1,951,616 |  |
2019 | 1,401,305 |  | 1,401,305 |  |
2018 | 874,218 |  | 874,218 |  |
2017 | 1,010,674 |  | 1,010,674 |  |
2016 and Prior | 2,800,340 |  | 2,800,340 |  |
Revolving | 617,425 |  | 617,425 |  |
Revolving-Term | 33,690 |  | 33,690 |  |
Total Loans | 9,523,356 |  | 9,523,356 |  |
Other loans | Credit Risk Profile |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 23,275 |  | 23,275 |  |
Other loans | Performing |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | 2,315
Other loans | Performing | Credit Risk Profile |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 23,183 |  | 23,183 |  |
Other loans | Non-Accrual |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans |  |  |  |  | $ 1
Other loans | Non-Accrual | Credit Risk Profile |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
Loans | 92 |  | 92 |  |
Other loans | Pass |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2021 | 834,088 |  | 834,088 |  |
2020 | 1,938,269 |  | 1,938,269 |  |
2019 | 1,342,340 |  | 1,342,340 |  |
2018 | 773,907 |  | 773,907 |  |
2017 | 911,446 |  | 911,446 |  |
2016 and Prior | 2,634,039 |  | 2,634,039 |  |
Revolving | 584,243 |  | 584,243 |  |
Revolving-Term | 24,357 |  | 24,357 |  |
Total Loans | 9,042,689 |  | 9,042,689 |  |
Other loans | Special Mention |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2020 | 7,744 |  | 7,744 |  |
2019 | 2,343 |  | 2,343 |  |
2018 | 9,085 |  | 9,085 |  |
2017 | 30,517 |  | 30,517 |  |
2016 and Prior | 31,103 |  | 31,103 |  |
Revolving | 6,974 |  | 6,974 |  |
Revolving-Term | 3,735 |  | 3,735 |  |
Total Loans | 91,501 |  | 91,501 |  |
Other loans | Substandard |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2020 | 5,603 |  | 5,603 |  |
2019 | 56,425 |  | 56,425 |  |
2018 | 90,474 |  | 90,474 |  |
2017 | 56,782 |  | 56,782 |  |
2016 and Prior | 135,066 |  | 135,066 |  |
Revolving | 26,208 |  | 26,208 |  |
Revolving-Term | 5,598 |  | 5,598 |  |
Total Loans | 376,156 |  | 376,156 |  |
Other loans | Doubtful |  |  |  |  |
Credit Risk Profile of Real Estate Loans [Abstract] |  |  |  |  |
2019 | 197 |  | 197 |  |
2018 | 752 |  | 752 |  |
2017 | 11,929 |  | 11,929 |  |
2016 and Prior | 132 |  | 132 |  |
Total Loans | $ 13,010 |  | $ 13,010 |  |

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