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LOANS, Loan Summary (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | --- | ---
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | $ 7,368,327 | $ 7,415,952 |
Allowance for credit losses | (55,069) | (60,869) | $ (49,911)
Net loans | 7,313,258 | 7,355,083 |
Commercial Portfolio Segment [Member] | Business Lending [Member] |  |  |
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | 3,391,786 | 3,440,077 |
Allowance for credit losses | (27,042) | (28,190) | (19,426)
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] |  |  |
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | 2,409,373 |  |
Allowance for credit losses | (9,686) | (10,672) | (10,269)
Consumer Portfolio Segment [Member] | Consumer Mortgage [Member] |  |  |
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | 2,409,373 | 2,401,499 |
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] |  |  |
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | 1,029,335 | 1,021,885 |
Allowance for credit losses | (11,120) | (13,696) | (13,712)
Consumer Portfolio Segment [Member] | Consumer Direct [Member] |  |  |
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | 142,425 | 152,657 |
Allowance for credit losses | (2,682) | (3,207) | (3,255)
Consumer Portfolio Segment [Member] | Home Equity [Member] |  |  |
Loans receivable, net |  |  |
Gross loans, including deferred origination costs | 395,408 | 399,834 |
Allowance for credit losses | $ (1,543) | $ (2,222) | $ (2,129)

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