FAIR VALUE - RECURRING BASIS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Financial assets:
Available-for-sale debt securities, Fair Value	$ 543,859		$ 471,355
Mortgage loans held for sale, at fair value	39,384	$ 11,313	19,224	$ 8,971
Consumer loans held for sale	3,431		598
Consumer loans receivable held for investment	827		998
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	2,807		3,188
U.S. Treasury securities and U.S. Government agencies
Financial assets:
Available-for-sale debt securities, Fair Value	169,292		134,640
Private label mortgage backed security
Financial assets:
Available-for-sale debt securities, Fair Value	3,249		3,495
Mortgage backed securities - residential
Financial assets:
Available-for-sale debt securities, Fair Value	297,722		255,847
Collateralized mortgage obligations
Financial assets:
Available-for-sale debt securities, Fair Value	59,881		63,371
Corporate bonds
Financial assets:
Available-for-sale debt securities, Fair Value	9,615		10,002
Trust preferred security
Financial assets:
Available-for-sale debt securities, Fair Value	4,100		4,000
Freddie Mac preferred stock
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	294		714
Community Reinvestment Act mutual fund
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	2,513		2,474
Recurring basis
Financial assets:
Available-for-sale debt securities, Fair Value	543,859		471,355
Mortgage loans held for sale, at fair value	39,384		19,224
Consumer loans held for investment	827
Consumer loans held for sale	3,431		598
Consumer loans receivable held for investment			998
Rate lock loan commitments	4,568		789
Mandatory forward contracts	2,826
Interest rate swap agreements	14,013		5,062
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	2,807		3,188
Financial Liabilities:
Mandatory forward contracts			131
Interest rate swap agreements	14,249		5,166
Transfers between Level 1, 2 or 3	0	$ 0
Recurring basis | U.S. Treasury securities and U.S. Government agencies
Financial assets:
Available-for-sale debt securities, Fair Value	169,292		134,640
Recurring basis | Private label mortgage backed security
Financial assets:
Available-for-sale debt securities, Fair Value	3,249		3,495
Recurring basis | Mortgage backed securities - residential
Financial assets:
Available-for-sale debt securities, Fair Value	297,722		255,847
Recurring basis | Collateralized mortgage obligations
Financial assets:
Available-for-sale debt securities, Fair Value	59,881		63,371
Recurring basis | Corporate bonds
Financial assets:
Available-for-sale debt securities, Fair Value	9,615		10,002
Recurring basis | Trust preferred security
Financial assets:
Available-for-sale debt securities, Fair Value	4,100		4,000
Recurring basis | Freddie Mac preferred stock
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	294		714
Recurring basis | Community Reinvestment Act mutual fund
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	2,513		2,474
Recurring basis | Fair Value, Inputs, Level 1
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	2,513		2,474
Recurring basis | Fair Value, Inputs, Level 1 | Community Reinvestment Act mutual fund
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	2,513		2,474
Recurring basis | Fair Value, Inputs, Level 2
Financial assets:
Available-for-sale debt securities, Fair Value	536,510		463,860
Mortgage loans held for sale, at fair value	39,384		19,224
Rate lock loan commitments	4,568		789
Mandatory forward contracts	2,826
Interest rate swap agreements	14,013		5,062
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	294		714
Financial Liabilities:
Mandatory forward contracts			131
Interest rate swap agreements	14,249		5,166
Recurring basis | Fair Value, Inputs, Level 2 | U.S. Treasury securities and U.S. Government agencies
Financial assets:
Available-for-sale debt securities, Fair Value	169,292		134,640
Recurring basis | Fair Value, Inputs, Level 2 | Mortgage backed securities - residential
Financial assets:
Available-for-sale debt securities, Fair Value	297,722		255,847
Recurring basis | Fair Value, Inputs, Level 2 | Collateralized mortgage obligations
Financial assets:
Available-for-sale debt securities, Fair Value	59,881		63,371
Recurring basis | Fair Value, Inputs, Level 2 | Corporate bonds
Financial assets:
Available-for-sale debt securities, Fair Value	9,615		10,002
Recurring basis | Fair Value, Inputs, Level 2 | Freddie Mac preferred stock
Equity securities with readily determinable fair value:
Equity securities with readily determinable fair value	294		714
Recurring basis | Fair Value, Inputs, Level 3
Financial assets:
Available-for-sale debt securities, Fair Value	7,349		7,495
Consumer loans held for investment	827
Consumer loans held for sale	3,431		598
Consumer loans receivable held for investment			998
Recurring basis | Fair Value, Inputs, Level 3 | Private label mortgage backed security
Financial assets:
Available-for-sale debt securities, Fair Value	3,249		3,495
Recurring basis | Fair Value, Inputs, Level 3 | Trust preferred security
Financial assets:
Available-for-sale debt securities, Fair Value	$ 4,100		$ 4,000