EARNINGS PER SHARE (Details) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended
		Aug. 14, 2019	Jun. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) $ / shares shares
EARNINGS PER SHARE
Net income applicable to common stock | $			$ 10,575	$ 4,781	$ 15,299	$ 6,848
Average number of common shares outstanding			58,418,021	58,471,680	58,418,021	58,466,373
Less: Average unallocated ESOP shares			(3,967,875)	(1,767,383)	(3,996,715)	(1,780,632)
Average number of common shares outstanding used to calculate basic earnings per common share	[1]		54,450,146	56,704,297	54,421,306	56,685,741
Average number of common shares outstanding used to calculate diluted earnings per common share	[1]		54,450,146	56,704,297	54,421,306	56,685,741
Basic | $ / shares	[1]		$ 0.19	$ 0.08	$ 0.28	$ 0.12
Diluted | $ / shares	[1]		$ 0.19	$ 0.08	$ 0.28	$ 0.12
Stock conversion ratio		1.795431	1.795431	1.795431	1.795431	1.795431
Stock Options
EARNINGS PER SHARE
Antidilutive securities excluded from computation of earnings per share			2,169,243	2,240,307	2,169,243	2,240,307

[1] Share amounts related to periods prior to the August 14, 2019 closing of the conversion offering have been restated to give retroactive recognition to the 1.795431 exchange ratio applied in the conversion offering (see Note 1).