ACQUISITIONS (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Blue Hills Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Net interest income after provision for loan losses	$ 408,918	$ 371,264
Net income	$ 129,385	146,178
MNB Bancorp [Member]
Business Acquisition [Line Items]
Net interest income after provision for loan losses		304,049	$ 267,104
Net income		$ 122,310	$ 88,518