PARENT COMPANY FINANCIAL INFORMATION (Schedule of condensed statements of cash flows information of Southern National Bancorp of Virginia, Inc.) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net income	$ 33,167	$ 33,691	$ 2,425
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Other, net	(2,203)	213	6,069
Net cash and cash equivalents (used in) operating activities	36,764	41,440	24,587
Investing activities:
Net cash and cash equivalents provided by investing activities	(5,018)	(93,696)	(62,006)
Financing activities:
Issuance of subordinated notes, net of cost			26,075
Issuance of common stock	670	443	555
Dividend payment on common stock	(8,690)	(7,688)	(5,798)
Net cash and cash equivalents provided by (used in) financing activities	(28,429)	55,404	15,490
Increase (decrease) in cash and cash equivalents	3,317	3,148	(21,929)
Cash and cash equivalents at beginning of period	28,611	25,463	47,392
Cash and cash equivalents at end of period	31,928	28,611	25,463
Southern National | Reportable Legal Entities
Operating activities:
Net income	33,167	33,691	2,425
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Equity in undistributed net income of subsidiaries	(36,467)	(37,006)	(6,963)
Other, net	(666)	(582)	4,046
Net cash and cash equivalents (used in) operating activities	(3,966)	(3,897)	(492)
Investing activities:
Increase in investment in subsidiary			(22,000)
Dividend from subsidiary	13,300	8,000	4,900
Acquisition of Eastern Virginia Bankshares, Inc.			(10)
Net cash and cash equivalents provided by investing activities	13,300	8,000	(17,110)
Financing activities:
Issuance of subordinated notes, net of cost			26,075
Issuance of common stock	670	443	1,004
Dividend payment on common stock	(8,690)	(7,688)	(5,798)
Net cash and cash equivalents provided by (used in) financing activities	(8,020)	(7,245)	21,281
Increase (decrease) in cash and cash equivalents	1,314	(3,142)	3,679
Cash and cash equivalents at beginning of period	1,393	4,535	856
Cash and cash equivalents at end of period	$ 2,707	$ 1,393	$ 4,535