PARENT COMPANY FINANCIAL INFORMATION (Schedule of condensed balance sheet of Southern National Bancorp of Virginia, Inc.) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash	$ 31,928	$ 28,611
Other assets	20,827	19,057
Total assets	2,722,170	2,701,295
Liabilities [Abstract]
Junior subordinated debt - long term	9,632	9,584
Senior subordinated notes-long term	47,051	47,089
Other liabilities	20,536	16,671
Total liabilities	2,344,929	2,353,005
Stockholders' equity:
Common stock	241	240
Additional paid in capital	306,755	305,654
Retained earnings	69,462	44,985
Accumulated other comprehensive income (loss)	783	(2,589)
Total stockholders' equity	377,241	348,290	$ 322,772	$ 126,344
Total liabilities and stockholders' equity	2,722,170	2,701,295
Southern National | Reportable Legal Entities
ASSETS
Cash	2,707	1,393
Investment in subsidiary	423,591	397,063
Other assets	8,128	7,174
Total assets	434,426	405,630
Liabilities [Abstract]
Junior subordinated debt - long term	9,632	9,584
Senior subordinated notes-long term	47,051	47,089
Other liabilities	502	667
Total liabilities	57,185	57,340
Stockholders' equity:
Common stock	241	240
Additional paid in capital	306,755	305,654
Retained earnings	69,462	44,985
Accumulated other comprehensive income (loss)	783	(2,589)
Total stockholders' equity	377,241	348,290
Total liabilities and stockholders' equity	$ 434,426	$ 405,630