Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 10, 2021
Cover [Abstract]
Entity Registrant Name	Deep Down, Inc.
Entity Central Index Key	0001110607
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth	false
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Incorporation State Country Code	NV
Entity File Number	000-30351
Entity Common Stock, Shares Outstanding		12,388,865
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021