Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Mar. 29, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	NANOPHASE TECHNOLOGIES Corp
Entity Central Index Key	0000883107
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Trading Symbol	NANX
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filer	No
Entity Reporting Status Current	Yes
Entity Small Business	true
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth	false
Entity Shell Company	false
Entity Public Float			$ 32,493,881
Entity Common Stock, Shares Outstanding		33,911,792
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2018