Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 12, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	000-23486
Entity Registrant Name	NN, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	62-1096725
Entity Address, Address Line One	6210 Ardrey Kell Road, Suite 600
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28277
City Area Code	980
Local Phone Number	264-4300
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 89
Entity Common Stock, Shares Outstanding		42,791,476
Documents Incorporated by Reference	Portions of the Proxy Statement with respect to the 2021 Annual Meeting of Stockholders are incorporated by reference in Part III, Items 10 to 14 of this Annual Report on Form 10-K as indicated herein. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2020.
Entity Central Index Key	0000918541
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Filer Category	Accelerated Filer
Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01
Trading Symbol	NNBR
Security Exchange Name	NASDAQ
Preferred Stock Purchase Rights
Entity Information [Line Items]
Title of 12(b) Security	Preferred Stock Purchase Rights
Security Exchange Name	NASDAQ
No Trading Symbol Flag	true