XML 24 R1.htm IDEA: XBRL DOCUMENT v3.20.1
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Feb. 28, 2020
Jun. 28, 2019
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Trading Symbol NL    
Entity Registrant Name NL INDUSTRIES INC    
Entity Central Index Key 0000072162    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   48,755,734  
Entity Public Float     $ 30.5
Title of 12(b) Security Common stock    
Security Exchange Name NYSE    
Entity File Number 1-640    
Entity Incorporation, State or Country Code NJ    
Entity Tax Identification Number 13-5267260    
Entity Address, Address Line One 5430 LBJ Freeway, Suite 1700    
Entity Address, City or Town Dallas    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 75240-2620    
City Area Code (972)    
Local Phone Number 233-1700    
Document Annual Report true    
Document Transition Report false    
Documents Incorporated by Reference

The information required by Part III is incorporated by reference from the Registrant’s definitive proxy statement to be filed with the Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this report.