| transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +77 | 
            +0.15% | 
            $0.00 | 
            53.1K | 
            Mar 23, 2021 | 
            Direct | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            -1.23K | 
            -2.32% | 
            $0.00 | 
            51.9K | 
            Mar 23, 2021 | 
            Direct | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            -84 | 
            -1.18% | 
            $0.00 | 
            7.06K | 
            Oct 12, 2021 | 
            Direct | 
            F1, F2, F3 | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +77 | 
            +1.6% | 
            $0.00 | 
            4.89K | 
            Mar 23, 2021 | 
            Shares held by reporting person?s wife | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +231 | 
            +17.19% | 
            $0.00 | 
            1.58K | 
            Mar 23, 2021 | 
            Shares held as trustee for grandchild (trust 1) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +231 | 
            +25.78% | 
            $0.00 | 
            1.13K | 
            Mar 23, 2021 | 
            Shares held as trustee for grandchild (trust 2) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +231 | 
            +30.2% | 
            $0.00 | 
            996 | 
            Mar 23, 2021 | 
            Shares held as trustee for grandchild (trust 3) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +231 | 
            +39.42% | 
            $0.00 | 
            817 | 
            Mar 23, 2021 | 
            Shares held as trustee for grandchild (trust 4) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +231 | 
            +62.26% | 
            $0.00 | 
            602 | 
            Mar 23, 2021 | 
            Shares held as trustee for grandchild (trust 5) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +154 | 
            +102.67% | 
            $0.00 | 
            304 | 
            Mar 23, 2021 | 
            Shares held as trustee for grandchild (trust 6) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +84 | 
            +27.63% | 
            $0.00 | 
            388 | 
            Oct 12, 2021 | 
            Shares held as trustee for grandchild (trust 6) | 
             | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Gift | 
            $0 | 
            +252 | 
             | 
            $0.00 | 
            252 | 
            Oct 12, 2021 | 
            Shares held as trustee for grandchild (trust 7) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            36.4K | 
            Dec 31, 2021 | 
            NewMarket Savings Plan | 
            F4 | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            161K | 
            Dec 31, 2021 | 
            2020 GRAT | 
            F1 | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            51K | 
            Dec 31, 2021 | 
            2021 GRAT #1 | 
            F2 | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            50K | 
            Dec 31, 2021 | 
            2021 GRAT #2 | 
            F3 | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            206K | 
            Dec 31, 2021 | 
            Shares held as co-trustee fbo (among others reporting Floyd D. Gottwald) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            6.89K | 
            Dec 31, 2021 | 
            Shares held as co-trustee fbo children dtd. 12/16/91 | 
             |