| transaction | 
            NEU | 
            Common Stock | 
            Award | 
            $0 | 
            +1.18K | 
            +5.21% | 
            $0.00 | 
            23.7K | 
            Feb 23, 2023 | 
            Direct | 
            F1 | 
          
          
            | transaction | 
            NEU | 
            Common Stock | 
            Tax liability | 
            -$123K | 
            -364 | 
            -1.54% | 
            $338.85 | 
            23.3K | 
            Feb 23, 2023 | 
            Direct | 
            F2 | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            37.5K | 
            Feb 23, 2023 | 
            NewMarket Savings Plan | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            5.09K | 
            Feb 23, 2023 | 
            Shares held by reporting person's wife | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            2.17K | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 1) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            1.72K | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 2) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            1.49K | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 3) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            1.41K | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 4) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            1.09K | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 5 | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            880 | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 6) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            843 | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 7) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            501 | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 8) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            297 | 
            Feb 23, 2023 | 
            Shares held as trustee for grandchild (trust 9) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            46.4K | 
            Feb 23, 2023 | 
            Shares held as co-trustee fbo (among others reporting Floyd D. Gottwald) | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            6.89K | 
            Feb 23, 2023 | 
            Shares held as co-trustee fbo children dtd. 12/16/1991 | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            79.7K | 
            Feb 23, 2023 | 
            2020 GRAT | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            27.6K | 
            Feb 23, 2023 | 
            2021 GRAT #1 | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            35.6K | 
            Feb 23, 2023 | 
            2021 GRAT #2 | 
             | 
          
          
            | holding | 
            NEU | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            100K | 
            Feb 23, 2023 | 
            2022 GRAT | 
             |