| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | NEWMARKET CORPORATION |
| Entity Central Index Key | 0001282637 |
| Pay vs Performance Disclosure Unit_pure in Thousands | 12 Months Ended | ||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | |
| Pay vs Performance Disclosure [Table] | |||
| Pay vs Performance [Table Text Block] | Pay versus Performance The following table shows the past three fiscal years’ total compensat io Fiscal Year 2022 Pay versus Performance Table Year Summary compensation table total for CEO (1) ($) Compensation actually paid to (3) ($) Average summary compensation table total for other NEOs (2) ($) Average compensation actually paid to other NEOs (3) ($) Total shareholder return (4) ($) Peer group total shareholder return (4) ($) Net income (in ($) Operating Profit (5) (in thousands) ($) 2022 2,098,436 2,185,637 1,157,780 1,210,032 68.64 110.83 279,538 363,000 2021 2,469,929 2,017,197 1,280,518 1,089,491 73.56 148.99 190,908 266,000 2020 3,149,426 1,847,089 1,452,162 905,376 83.52 117.89 270,568 319,000 (1) The amounts in this column reflect the Summary Compensation Table totals for Mr. Gottwald for fiscal years 2022, 2021 and 2020. (2) The amounts in this column reflect the average Summary Compensation Table totals for our non-CEO NEOs. For 2022 and 2021 this includes Mrs. Harm, Messrs. Paliotti, Hazelgrove and Jewett. For 2020, this includes Mrs. Harm, Messrs. Paliotti, Hazelgrove and Rudolph M. West. (3) SEC rules require certain adjustments be made to the Summary Compensation Table totals to determine compensation “actually paid” as reported in the Pay versus Performance table. The following tables detail these adjustments: Year Executives Summary Compensation Table Total ($) Deduct Reported Change in Actuarial Present Value of Pension Benefits (a) ($) Add Pension Benefit Adjustments (b) ($) Deduct Reported Value of Equity Awards (c) ($) Add Equity Award Adjustments (d) ($) Compensation Actually Paid ($) 2022 CEO 2,098,436 0 163,143 250,428 182,154 2,185,637 Other NEOs 1,157,780 0 94,788 193,470 150,934 1,210,032 2021 CEO 2,469,929 528,260 223,648 258,096 109,976 2,017,197 Other NEOs 1,280,518 193,093 93,964 198,990 107,362 1,089,491 2020 CEO 3,149,426 1,132,717 258,645 253,766 (174,499 ) 1,847,089 Other NEOs 1,452,162 383,722 109,136 195,565 (75,635 ) 905,376 (a) The amounts in this column represent the amounts reported in the “Change in Pension Value and Non-Qualified Deferred Compensation Earnings” column of the Summary Compensation Table for each appliable year. (b) The total pension benefit adjustments for each applicable year include the aggregate of two components: (i) the actuarially determined service cost for services rendered by the executive during the applicable year (the “service cost”); and (ii) the entire cost of benefits granted in a plan amendment (or initiation) during the applicable year that are attributed by the benefit formula to services rendered in periods prior to the plan amendment or initiation (the “prior service cost”), in each case, calculated in accordance with U.S. GAAP. The amounts deducted or added in calculating the pension benefit adjustments are as follows: Year Executives Service Cost ($) Prior Service Cost ($) Total Pension Value Adjustment ($) 2022 CEO 163,143 0 163,143 Other NEOs 94,788 0 94,788 2021 CEO 223,648 0 223,648 Other NEOs 93,694 0 93,694 2020 CEO 258,645 0 258,645 Other NEOs 109,136 0 109,136 (c) The amounts in this column represent the grant date fair value of equity awards as reported in the “Stock Awards” column of the Summary Compensation Table for each applicable year. (d) The equity award adjustments for each applicable year include the addition (or subtraction, as applicable) of the following: (i) the year-end fair value of any equity awards granted in the applicable year that are outstanding and unvested as of the end of the year; (ii) the amount of change in fair value as of the end of the applicable year (from the end of the prior fiscal year) of any awards granted in prior years that are outstanding and unvested as of the end of the applicable year; (iii) for awards that are granted and vest in the same applicable year, the fair value as of the vesting date; (iv) for awards granted in prior years that vest in the applicable year, the amount equal to the change in fair value as of the vesting date (from the end of the prior fiscal year); (v) for awards granted in prior years that are determined to fail to meet the applicable vesting conditions during the applicable year, a deduction for the amount equal to the fair value at the end of the prior fiscal year; and (vi) the dollar value of any dividends or other earnings paid on equity awards in the applicable year prior to the vesting date that are not otherwise reflected in the fair value of such award or included in any other component of total compensation for the applicable year. The amounts deducted or added in calculating the equity award adjustments are as follows: Year Executive Year end fair value of equity awards granted during the year ($) Year over year change in fair value of outstanding and unvested equity awards ($) Fair value as of vesting date of equity awards granted and vested in the year ($) Year over year change in fair value of equity awards granted in prior years that vested in the year ($) Fair value at the end of the prior year of equity awards that failed to meet vesting conditions in the year ($) Value of dividends or other earnings paid on stock or option awards reflected in fair value or total compensation Total equity award adjustments ($) 2022 CEO 248,266 (96,885) 0 0 0 30,773 182,154 Other NEOs 191,799 (59,261) 0 0 0 18,396 150,934 2021 CEO 224,482 (133,924) 0 0 0 19,418 109,976 Other NEOs 173,074 (76,117) 0 0 0 10,406 107,362 2020 CEO 242,957 (158,814) 0 (258,642) 0 0 (174,499) Other NEOs 188,192 (110,089) 0 (153,738) 0 0 (75,635) (4) Total shareholder return (TSR) is determined based on the value of an initial fixed investment of $100. The peer group TSR represents cumulative, weighted TSR of the S&P 1500 Specialty Chemicals Index. (5) The 2022 operating profit of approximately $363 million is based on our 2022 operating profit (calculated in accordance with GAAP) of $355 million, excluding a charge of $8 million for the bonus expense. The 2021 operating profit of approximately $266 million is based on our 2021 operating profit (calculated in accordance with GAAP) of $258 million, excluding a charge of $8 million for the bonus expense. The 2020 operating profit of approximately $319 million is based on our 2020 operating profit (calculated in accordance with GAAP) of $312 million, excluding a charge of $7 million for the bonus expense. | ||
| Company Selected Measure Name | operating profit | ||
| Named Executive Officers, Footnote [Text Block] | The amounts in this column reflect the average Summary Compensation Table totals for our non-CEO NEOs. For 2022 and 2021 this includes Mrs. Harm, Messrs. Paliotti, Hazelgrove and Jewett. For 2020, this includes Mrs. Harm, Messrs. Paliotti, Hazelgrove and Rudolph M. West. | ||
| Peer Group Issuers, Footnote [Text Block] | The peer group TSR represents cumulative, weighted TSR of the S&P 1500 Specialty Chemicals Index | ||
| PEO Total Compensation Amount | $ 2,098,436 | $ 2,469,929 | $ 3,149,426 |
| PEO Actually Paid Compensation Amount | $ 2,185,637 | 2,017,197 | 1,847,089 |
| Adjustment To PEO Compensation, Footnote [Text Block] | SEC rules require certain adjustments be made to the Summary Compensation Table totals to determine compensation “actually paid” as reported in the Pay versus Performance table. The following tables detail these adjustments: Year Executives Summary Compensation Table Total ($) Deduct Reported Change in Actuarial Present Value of Pension Benefits (a) ($) Add Pension Benefit Adjustments (b) ($) Deduct Reported Value of Equity Awards (c) ($) Add Equity Award Adjustments (d) ($) Compensation Actually Paid ($) 2022 CEO 2,098,436 0 163,143 250,428 182,154 2,185,637 Other NEOs 1,157,780 0 94,788 193,470 150,934 1,210,032 2021 CEO 2,469,929 528,260 223,648 258,096 109,976 2,017,197 Other NEOs 1,280,518 193,093 93,964 198,990 107,362 1,089,491 2020 CEO 3,149,426 1,132,717 258,645 253,766 (174,499 ) 1,847,089 Other NEOs 1,452,162 383,722 109,136 195,565 (75,635 ) 905,376 Year Executives Service Cost ($) Prior Service Cost ($) Total Pension Value Adjustment ($) 2022 CEO 163,143 0 163,143 Other NEOs 94,788 0 94,788 2021 CEO 223,648 0 223,648 Other NEOs 93,694 0 93,694 2020 CEO 258,645 0 258,645 Other NEOs 109,136 0 109,136 The amounts deducted or added in calculating the equity award adjustments are as follows: Year Executive Year end fair value of equity awards granted during the year ($) Year over year change in fair value of outstanding and unvested equity awards ($) Fair value as of vesting date of equity awards granted and vested in the year ($) Year over year change in fair value of equity awards granted in prior years that vested in the year ($) Fair value at the end of the prior year of equity awards that failed to meet vesting conditions in the year ($) Value of dividends or other earnings paid on stock or option awards reflected in fair value or total compensation Total equity award adjustments ($) 2022 CEO 248,266 (96,885) 0 0 0 30,773 182,154 Other NEOs 191,799 (59,261) 0 0 0 18,396 150,934 2021 CEO 224,482 (133,924) 0 0 0 19,418 109,976 Other NEOs 173,074 (76,117) 0 0 0 10,406 107,362 2020 CEO 242,957 (158,814) 0 (258,642) 0 0 (174,499) Other NEOs 188,192 (110,089) 0 (153,738) 0 0 (75,635) | ||
| Non-PEO NEO Average Total Compensation Amount | $ 1,157,780 | 1,280,518 | 1,452,162 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 1,210,032 | 1,089,491 | 905,376 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | SEC rules require certain adjustments be made to the Summary Compensation Table totals to determine compensation “actually paid” as reported in the Pay versus Performance table. The following tables detail these adjustments: Year Executives Summary Compensation Table Total ($) Deduct Reported Change in Actuarial Present Value of Pension Benefits (a) ($) Add Pension Benefit Adjustments (b) ($) Deduct Reported Value of Equity Awards (c) ($) Add Equity Award Adjustments (d) ($) Compensation Actually Paid ($) 2022 CEO 2,098,436 0 163,143 250,428 182,154 2,185,637 Other NEOs 1,157,780 0 94,788 193,470 150,934 1,210,032 2021 CEO 2,469,929 528,260 223,648 258,096 109,976 2,017,197 Other NEOs 1,280,518 193,093 93,964 198,990 107,362 1,089,491 2020 CEO 3,149,426 1,132,717 258,645 253,766 (174,499 ) 1,847,089 Other NEOs 1,452,162 383,722 109,136 195,565 (75,635 ) 905,376 Year Executives Service Cost ($) Prior Service Cost ($) Total Pension Value Adjustment ($) 2022 CEO 163,143 0 163,143 Other NEOs 94,788 0 94,788 2021 CEO 223,648 0 223,648 Other NEOs 93,694 0 93,694 2020 CEO 258,645 0 258,645 Other NEOs 109,136 0 109,136 The amounts deducted or added in calculating the equity award adjustments are as follows: Year Executive Year end fair value of equity awards granted during the year ($) Year over year change in fair value of outstanding and unvested equity awards ($) Fair value as of vesting date of equity awards granted and vested in the year ($) Year over year change in fair value of equity awards granted in prior years that vested in the year ($) Fair value at the end of the prior year of equity awards that failed to meet vesting conditions in the year ($) Value of dividends or other earnings paid on stock or option awards reflected in fair value or total compensation Total equity award adjustments ($) 2022 CEO 248,266 (96,885) 0 0 0 30,773 182,154 Other NEOs 191,799 (59,261) 0 0 0 18,396 150,934 2021 CEO 224,482 (133,924) 0 0 0 19,418 109,976 Other NEOs 173,074 (76,117) 0 0 0 10,406 107,362 2020 CEO 242,957 (158,814) 0 (258,642) 0 0 (174,499) Other NEOs 188,192 (110,089) 0 (153,738) 0 0 (75,635) | ||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | |||
| Compensation Actually Paid vs. Net Income [Text Block] | |||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | |||
| Tabular List [Table Text Block] | Company Financial Performance Measures The items listed below represent the most important metrics we used to determine CAP for fiscal year 2022 as further described in our Compensation Discussion and Analysis beginning on page 14. Most Important Performance Measures Operating Profit Net Income EPS | ||
| Total Shareholder Return Amount | $ 68.64 | 73.56 | 83.52 |
| Peer Group Total Shareholder Return Amount | 110.83 | 148.99 | 117.89 |
| Net Income (Loss) | $ 279,538,000 | $ 190,908,000 | $ 270,568,000 |
| Company Selected Measure Amount | 363,000 | 266,000 | 319,000 |
| PEO Name | Mr. Gottwald | ||
| Operating Profit | $ 363,000,000 | $ 266,000,000 | $ 319,000,000 |
| Bonus Expense | $ 8,000,000 | 8,000,000 | 7,000,000 |
| Measure [Axis]: 1 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Operating Profit | ||
| Non-GAAP Measure Description [Text Block] | (5) The 2022 operating profit of approximately $363 million is based on our 2022 operating profit (calculated in accordance with GAAP) of $355 million, excluding a charge of $8 million for the bonus expense. The 2021 operating profit of approximately $266 million is based on our 2021 operating profit (calculated in accordance with GAAP) of $258 million, excluding a charge of $8 million for the bonus expense. The 2020 operating profit of approximately $319 million is based on our 2020 operating profit (calculated in accordance with GAAP) of $312 million, excluding a charge of $7 million for the bonus expense. | ||
| Measure [Axis]: 2 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Net Income | ||
| Measure [Axis]: 3 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | EPS | ||
| GAAP [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Operating Profit | $ 355,000,000 | 258,000,000 | 312,000,000 |
| PEO [Member] | Change in Actuarial Present Value of Pension Benefits [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 0 | (528,260) | (1,132,717) |
| PEO [Member] | Pension Benefit Adjustments [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 163,143 | 223,648 | 258,645 |
| PEO [Member] | Value of Equity Awards [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (250,428) | (258,096) | (253,766) |
| PEO [Member] | Equity Award Adjustments [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 182,154 | 109,976 | (174,499) |
| PEO [Member] | Pension Adjustments Service Cost [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Pension | 163,143 | 223,648 | 258,645 |
| PEO [Member] | Pension Adjustments Prior Service Cost [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Pension | 0 | 0 | 0 |
| PEO [Member] | Net Adjustments For Pension [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Pension | 163,143 | 223,648 | 258,645 |
| PEO [Member] | Fair Value of Equity Awards Granted [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 248,266 | 224,482 | 242,957 |
| PEO [Member] | Fair Value of Outstanding and Unvested Equity Awards [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | (96,885) | (133,924) | (158,814) |
| PEO [Member] | Fair Value of Equity Awards Granted and Vested [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 0 | 0 | 0 |
| PEO [Member] | Change in Fair Value of Equity Awards Granted [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 0 | 0 | (258,642) |
| PEO [Member] | Fair Value of Equity Awards that Failed to Meet Vesting Conditions [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 0 | 0 | 0 |
| PEO [Member] | Value of Dividends or Other Earnings Paid on Stock or Option Awards [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 30,773 | 19,418 | 0 |
| PEO [Member] | Total Equity Award Adjustments [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 182,154 | 109,976 | (174,499) |
| Non-PEO NEO [Member] | Change in Actuarial Present Value of Pension Benefits [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 0 | (193,093) | (383,722) |
| Non-PEO NEO [Member] | Pension Benefit Adjustments [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 94,788 | 93,964 | 109,136 |
| Non-PEO NEO [Member] | Value of Equity Awards [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (193,470) | (198,990) | (195,565) |
| Non-PEO NEO [Member] | Equity Award Adjustments [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 150,934 | 107,362 | (75,635) |
| Non-PEO NEO [Member] | Pension Adjustments Service Cost [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Pension | 94,788 | 93,694 | 109,136 |
| Non-PEO NEO [Member] | Pension Adjustments Prior Service Cost [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Pension | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Net Adjustments For Pension [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Pension | 94,788 | 93,694 | 109,136 |
| Non-PEO NEO [Member] | Fair Value of Equity Awards Granted [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 191,799 | 173,074 | 188,192 |
| Non-PEO NEO [Member] | Fair Value of Outstanding and Unvested Equity Awards [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | (59,261) | (76,117) | (110,089) |
| Non-PEO NEO [Member] | Fair Value of Equity Awards Granted and Vested [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Change in Fair Value of Equity Awards Granted [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 0 | 0 | (153,738) |
| Non-PEO NEO [Member] | Fair Value of Equity Awards that Failed to Meet Vesting Conditions [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 0 | 0 | 0 |
| Non-PEO NEO [Member] | Value of Dividends or Other Earnings Paid on Stock or Option Awards [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | 18,396 | 10,406 | 0 |
| Non-PEO NEO [Member] | Total Equity Award Adjustments [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Equity Awards | $ 150,934 | $ 107,362 | $ (75,635) |
