| Cover | 12 Months Ended |
| Dec. 31, 2023 | |
| Document Information [Line Items] | |
| Document Type | PRE 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | Koppers Holdings Inc. |
| Entity Central Index Key | 0001315257 |
| Pay vs Performance Disclosure - USD ($) | 12 Months Ended | |||
| Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
| Pay vs Performance Disclosure | ||||
| Pay vs Performance Disclosure, Table | 2023 Pay Versus Performance Disclosure Pay Versus Performance Table As required by applicable SEC rules, we are providing the following information about the relationship between the “compensation actually paid” to certain individuals and certain of our financial performance measures. For further information concerning our pay-for-performance Year Summary (1) Compensation (2) Average Non-PEO (3) Average Non-PEO (4) Value of Initial Fixed Net (6) Adjusted (7) Total (5) Peer Group (5) 2023 $5,960,553 $17,568,133 $1,579,169 $4,141,388 $135.90 $163.68 $ 89.8 $256.4 2022 5,770,002 2,902,239 1,404,909 903,710 74.33 136.42 63.2 228.1 2021 5,196,873 3,801,572 1,362,868 982,151 81.89 145.27 84.9 223.5 2020 4,126,547 2,936,710 1,191,596 971,101 81.53 122.68 121.0 211.5 (1) The amounts shown in this column represent the amount of total compensation reported for Leroy M. Ball, our Chief Executive Officer, who is considered our Principal Executive Officer under applicable SEC rules (the “PEO”), for each corresponding year in the “Total” column of the Summary Compensation Table above. (2) The amounts shown in this column represent the amount of “compensation actually paid” to Mr. Ball, as computed in accordance with Item 402(v) of Regulation S-K. S-K, Year Reported (a) Less Reported (b) Plus Adjusted Value of Equity (c) Compensation Actually Paid 2023 $5,960,553 $ 3,572,221 $15,179,801 $17,568,133 2022 5,770,002 3,745,653 877,890 2,902,239 2021 5,196,873 3,099,995 1,704,694 3,801,572 2020 4,126,547 2,060,259 870,422 2,936,710 (a) This column represents the amount of total compensation reported for Mr. Ball for each corresponding year in the “Total” column of the Summary Compensation Table above. (b) This column represents the grant date fair value of equity awards reported in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table above for the applicable year. (c) This column represents an adjustment to the amounts in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for the applicable year (a “Subject Year”). For a Subject Year, the adjusted amount replaces the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for Mr. Ball to arrive at “compensation actually paid” to Mr. Ball for that Subject Year. The adjusted amount is determined by adding (or subtracting, as applicable) the following for that Subject Year: (i) the year-end EBITDA PSUs granted during 2023 is 200 percent of fair value as this represents the probable performance as of December 31, 2023 for the period 2023-2025. For stock options, the fair value or change in fair value, as applicable, was determined using a Black-Scholes valuation model. The model references the closing stock price, in addition to the stock option’s strike price, expected life, volatility, expected dividend yield and risk-free rate as of the applicable measurement date. The amounts added or subtracted to determine the adjusted amount are as follows: Year Year End Fair Value Year over Year Change in Fair Value Fair Value at the End Adjusted Value of 2023 $9,733,619 $ 5,183,390 $ 262,792 $ — $15,179,801 2022 2,339,493 (949,827 ) (388,914 ) (122,862 ) 877,890 2021 2,825,381 (1,255,454 ) 134,767 — 1,704,694 2020 3,930,775 (1,003,142 ) (1,163,408 ) (893,803 ) 870,422 (3) The amounts shown in this column represent the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Total” column of the Summary Compensation Table in each applicable year. Please refer to the Summary Compensation Table above for the applicable year. The names of each of the NEOs (excluding Mr. Ball) included for purposes of calculating the average amounts in each applicable year are as follows: (i) for 2023 and 2022, Jimmi Sue Smith, James A. Sullivan, Stephanie L. Apostolou and Leslie S. Hyde; (ii) for 2021, Michael J. Zugay, James A. Sullivan, Leslie S. Hyde and Stephanie L. Apostolou; and (iii) for 2020, Michael J. Zugay, James A. Sullivan, Leslie S. Hyde, Stephanie L. Apostolou, Steven R. Lacy and Douglas J. Fenwick. (4) The amounts shown in this column represent the average amount of “compensation actually paid” to the NEOs as a group (excluding Mr. Ball), as computed in accordance with Item 402(v) of Regulation S-K. S-K, Year Average Reported Non-PEO (a) Less Average Reported Non-PEO (b) Less Average Reported Non-PEO (c) Plus Average Non-PEO (d) Average Non-PEO 2023 $1,579,169 $ 684,135 $ 4,818 $3,251,172 $4,141,388 2022 1,404,909 700,122 — 198,923 903,710 2021 1,362,868 635,750 — 255,033 982,151 2020 1,191,596 436,682 6,591 222,778 971,101 (a) This column represents the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Total” column of the Summary Compensation Table above in each applicable year. (b) This column represents the average of the total amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table above in each applicable year. (c) This column represents the average of the change in pension value amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Change in Pension Value and Nonqualified Deferred Compensation Earnings” column in the Summary Compensation Table above in each applicable year. (d) This column represents an adjustment to the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table in each applicable year determined using the same methodology described above in Footnote 2(c). For each year, the adjusted amount replaces the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for each NEO (excluding Mr. Ball) to arrive at “compensation actually paid” to each NEO (excluding Mr. Ball) for that year, which is then averaged to determine the average “compensation actually Year Average Average Average Average Average Adjusted 2023 $2,237,990 $ 971,370 $ — $ 41,812 $ — $3,251,172 2022 439,530 (172,654 ) — (44,192 ) (23,761 ) 198,923 2021 464,793 (242,260 ) 132,024 22,112 (121,636 ) 255,033 2020 698,499 (159,014 ) 148,753 (219,104 ) (246,356 ) 222,778 (5) The amounts shown in these columns represent an initial $100 investment in each of our common stock and the S&P SmallCap 600 Materials for the cumulative periods from December 31, 2019 through the end of the applicable fiscal year (assuming reinvestment of the pre-tax value of dividends paid during the relevant period). (6) The amounts shown in this column represent the amount of net income reflected in our audited financial statements for the applicable year. (7) The amounts shown in this column represent the amount of our adjusted EBITDA as calculated for performance measurement under our annual incentive plan for the applicable year and to measure performance of the EBITDA PSUs over the relevant three-year measurement period. Adjusted EBITDA, as measured under the annual incentive plan and for the EBITDA PSUs, is defined as earnings before interest, taxes, depreciation and amortization, as adjusted by our management development and compensation committee in its discretion to account for certain items, as set forth on Appendix B hereto. | |||
| Company Selected Measure Name | Adjusted EBITDA | |||
| Named Executive Officers, Footnote | (3) The amounts shown in this column represent the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Total” column of the Summary Compensation Table in each applicable year. Please refer to the Summary Compensation Table above for the applicable year. The names of each of the NEOs (excluding Mr. Ball) included for purposes of calculating the average amounts in each applicable year are as follows: (i) for 2023 and 2022, Jimmi Sue Smith, James A. Sullivan, Stephanie L. Apostolou and Leslie S. Hyde; (ii) for 2021, Michael J. Zugay, James A. Sullivan, Leslie S. Hyde and Stephanie L. Apostolou; and (iii) for 2020, Michael J. Zugay, James A. Sullivan, Leslie S. Hyde, Stephanie L. Apostolou, Steven R. Lacy and Douglas J. Fenwick. | |||
| Peer Group Issuers, Footnote | The amounts shown in these columns represent an initial $100 investment in each of our common stock and the S&P SmallCap 600 Materials for the cumulative periods from December 31, 2019 through the end of the applicable fiscal year (assuming reinvestment of the pre-tax value of dividends paid during the relevant period). | |||
| PEO Total Compensation Amount | $ 5,960,553 | $ 5,770,002 | $ 5,196,873 | $ 4,126,547 |
| PEO Actually Paid Compensation Amount | $ 17,568,133 | 2,902,239 | 3,801,572 | 2,936,710 |
| Adjustment To PEO Compensation, Footnote | (2) The amounts shown in this column represent the amount of “compensation actually paid” to Mr. Ball, as computed in accordance with Item 402(v) of Regulation S-K. S-K, Year Reported (a) Less Reported (b) Plus Adjusted Value of Equity (c) Compensation Actually Paid 2023 $5,960,553 $ 3,572,221 $15,179,801 $17,568,133 2022 5,770,002 3,745,653 877,890 2,902,239 2021 5,196,873 3,099,995 1,704,694 3,801,572 2020 4,126,547 2,060,259 870,422 2,936,710 (a) This column represents the amount of total compensation reported for Mr. Ball for each corresponding year in the “Total” column of the Summary Compensation Table above. (b) This column represents the grant date fair value of equity awards reported in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table above for the applicable year. (c) This column represents an adjustment to the amounts in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for the applicable year (a “Subject Year”). For a Subject Year, the adjusted amount replaces the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for Mr. Ball to arrive at “compensation actually paid” to Mr. Ball for that Subject Year. The adjusted amount is determined by adding (or subtracting, as applicable) the following for that Subject Year: (i) the year-end EBITDA PSUs granted during 2023 is 200 percent of fair value as this represents the probable performance as of December 31, 2023 for the period 2023-2025. For stock options, the fair value or change in fair value, as applicable, was determined using a Black-Scholes valuation model. The model references the closing stock price, in addition to the stock option’s strike price, expected life, volatility, expected dividend yield and risk-free rate as of the applicable measurement date. The amounts added or subtracted to determine the adjusted amount are as follows: Year Year End Fair Value Year over Year Change in Fair Value Fair Value at the End Adjusted Value of 2023 $9,733,619 $ 5,183,390 $ 262,792 $ — $15,179,801 2022 2,339,493 (949,827 ) (388,914 ) (122,862 ) 877,890 2021 2,825,381 (1,255,454 ) 134,767 — 1,704,694 2020 3,930,775 (1,003,142 ) (1,163,408 ) (893,803 ) 870,422 | |||
| Non-PEO NEO Average Total Compensation Amount | $ 1,579,169 | 1,404,909 | 1,362,868 | 1,191,596 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 4,141,388 | 903,710 | 982,151 | 971,101 |
| Adjustment to Non-PEO NEO Compensation Footnote | (4) The amounts shown in this column represent the average amount of “compensation actually paid” to the NEOs as a group (excluding Mr. Ball), as computed in accordance with Item 402(v) of Regulation S-K. S-K, Year Average Reported Non-PEO (a) Less Average Reported Non-PEO (b) Less Average Reported Non-PEO (c) Plus Average Non-PEO (d) Average Non-PEO 2023 $1,579,169 $ 684,135 $ 4,818 $3,251,172 $4,141,388 2022 1,404,909 700,122 — 198,923 903,710 2021 1,362,868 635,750 — 255,033 982,151 2020 1,191,596 436,682 6,591 222,778 971,101 (a) This column represents the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Total” column of the Summary Compensation Table above in each applicable year. (b) This column represents the average of the total amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table above in each applicable year. (c) This column represents the average of the change in pension value amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Change in Pension Value and Nonqualified Deferred Compensation Earnings” column in the Summary Compensation Table above in each applicable year. (d) This column represents an adjustment to the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table in each applicable year determined using the same methodology described above in Footnote 2(c). For each year, the adjusted amount replaces the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for each NEO (excluding Mr. Ball) to arrive at “compensation actually paid” to each NEO (excluding Mr. Ball) for that year, which is then averaged to determine the average “compensation actually Year Average Average Average Average Average Adjusted 2023 $2,237,990 $ 971,370 $ — $ 41,812 $ — $3,251,172 2022 439,530 (172,654 ) — (44,192 ) (23,761 ) 198,923 2021 464,793 (242,260 ) 132,024 22,112 (121,636 ) 255,033 2020 698,499 (159,014 ) 148,753 (219,104 ) (246,356 ) 222,778 | |||
| Compensation Actually Paid vs. Total Shareholder Return | Compensation Actually Paid and Company and Peer Group TSR | |||
| Compensation Actually Paid vs. Net Income | Compensation Actually Paid and Net Income | |||
| Compensation Actually Paid vs. Company Selected Measure | Compensation Actually Paid and Adjusted EBITDA | |||
| Total Shareholder Return Vs Peer Group | Compensation Actually Paid and Company and Peer Group TSR | |||
| Tabular List, Table | Financial Performance Measures As described in greater detail in the Compensation Discussion and Analysis section above, our executive compensation program reflects a pay-for-performance Most Important Financial Performance Measures Adjusted EBITDA Total Shareholder Return Operating Cash Flow | |||
| Total Shareholder Return Amount | $ 135.9 | 74.33 | 81.89 | 81.53 |
| Peer Group Total Shareholder Return Amount | 163.68 | 136.42 | 145.27 | 122.68 |
| Net Income (Loss) | $ 89,800,000 | $ 63,200,000 | $ 84,900,000 | $ 121,000,000 |
| Company Selected Measure Amount | 256,400,000 | 228,100,000 | 223,500,000 | 211,500,000 |
| PEO Name | Leroy M. Ball | |||
| Measure:: 1 | ||||
| Pay vs Performance Disclosure | ||||
| Name | Adjusted EBITDA | |||
| Measure:: 2 | ||||
| Pay vs Performance Disclosure | ||||
| Name | Total Shareholder Return | |||
| Measure:: 3 | ||||
| Pay vs Performance Disclosure | ||||
| Name | Operating Cash Flow | |||
| PEO | Reported Summary Compensation Table Value Of Equity Awards [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | $ (3,572,221) | $ (3,745,653) | $ (3,099,995) | $ (2,060,259) |
| PEO | Adjusted Value of Equity Awards [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 15,179,801 | 877,890 | 1,704,694 | 870,422 |
| PEO | Year End Fair Value of Equity Awards Granted in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 9,733,619 | 2,339,493 | 2,825,381 | 3,930,775 |
| PEO | Year over Year Change in Fair Value of Outstanding and Unvested Equity Awards at FYE Granted in Prior Years [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 5,183,390 | (949,827) | (1,255,454) | (1,003,142) |
| PEO | Change in Fair Value of Equity Awards Granted in Prior Years that Vested in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 262,792 | (388,914) | 134,767 | (1,163,408) |
| PEO | Fair Value at the End of the Prior Year of Equity Awards that Failed to Meet Vesting Conditions in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 0 | (122,862) | 0 | (893,803) |
| Non-PEO NEO | Reported Summary Compensation Table Value Of Equity Awards [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | (684,135) | (700,122) | (635,750) | (436,682) |
| Non-PEO NEO | Reported Summary Compensation Table Value of Accumulated Pension Benefit [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | (4,818) | 0 | 0 | (6,591) |
| Non-PEO NEO | Adjusted Value of Equity Awards [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 3,251,172 | 198,923 | 255,033 | 222,778 |
| Non-PEO NEO | Year End Fair Value of Equity Awards Granted in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 2,237,990 | 439,530 | 464,793 | 698,499 |
| Non-PEO NEO | Year over Year Change in Fair Value of Outstanding and Unvested Equity Awards at FYE Granted in Prior Years [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 971,370 | (172,654) | (242,260) | (159,014) |
| Non-PEO NEO | Fair Value as of Vesting Date of Equity Awards Granted in the Year and Vested in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 0 | 0 | 132,024 | 148,753 |
| Non-PEO NEO | Change in Fair Value of Equity Awards Granted in Prior Years that Vested in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | 41,812 | (44,192) | 22,112 | (219,104) |
| Non-PEO NEO | Fair Value at the End of the Prior Year of Equity Awards that Failed to Meet Vesting Conditions in the Year [Member] | ||||
| Pay vs Performance Disclosure | ||||
| Adjustment to Compensation, Amount | $ 0 | $ (23,761) | $ (121,636) | $ (246,356) |
