XML 106 R2.htm IDEA: XBRL DOCUMENT
v3.24.1

Pay vs Performance Disclosure - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Pay vs Performance Disclosure |  |  |  |
Pay vs Performance Disclosure, Table | PAY VERSUS PERFORMANCE In accordance with rules adopted by the SEC pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, and Item 402(v) of Regulation S-K, we provide the following disclosure regarding executive compensation and Company performance for the years listed below. For further information concerning ATI’s variable pay-for-performance philosophy and how ATI aligns executive compensation with its performance, see “Executive Compensation — Compensation Discussion and Analysis.” Our Compensation and Leadership Development Committee did not consider the pay versus performance disclosure below in making its pay decisions for any of the years shown.
Year |  | Summary Compensation Table total for CEO ($) (1) |  |  | Compensation actually paid to CEO ($) (2) |  |  | Average Summary Compensation Table total for non-CEO NEOs ($) (3) |  |  | Average Compensation actually paid to non-CEO NEOs ($) (4) |  |  | Value of initial fixed $100 investment based on: |  |  | Net Income ($) |  |  | ATI Adjusted EBITDA ($) (7) |
| Total share- holder return ($) |  |  | Peer group total share-holder return ($) (5) |
2023 |  |  | 7,670,554 |  |  |  | 35,206,270 |  |  |  | 2,902,853 |  |  |  | 12,593,071 |  |  |  | 220.09 |  |  |  | 174.04 |  |  |  | 410,800,000 |  |  |  | 634,600,000 |
2022 |  |  | 11,007,608 |  |  |  | 32,090,373 |  |  |  | 4,410,737 |  |  |  | 11,733,557 |  |  |  | 144.53 |  |  |  | 132.42 |  |  |  | 323,500,000 |  |  |  | 612,800,000 |
2021 |  |  | 7,590,345 |  |  |  | 6,677,580 |  |  |  | 2,792,700 |  |  |  | 2,480,715 |  |  |  | 77,11 |  |  |  | 149.62 |  |  |  | 184,600,000 |  |  |  | 366,500,000 |
2020 |  |  | 5,710,651 |  |  |  | 1,229,666 |  |  |  | 2,107,531 |  |  |  | 692,423 |  |  |  | 81.17 |  |  |  | 116.49 |  |  |  | (1,559,600,000 | ) |  |  | 196,300,000 |
(1) | Reflects total compensation for our CEO, Robert S. Wetherbee, who is our “Principal Executive Officer,” as determined in accordance with Item 402(c) of Regulation S-K and (“Item 402(c)”) and reflected on the Company’s 2023 Summary Compensation Table as shown on page 65 of this Proxy Statement (the “Summary Compensation Table”) for 2023, 2022, 2021 and 2020 as indicated.
(2) | For a reconciliation of Compensation Actually Paid to Total Compensation as reflected on the Summary Compensation Table for Mr Wetherbee, see the immediately following table under the headings “Compensation Actually Paid to CEO.”
(3) | Reflects the average total compensation for our non-CEO NEOs as determined in accordance with Item 402(c) and reflected in the Summary Compensation Table for 2023, 2022, 2021 and 2020 as indicated. Compensation paid to the following executive officers is included in the average amounts shown for each such year:
| 2023: Kimberly A. Fields, Donald P. Newman, Elliot S. Davis and Timothy J. Harris
| 2022: Ms. Fields, Messrs. Newman and Davis and Kevin B. Kramer, who ceased to serve as an executive officer of the Company in 2022 and retired in January 2024.
| 2021: Ms. Fields and Messrs. Newman, Kramer and Davis
| 2020: Ms. Fields and Messrs. Newman and Kramer, as well as John D. Sims, former Executive Vice President for the Company’s HPMC business who retired in mid-2021 and Patrick J. DeCourcy, former Senior Vice President, Finance and Chief Financial Officer, who retired in January 2020.
(4) | For a reconciliation of average Compensation Actually Paid to average Total Compensation as reflected on the Summary Compensation Table for our non-CEO NEOs, see the table below under the heading “Compensation Actually Paid to Non-CEO NEOs.”
(5) | The peer group used for the purposes of this table is the S&P MidCap 400 Industrials Index.
(6) | The Company Selected Measure for purposes of this table is ATI Adjusted EBITDA.
“Compensation Actually Paid,” as determined under applicable SEC rules, reflects adjusted values for unvested and vested equity awards during the years shown in the table based on year-end stock prices, various accounting valuation assumptions, and other adjustments. As a result, Compensation Actually Paid fluctuates, potentially significantly, based on changes in our stock price and other assumed values and does not reflect the actual value realized by our CEO or any of our NEOs in connection with the vesting of those awards. The following table sets forth the adjustments made during each year represented in the Pay Versus Performance Table to arrive at compensation “actually paid” to our CEO during each of the years in question: Compensation Actually Paid to CEO
Year |  | Amounts Reflected in Summary Compensation Table ($) |  |  | YE Fair Value of Equity Compensation granted in Current Year ($) (4) |  |  | Change in CY Fair Value of Unvested Prior Year Equity Awards ($) (5) |  |  | Change in CY Fair Value of Equity Awards Vesting in CY ($) (5) |  |  | Compensation Actually Paid ($) |
| Total Compensation (1) |  |  | Pension Value (2) |  |  | Equity Value (3) |
2023 |  |  | 7,670,554 |  |  |  | (17,259 | ) |  |  | (4,774,796) |  |  |  | 8,913,063 |  |  |  | 13,040,130 |  |  |  | 10,374,578 |  |  |  | 35,206,270 |
2022 |  |  | 11,007,608 |  |  |  | — |  |  |  | (7,555,702) |  |  |  | 18,204,232 |  |  |  | 8,330,568 |  |  |  | 2,103,668 |  |  |  | 32,090,373 |
2021 |  |  | 7,590,345 |  |  |  | — |  |  |  | (4,428,259) |  |  |  | 3,040,422 |  |  |  | (43,181) |  |  |  | 518,253 |  |  |  | 6,677,580 |
2020 |  |  | 5,710,651 |  |  |  | (45,679) |  |  |  | (4,128,163) |  |  |  | 1,035,179 |  |  |  | (1,234,013) |  |  |  | (108,309) |  |  |  | 1,229,666 |
(1) | As determined in accordance with Item 402(c) and reflected on the Summary Compensation Table.
(2) | Amount shown for 2020 reflects the actuarial change in the present value of Mr. Wetherbee’s benefits under all defined benefit pension plans established by the Company, determined using interest rate and mortality rate assumptions consistent with those used in the Company’s financial statements. Effective December 31, 2014, the Company froze future benefit accruals in the ATI Pension Plan for all participating employees other than those in contractual employment arrangements. Also effective December 31, 2014, the Company froze the defined benefit-type non-qualified deferred compensation plans in which salaried employees participate, including the defined benefit portion of the ATI Benefit Restoration Plan in which Mr. Wetherbee participates. In 2020, the discount rate used was 2.6% and had the effect of increasing the pension benefit to Mr. Wetherbee.
(3) | Aggregate grant date fair value, determined in accordance with FASB ASC Topic 718, of awards made to Mr. Wetherbee under the Company’s LTIP in 2023, 2022, 2021 and 2020 as indicated. Grant date fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the applicable grant date. Grant date fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(4) | Aggregate year-end 2023, 2022, 2021 and 2020 (as applicable) fair value of the awards described in footnote (3) above. Year-end fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the last trading day of the applicable year. Year-end fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(5) | Changes in fair value determined by comparing fair values determined in the manner described above with comparable prior year values.
The following table sets forth the adjustments made during each year represented in the Pay Versus Performance Table to arrive at compensation “actually paid” to our non-CEO NEOs during each of the years in question: Compensation Actually Paid to Non-CEO NEOs
Year |  | Amounts Reflected in Summary Compensation Table ($) |  |  | YE Fair Value of Equity Compensation granted in Current Year ($) (4) |  |  | Change in CY Fair Value of Unvested Prior Year Equity Awards ($) (5) |  |  | Change in CY Fair Value of Equity Awards Vesting in CY ($) (5) |  |  | Prior Year-End Fair Value of Equity Awards Forfeited in CY ($) (6) |  |  | Compensation Actually Paid ($) |
| Total Compensation (1) |  |  | Pension Value (2) |  |  | Equity Value (3) |
2023 |  |  | 2,902,853 |  |  |  | — |  |  |  | (1,549,120 | ) |  |  | 2,776,371 |  |  |  | 5,712,179 |  |  |  | 2,750,786 |  |  |  | — |  |  |  | 12,593,071 |
2022 |  |  | 4,410,737 |  |  |  | — |  |  |  | (2,766,323 | ) |  |  | 6,781,978 |  |  |  | 2,710,245 |  |  |  | 596,920 |  |  |  | — |  |  |  | 11,733,557 |
2021 |  |  | 2,792,700 |  |  |  | — |  |  |  | (1,392,976 | ) |  |  | 1,003,087 |  |  |  | (12,807 | ) |  |  | 90,710 |  |  |  | — |  |  |  | 2,480,715 |
2020 |  |  | 2,107,531 |  |  |  | (161,741 | ) |  |  | (1,108,151 | ) |  |  | 393,196 |  |  |  | (387,167 | ) |  |  | (86,442 | ) |  |  | (64,803 | ) |  |  | 692,423 |
(1) | As determined in accordance with Item 402(c) and reflected on the Summary Compensation Table
(2) | Amount shown for 2020 reflects the actuarial change in the present value of benefits for Mr. Sims, who retired in 2021, under all defined benefit pension plans established by the Company, determined using interest rate and mortality rate assumptions consistent with those used in the Company’s financial statements. Effective December 31, 2014, the Company froze future benefit accruals in the ATI Pension Plan for all participating employees other than those in contractual employment arrangements. Also effective December 31, 2014, the Company froze the defined benefit-type non-qualified deferred compensation plans in which salaried employees participate, including the defined benefit portion of the ATI Benefit Restoration Plan in which Mr. Sims participated. In 2020, the discount rate used was 2.6% and had the effect of increasing the pension benefit to Mr. Sims.
(3) | Average grant date fair value, determined in accordance with FASB ASC Topic 718, of awards made to NEOs under the Company’s LTIP in 2022, 2021 and 2020 as indicated. Grant date fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the applicable grant date. Grant date fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(4) | Average year-end 2023, 2022, 2021 and 2020 (as applicable) fair value of the awards described in footnote (3) above. Year-end fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the last trading day of the applicable year. Year-end fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(5) | Changes in fair value determined by comparing fair values determined in the manner described above with comparable prior year values.
(6) | Includes amounts forfeited by Mr. DeCourcy in connection with his retirement.
Company Selected Measure Name | ATI Adjusted EBITDA |  |  |
Named Executive Officers, Footnote |
(3) | Reflects the average total compensation for our non-CEO NEOs as determined in accordance with Item 402(c) and reflected in the Summary Compensation Table for 2023, 2022, 2021 and 2020 as indicated. Compensation paid to the following executive officers is included in the average amounts shown for each such year:
| 2023: Kimberly A. Fields, Donald P. Newman, Elliot S. Davis and Timothy J. Harris
| 2022: Ms. Fields, Messrs. Newman and Davis and Kevin B. Kramer, who ceased to serve as an executive officer of the Company in 2022 and retired in January 2024.
| 2021: Ms. Fields and Messrs. Newman, Kramer and Davis
| 2020: Ms. Fields and Messrs. Newman and Kramer, as well as John D. Sims, former Executive Vice President for the Company’s HPMC business who retired in mid-2021 and Patrick J. DeCourcy, former Senior Vice President, Finance and Chief Financial Officer, who retired in January 2020.
Peer Group Issuers, Footnote | The peer group used for the purposes of this table is the S&P MidCap 400 Industrials Index. |  |  |
PEO Total Compensation Amount | $ 7,670,554 | $ 11,007,608 | $ 7,590,345 | $ 5,710,651
PEO Actually Paid Compensation Amount | $ 35,206,270 | 32,090,373 | 6,677,580 | 1,229,666
Adjustment To PEO Compensation, Footnote | Compensation Actually Paid to CEO
Year |  | Amounts Reflected in Summary Compensation Table ($) |  |  | YE Fair Value of Equity Compensation granted in Current Year ($) (4) |  |  | Change in CY Fair Value of Unvested Prior Year Equity Awards ($) (5) |  |  | Change in CY Fair Value of Equity Awards Vesting in CY ($) (5) |  |  | Compensation Actually Paid ($) |
| Total Compensation (1) |  |  | Pension Value (2) |  |  | Equity Value (3) |
2023 |  |  | 7,670,554 |  |  |  | (17,259 | ) |  |  | (4,774,796) |  |  |  | 8,913,063 |  |  |  | 13,040,130 |  |  |  | 10,374,578 |  |  |  | 35,206,270 |
2022 |  |  | 11,007,608 |  |  |  | — |  |  |  | (7,555,702) |  |  |  | 18,204,232 |  |  |  | 8,330,568 |  |  |  | 2,103,668 |  |  |  | 32,090,373 |
2021 |  |  | 7,590,345 |  |  |  | — |  |  |  | (4,428,259) |  |  |  | 3,040,422 |  |  |  | (43,181) |  |  |  | 518,253 |  |  |  | 6,677,580 |
2020 |  |  | 5,710,651 |  |  |  | (45,679) |  |  |  | (4,128,163) |  |  |  | 1,035,179 |  |  |  | (1,234,013) |  |  |  | (108,309) |  |  |  | 1,229,666 |
(1) | As determined in accordance with Item 402(c) and reflected on the Summary Compensation Table.
(2) | Amount shown for 2020 reflects the actuarial change in the present value of Mr. Wetherbee’s benefits under all defined benefit pension plans established by the Company, determined using interest rate and mortality rate assumptions consistent with those used in the Company’s financial statements. Effective December 31, 2014, the Company froze future benefit accruals in the ATI Pension Plan for all participating employees other than those in contractual employment arrangements. Also effective December 31, 2014, the Company froze the defined benefit-type non-qualified deferred compensation plans in which salaried employees participate, including the defined benefit portion of the ATI Benefit Restoration Plan in which Mr. Wetherbee participates. In 2020, the discount rate used was 2.6% and had the effect of increasing the pension benefit to Mr. Wetherbee.
(3) | Aggregate grant date fair value, determined in accordance with FASB ASC Topic 718, of awards made to Mr. Wetherbee under the Company’s LTIP in 2023, 2022, 2021 and 2020 as indicated. Grant date fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the applicable grant date. Grant date fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(4) | Aggregate year-end 2023, 2022, 2021 and 2020 (as applicable) fair value of the awards described in footnote (3) above. Year-end fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the last trading day of the applicable year. Year-end fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(5) | Changes in fair value determined by comparing fair values determined in the manner described above with comparable prior year values.
Non-PEO NEO Average Total Compensation Amount | $ 2,902,853 | 4,410,737 | 2,792,700 | 2,107,531
Non-PEO NEO Average Compensation Actually Paid Amount | $ 12,593,071 | 11,733,557 | 2,480,715 | 692,423
Adjustment to Non-PEO NEO Compensation Footnote | Compensation Actually Paid to Non-CEO NEOs
Year |  | Amounts Reflected in Summary Compensation Table ($) |  |  | YE Fair Value of Equity Compensation granted in Current Year ($) (4) |  |  | Change in CY Fair Value of Unvested Prior Year Equity Awards ($) (5) |  |  | Change in CY Fair Value of Equity Awards Vesting in CY ($) (5) |  |  | Prior Year-End Fair Value of Equity Awards Forfeited in CY ($) (6) |  |  | Compensation Actually Paid ($) |
| Total Compensation (1) |  |  | Pension Value (2) |  |  | Equity Value (3) |
2023 |  |  | 2,902,853 |  |  |  | — |  |  |  | (1,549,120 | ) |  |  | 2,776,371 |  |  |  | 5,712,179 |  |  |  | 2,750,786 |  |  |  | — |  |  |  | 12,593,071 |
2022 |  |  | 4,410,737 |  |  |  | — |  |  |  | (2,766,323 | ) |  |  | 6,781,978 |  |  |  | 2,710,245 |  |  |  | 596,920 |  |  |  | — |  |  |  | 11,733,557 |
2021 |  |  | 2,792,700 |  |  |  | — |  |  |  | (1,392,976 | ) |  |  | 1,003,087 |  |  |  | (12,807 | ) |  |  | 90,710 |  |  |  | — |  |  |  | 2,480,715 |
2020 |  |  | 2,107,531 |  |  |  | (161,741 | ) |  |  | (1,108,151 | ) |  |  | 393,196 |  |  |  | (387,167 | ) |  |  | (86,442 | ) |  |  | (64,803 | ) |  |  | 692,423 |
(1) | As determined in accordance with Item 402(c) and reflected on the Summary Compensation Table
(2) | Amount shown for 2020 reflects the actuarial change in the present value of benefits for Mr. Sims, who retired in 2021, under all defined benefit pension plans established by the Company, determined using interest rate and mortality rate assumptions consistent with those used in the Company’s financial statements. Effective December 31, 2014, the Company froze future benefit accruals in the ATI Pension Plan for all participating employees other than those in contractual employment arrangements. Also effective December 31, 2014, the Company froze the defined benefit-type non-qualified deferred compensation plans in which salaried employees participate, including the defined benefit portion of the ATI Benefit Restoration Plan in which Mr. Sims participated. In 2020, the discount rate used was 2.6% and had the effect of increasing the pension benefit to Mr. Sims.
(3) | Average grant date fair value, determined in accordance with FASB ASC Topic 718, of awards made to NEOs under the Company’s LTIP in 2022, 2021 and 2020 as indicated. Grant date fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the applicable grant date. Grant date fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(4) | Average year-end 2023, 2022, 2021 and 2020 (as applicable) fair value of the awards described in footnote (3) above. Year-end fair values for RSUs granted in each such year are based on the average of the high and low trading prices for a share of ATI stock on the last trading day of the applicable year. Year-end fair values for PSUs granted in each such year, including BPUs, were estimated using Monte Carlo simulations of stock price correlation, projected dividend yields and other variables over three-year time horizons matching the applicable PSU performance measurement periods.
(5) | Changes in fair value determined by comparing fair values determined in the manner described above with comparable prior year values.
(6) | Includes amounts forfeited by Mr. DeCourcy in connection with his retirement.
Compensation Actually Paid vs. Total Shareholder Return |  |  |  |
Compensation Actually Paid vs. Net Income |  |  |  |
Compensation Actually Paid vs. Company Selected Measure |  |  |  |
Total Shareholder Return Vs Peer Group |  |  |  |
Tabular List, Table | For 2023, the performance measures listed below were identified as the most important to ATI’s compensation-setting process for named executive officers. The importance of EBITDA and cash flow is reflected in our use of these measures when setting performance standards applicable to annual short-term incentive program, while the importance of both relative and absolute TSR are reflected in the performance criteria established for our longer-term, performance vested equity awards.
Performance Measures: |  | Other Factors We Consider:
Net Income Adjusted EBITDA Operating Cash Flow Free Cash Flow Relative Total Shareholder Return Absolute Total Shareholder Return |  | As discussed in greater detail in the “Compensation Discussion and Analysis” portion of this Proxy Statement, in addition to the performance measures listed here, our Compensation and Leadership Development Committee considers a range of factors in determining compensation, including among others: compensation levels among our benchmarking peer group; shareholder feedback; the advice of our independent compensation consultants and other advisors; our effectiveness in attracting and retaining the talent necessary to pursue our strategic goals; and the Committee’s overall evaluation of the individual performance of our CEO and each NEO, both in general and relative to their individual strategic goals for the year.
Reconciliations of Adjusted EBITDA to Net Income (Loss) Attributable to ATI (the most directly comparable GAAP measure) are provided (a) for 2023 on page 37 of our Annual Report on Form 10-K for the year ended December 31, 2023, which we filed with the SEC on February 23, 2024, (b) for 2022 and 2021, on page 32 of our Annual Report on Form 10-K for the year ended December 31, 2022, which we filed with the SEC on February 24, 2023 and (b) for 2020, on page 37 of our Annual Report on Form 10-K for the year ended December 31, 2020, which we filed with the SEC on February 26, 2021. |  |  |
Total Shareholder Return Amount | $ 220.09 | 144.53 | 7,711 | 81.17
Peer Group Total Shareholder Return Amount | 174.04 | 132.42 | 149.62 | 116.49
Net Income (Loss) | $ 410,800,000 | $ 323,500,000 | $ 184,600,000 | $ (1,559,600,000)
Company Selected Measure Amount | 634,600,000 | 612,800,000 | 366,500,000 | 196,300,000
PEO Name | Robert S. Wetherbee |  |  |
Measure:: 1 |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Name | Net Income |  |  |
Measure:: 2 |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Name | Adjusted EBITDA |  |  |
Measure:: 3 |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Name | Operating Cash Flow |  |  |
Measure:: 4 |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Name | Free Cash Flow |  |  |
Measure:: 5 |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Name | Relative Total Shareholder Return |  |  |
Measure:: 6 |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Name | Absolute Total Shareholder Return |  |  |
PEO | Pension Value [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | $ (17,259) |  |  | $ (45,679)
PEO | Equity Value [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | (4,774,796) | $ (7,555,702) | $ (4,428,259) | (4,128,163)
PEO | Fair Value Of Equity Compensation Granted [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | 8,913,063 | 18,204,232 | 3,040,422 | 1,035,179
PEO | Change in Fair Value of Unvested Awards [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | 13,040,130 | 8,330,568 | (43,181) | (1,234,013)
PEO | Change in Fair Value of Vested Awards [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | 10,374,578 | 2,103,668 | 518,253 | (108,309)
Non-PEO NEO | Pension Value [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount |  |  |  | (161,741)
Non-PEO NEO | Equity Value [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | (1,549,120) | (2,766,323) | (1,392,976) | (1,108,151)
Non-PEO NEO | Fair Value Of Equity Compensation Granted [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | 2,776,371 | 6,781,978 | 1,003,087 | 393,196
Non-PEO NEO | Change in Fair Value of Unvested Awards [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | 5,712,179 | 2,710,245 | (12,807) | (387,167)
Non-PEO NEO | Change in Fair Value of Vested Awards [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount | $ 2,750,786 | $ 596,920 | $ 90,710 | (86,442)
Non-PEO NEO | Fail Value of Equity Awards Forfeited [Member] |  |  |  |
Pay vs Performance Disclosure |  |  |  |
Adjustment to Compensation, Amount |  |  |  | $ (64,803)

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToNonPeoNeoCompFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToPeoCompFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_CoSelectedMeasureAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_CoSelectedMeasureName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph iii + Details
Name: | ecd_CompActuallyPaidVsCoSelectedMeasureTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph ii + Details
Name: | ecd_CompActuallyPaidVsNetIncomeTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph i + Details
Name: | ecd_CompActuallyPaidVsTotalShareholderRtnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_MeasureName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_NamedExecutiveOfficersFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iii + Details
Name: | ecd_NonPeoNeoAvgCompActuallyPaidAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph ii + Details
Name: | ecd_NonPeoNeoAvgTotalCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_PeerGroupIssuersFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_PeerGroupTotalShareholderRtnAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iii + Details
Name: | ecd_PeoActuallyPaidCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_PeoName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph ii + Details
Name: | ecd_PeoTotalCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 1 + Details
Name: | ecd_PvpTable
Namespace Prefix: | ecd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 1 + Details
Name: | ecd_PvpTableTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 6 + Details
Name: | ecd_TabularListTableTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_TotalShareholderRtnAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph iv + Details
Name: | ecd_TotalShareholderRtnVsPeerGroupTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-28 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482765/220-10-50-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480175/815-40-65-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-8 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-9 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-11 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-11 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-4 Reference 13: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-10 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section 45 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483581/946-220-45-7 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(9)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(1)(d)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-30 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 60B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B Reference 32: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-31 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 34: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-7 Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 36: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A Reference 37: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ecd_MeasureAxis=1
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=2
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=3
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=4
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=5
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=6
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_ExecutiveCategoryAxis=ecd_PeoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=ati_PensionValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=ati_EquityValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=ati_FairValueOfEquityCompensationGrantedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=ati_ChangeInFairValueOfUnvestedAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=ati_ChangeInFairValueOfVestedAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_ExecutiveCategoryAxis=ecd_NonPeoNeoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=ati_FailValueOfEquityAwardsForfeitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |