XML 124 R97.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Retirement Benefits (Details 17) - Pension Benefits [Member] - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Multiemployer Plan Disclosure [Line Items] |  |  |  |
Company Contributions |  | $ 5.6 | $ 5.4 | $ 4.5
Steelworkers Western Independent Shops Pension Plan [Member] |  |  |  |
Multiemployer Plan Disclosure [Line Items] |  |  |  |
Pension Plan Number |  | 001 |  |
Pension Protection Act Zone Status | [1] | Green | Green |
FIP / RP Status Pending / Implemented | [2] | NA |  |
Company Contributions |  | $ 0.9 | $ 0.8 | 0.6
Surcharge Imposed | [3] | No |  |
Expiration Dates of Collective Bargaining Agreements |  | Feb. 29, 2020 |  |
Boilermakers-Blacksmiths National Pension Trust [Member] |  |  |  |
Multiemployer Plan Disclosure [Line Items] |  |  |  |
Pension Plan Number |  | 001 |  |
Pension Protection Act Zone Status | [1] | Red | Yellow |
FIP / RP Status Pending / Implemented | [2] | Implemented |  |
Company Contributions |  | $ 2.5 | $ 2.5 | 2.2
Surcharge Imposed | [3] | No |  |
Expiration Dates of Collective Bargaining Agreements |  | Sep. 30, 2026 |  |
IAM National Pension Fund [Member] |  |  |  |
Multiemployer Plan Disclosure [Line Items] |  |  |  |
Pension Plan Number |  | 002 |  |
Pension Protection Act Zone Status | [1] | Red | Green |
FIP / RP Status Pending / Implemented | [2] | Implemented |  |
Company Contributions |  | $ 2.2 | $ 2.1 | $ 1.7
Surcharge Imposed | [3] | Yes |  |
Expiration Dates of Collective Bargaining Agreements, First Date | [4] | Nov. 14, 2021 |  |
Expiration Dates of Collective-Bargaining Agreements, Last Date | [4] | Jul. 14, 2022 |  |
[1] | The most recent Pension Protection Act Zone Status is based on information provided to ATI and other participating employers by each plan, as certified by the plan’s actuary. A plan in the “red” zone had been determined to be in “critical status”, based on criteria established by the Internal Revenue Code (Code), and is generally less than 65% funded. A plan in the “yellow” zone has been determined to be in “endangered status”, based on criteria established under the Code, and is generally less than 80% funded. A plan in the “green” zone has been determined to be neither in “critical status” nor in “endangered status”, and is generally at least 80% funded. Additionally, a plan may voluntarily place itself into a rehabilitation plan. In April 2019, the Company received notification from the IAM National Pension Fund (IAM Fund) that its’ actuary certified the IAM Fund as “endangered status” for the plan year beginning January 1, 2019, and that the IAM Fund was voluntarily placing itself in “red” zone status and implementing a rehabilitation plan. A 5% contribution surcharge has been imposed as of June 1, 2019 for the rest of 2019, increasing to a 10% surcharge rate beginning January 1, 2020 in addition to the contribution rate specified in the applicable collective bargaining agreements. The contribution surcharge ends when an employer begins contributing under a collective bargaining agreement that includes terms consistent with the rehabilitation plan. In April 2019, the Company received notification from the Boilermakers-Blacksmiths National Pension Trust (Blacksmiths Trust) that it was certified by its actuary as being in “red” zone status for the plan year beginning January 1, 2019. A rehabilitation plan has been adopted for the Blacksmiths Trust, and the Company and the Blacksmiths union agreed to adopt the rehabilitation plan in 2019 prior to a contribution surcharge being imposed.
[2] | The “FIP / RP Status Pending / Implemented” column indicates whether a Funding Improvement Plan, as required under the Code by plans in the “yellow” zone, or a Rehabilitation Plan, as required under the Code to be adopted by plans in the “red” zone, is pending or has been implemented as of the end of the plan year that ended in 2019.
[3] | The “Surcharge Imposed” column indicates whether ATI’s contribution rate for 2019 included an amount in addition to the contribution rate specified in the applicable collective bargaining agreement, as imposed by a plan in “critical status”, in accordance with the requirements of the Code.
[4] | The Company is party to five separate bargaining agreements that require contributions to this plan. Expiration dates of these collective bargaining agreements range between November 14, 2021 and July 14, 2022.

X
- Definition Amount of contributions made to multiemployer plan by employer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Three digit plan number for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlanNumber
Namespace Prefix: | us-gaap_
Data Type: | us-types:threeDigitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indicate the multiemployer plan's certified zone status as currently required by the Pension Protection Act of 2006 or a subsequent amendment thereof. The zone status categories are red (critical status), orange (seriously endangered), yellow (endangered), and green (none of the above). The acceptable values are "red", "orange", "yellow", "green", "other", and "NA". A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansCertifiedZoneStatus
Namespace Prefix: | us-gaap_
Data Type: | us-types:zoneStatusItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansCollectiveBargainingArrangementExpirationDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan that will expire first in a group of associated collective bargaining arrangements, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansCollectiveBargainingArrangementExpirationDateFirst
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan that will expire last in a group of associated collective bargaining arrangements, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansCollectiveBargainingArrangementExpirationDateLast
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indicate whether a funding improvement plan or rehabilitation plan has been implemented or is pending for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "pending", "implemented", "other", and "NA". + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (f)(1) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansFundingImprovementPlanAndRehabilitationPlan
Namespace Prefix: | us-gaap_
Data Type: | us-types:fundingImprovementAndRehabilitationPlanItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_MultiemployerPlansLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indicate whether the employer paid a surcharge to the pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "yes", and "NA". + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansSurcharge
Namespace Prefix: | us-gaap_
Data Type: | us-types:surchargeItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MultiemployerPlanNameAxis=ati_Multiemployerplan1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MultiemployerPlanNameAxis=ati_Multiemployerplan2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MultiemployerPlanNameAxis=ati_Multiemployerplan3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |