XML 99 R83.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Supplemental Financial Statement Information - Accrued Liabilities (Details) - USD ($) $ in Millions | Dec. 29, 2024 | Dec. 31, 2023
--- | --- | ---
Additional Financial Information Disclosure [Abstract] |  |
Accrued salaries, wages and payroll liabilities | $ 113.6 | $ 102.3
Accrued interest | $ 23.9 | $ 23.7

X
- Definition Disclosures of supplemental information, including descriptions and amounts, related to the balance sheet, income statement, and/or cash flow statement + References No definition available. + Details
Name: | ati_AdditionalFinancialInformationDisclosureAbstract
Namespace Prefix: | ati_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(20)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_EmployeeRelatedLiabilitiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(20)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_InterestPayableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant