XML 24 R113.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Business Segments (Details2) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Segment Reporting Other Significant Reconciling Item [Line Items] |  |  |
Depreciation and amortization | $ 151.1 | $ 156.4 | $ 160.8
Capital expenditures | 168.2 | 139.2 | 122.7
Operating Segments |  |  |
Segment Reporting Other Significant Reconciling Item [Line Items] |  |  |
Depreciation and amortization | 151.1 | 156.4 | 160.8
Capital expenditures | 168.2 | 139.2 | 122.7
Operating Segments | High Performance Materials & Components |  |  |
Segment Reporting Other Significant Reconciling Item [Line Items] |  |  |
Depreciation and amortization | 99.1 | 106.5 | 109.3
Capital expenditures | 132.5 | 79.8 | 62.7
Operating Segments | Flat Rolled Products |  |  |
Segment Reporting Other Significant Reconciling Item [Line Items] |  |  |
Depreciation and amortization | 49.1 | 47.0 | 45.6
Capital expenditures | 34.8 | 56.4 | 59.1
Operating Segments | Corporate [Member] |  |  |
Segment Reporting Other Significant Reconciling Item [Line Items] |  |  |
Depreciation and amortization | 2.9 | 2.9 | 5.9
Capital expenditures | $ 0.9 | $ 3.0 | $ 0.9

X
- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
Name: | us-gaap_DepreciationDepletionAndAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireProductiveAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_SegmentReportingOtherSignificantReconcilingItemLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ati_HighPerformanceMaterialsComponentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ati_FlatRolledProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |