XML 51 R40.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Restructuring (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2023
2022 Plan |
Restructuring Cost and Reserve [Line Items] |
Summary of Activity Relating to Restructuring Plan Liabilities | The following table summarizes activity relating to the 2022 Restructuring Plan liabilities (in millions of dollars):
BALANCE, December 31, 2021 |  | $ | — |
Restructuring costs |  |  | 2.2 |
Costs paid or otherwise settled 1 |  |  | (0.5 | )
BALANCE, December 31, 2022 |  |  | 1.7 |
Restructuring costs |  |  | 5.0 |
Costs paid or otherwise settled 1 |  |  | (5.5 | )
BALANCE, December 31, 2023 |  | $ | 1.2 |
1. Cash paid during the years ended December 31, 2023 and December 31, 2022 was $5.0 million and $0.4 million, respectively.
2020 Plan |
Restructuring Cost and Reserve [Line Items] |
Summary of Activity Relating to Restructuring Plan Liabilities | The following table summarizes activity relating to the 2020 Restructuring Plan liabilities (in millions of dollars):
BALANCE, December 31, 2020 |  | $ | 1.4 |
Restructuring costs |  |  | — |
Costs paid or otherwise settled |  |  | (0.6 | )
Other adjustments 1 |  |  | (0.8 | )
BALANCE, December 31, 2021 |  | $ | — |
1. In 2021, we revised our production forecasts, thereby reducing the estimated number of headcount reductions necessary under the 2020 Restructuring Plan as compared with our initial requirements. These reductions to accommodate the revised headcount requirements are included in Other adjustments with an offset to Restructuring costs in our Statements of Consolidated Income (Loss).

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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482017/420-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482017/420-10-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482017/420-10-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479823/420-10-S99-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479823/420-10-S99-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(d)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479823/420-10-S99-2 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482017/420-10-50-1 + Details
Name: | us-gaap_RestructuringCostAndReserveLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of costs incurred for restructuring including, but not limited to, exit and disposal activities, remediation, implementation, integration, asset impairment, and charges against earnings from the write-down of assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 5.P.3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479823/420-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482017/420-10-50-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 5.P.4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479823/420-10-S99-2 + Details
Name: | us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RestructuringPlanAxis=kalu_TwoThousandAndTwentyTwoRestructuringPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=kalu_TwoThousandAndTwentyRestructuringPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |