XML 60 R49.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Summary of Significant Accounting Policies - Summarizes of Total Deferred Implementation Costs and Accumulated Amortization Related to Hosted Cloud Computing Software (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Hosting Arrangement, Service Contract [Abstract] |  |  |
Deferred implementation costs | $ 11.7 | $ 10.4 | $ 7.8
Average Useful Life | 9 years |  |
Accumulated amortization | $ (2.2) | $ (1.1) | $ (0.1)

X
- Definition Hosting arrangement service contract implementation cost average useful life. + References No definition available. + Details
Name: | kalu_HostingArrangementServiceContractImplementationCostAverageUsefulLife
Namespace Prefix: | kalu_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_HostingArrangementServiceContractAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of accumulated amortization of capitalized implementation cost from hosting arrangement that is service contract. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 3 -SubTopic 40 -Topic 350 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482558/350-40-50-3 + Details
Name: | us-gaap_HostingArrangementServiceContractImplementationCostCapitalizedAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before accumulated amortization, of capitalized implementation cost from hosting arrangement that is service contract. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Section 50 -Paragraph 3 -SubTopic 40 -Topic 350 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482558/350-40-50-3 + Details
Name: | us-gaap_HostingArrangementServiceContractImplementationCostCapitalizedBeforeAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant