XML 45 R35.htm IDEA: XBRL DOCUMENT
v3.23.3

Basis of Presentation - Additional Information (Details) $ in Millions | 3 Months Ended
--- | ---
Jun. 30, 2022 USD ($)
Significant Accounting Policies [Line Items] |
Impairment of intangible assets | $ 3.1

X
- Definition Significant accounting policies [Line Items] + References No definition available. + Details
Name: | kalu_SignificantAccountingPoliciesLineItems
Namespace Prefix: | kalu_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482665/350-30-50-3 + Details
Name: | us-gaap_ImpairmentOfIntangibleAssetsFinitelived
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration