XML 46 R31.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Debt (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2012
Debt Disclosure [Abstract] |
Principal amount, carrying amount, and interest expense of the notes | The following tables provide additional information regarding the Convertible Notes:
| September 30, 2012 |  | December 31, 2011
Principal amount | $ | 175.0 |  |  | $ | 175.0 |
Less: unamortized issuance discount | (21.6 | ) |  | (27.0 | )
Carrying amount, net of discount | $ | 153.4 |  |  | $ | 148.0 |

X
- Definition Principal amount, carrying amount, and interest expense of the notes. + References No definition available. + Details
Name: | kalu_PrincipalAmountCarryingAmountAndInterestExpenseOfNotesTableTextBlock
Namespace Prefix: | kalu_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration