XML 48 R19.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Accumulated Other Comprehensive Loss (AOCL) | 12 Months Ended
--- | ---
Dec. 31, 2023
Additional financial information disclosures [Abstract] |
Accumulated Other Comprehensive Loss (AOCL) | Accumulated Other Comprehensive Loss ("AOCL")
Components of AOCL | 2023 |  | 2022
Defined benefit plan liabilities | $ | (101.8) |  |  | $ | (98.0) |
Unrealized gain on financial instruments | 1.6 |  |  | 1.7 |
Other comprehensive loss before income tax effect | (100.2) |  |  | (96.3) |
Income tax effect(1) | 2.3 |  |  | 2.3 |
Accumulated other comprehensive loss | $ | (97.9) |  |  | $ | (94.0) |
(1)The allocation of the income tax effect to the components of other comprehensive loss is as follows:
| 2023 |  | 2022
Defined benefit plan liabilities | $ | 2.6 |  |  | $ | 2.6 |
Unrealized loss on financial instruments | (0.3) |  |  | (0.3) |
The following table summarizes the changes in the accumulated balances for each component of AOCL:
| Defined benefit plan and other postretirement liabilities |  | Unrealized gain (loss) on financial instruments |  | Total, net of tax
Balance, December 31, 2020 | $ | (120.6) |  |  | $ | 1.8 |  |  | $ | (118.8) |
Other comprehensive income (loss) before reclassifications | 31.6 |  |  | — |  |  | 31.6 |
Net amount reclassified to net income (loss) | 5.0 |  |  | (0.1) |  |  | 4.9 |
Balance, December 31, 2021 | (84.0) |  |  | 1.7 |  |  | (82.3) |
Other comprehensive income (loss) before reclassifications | (5.9) |  |  | — |  |  | (5.9) |
Net amount reclassified to net income (loss) | (5.7) |  |  | (0.1) |  |  | (5.8) |
Balance, December 31, 2022 | (95.6) |  |  | 1.6 |  |  | (94.0) |
Other comprehensive income (loss) before reclassifications | (10.1) |  |  | — |  |  | (10.1) |
Net amount reclassified to net income (loss) | 6.3 |  |  | (0.1) |  |  | 6.2 |
Balance, December 31, 2023 | $ | (99.4) |  |  | $ | 1.5 |  |  | $ | (97.9) |
Reclassifications out of AOCL were included in the consolidated statements of operations as follows:
|  |  |  | Year Ended December 31,
AOCL Components |  | Location |  | 2023 |  | 2022 |  | 2021
Defined benefit plan and other postretirement liabilities |  | Cost of goods sold |  | $ | (1.0) |  |  | $ | 3.5 |  |  | $ | 26.8 |
|  | Other income, net |  | — |  |  | (8.9) |  |  | — |
|  | Selling, general and administrative expenses |  | (0.2) |  |  | 3.3 |  |  | 2.9 |
|  | Other operating expense (income), net |  | (2.6) |  |  | (9.0) |  |  | 7.3 |
|  | Income tax expense |  | — |  |  | (0.3) |  |  | (0.4) |
|  | Net of tax |  | $ | (3.8) |  |  | $ | (11.4) |  |  | $ | 36.6 |
Gain (loss) on financial instruments |  | Cost of goods sold |  | $ | (0.1) |  |  | $ | (0.2) |  |  | $ | (0.1) |
|  | Income tax effect |  | $ | — |  |  | (0.1) |  |  | 0.0 |
|  | Net of tax |  | $ | (0.1) |  |  | $ | (0.3) |  |  | $ | (0.1) |

X
- Definition Additional financial information disclosures + References No definition available. + Details
Name: | cenx_AdditionalfinancialinformationdisclosuresAbstract
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(21)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(23)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org//220/tableOfContent + Details
Name: | us-gaap_ComprehensiveIncomeNoteTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration