XML 135 R33.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Shareholders' Equity (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2019
Stockholders' Equity Note [Abstract] |
Schedule of common and preferred stock activity | The Common and Preferred Stock Activity table below contains additional information about preferred stock conversions during 2019, 2018 and 2017:
Common and Preferred Stock Activity: | Preferred Stock |  | Common stock
(in shares) | Series A Convertible |  | Treasury |  | Outstanding
Beginning balance as of December 31, 2016 | 75,625 |  |  | 7,186,521 |  |  | 87,250,897 |
Repurchase of common stock | — |  |  | — |  |  | — |
Conversion of convertible preferred stock | (1,261 | ) |  | — |  |  | 126,098 |
Issuance for share-based compensation plans | — |  |  | — |  |  | 167,782 |
Ending balance as of December 31, 2017 | 74,364 |  |  | 7,186,521 |  |  | 87,544,777 |
Repurchase of common stock | — |  |  | — |  |  | — |
Conversion of convertible preferred stock | (2,397 | ) |  | — |  |  | 239,748 |
Issuance for share-based compensation plans | — |  |  | — |  |  | 318,915 |
Balance as of December 31, 2018 | 71,967 |  |  | 7,186,521 |  |  | 88,103,440 |
Repurchase of common stock | — |  |  | — |  |  | — |
Conversion of convertible preferred stock | (4,644 | ) |  | — |  |  | 464,431 |
Issuance for share-based compensation plans | — |  |  | — |  |  | 617,790 |
Ending balance as of December 31, 2019 | 67,323 |  |  | 7,186,521 |  |  | 89,185,661 |

X
- Definition Tabular disclosure of the change in preferred stock, treasury stock and common stock outstanding. + References No definition available. + Details
Name: | cenx_ScheduleOfCommonandPreferredStockRollForwardTableTextBlock
Namespace Prefix: | cenx_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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