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Shareholders' Deficit - Preferred Stock Shares (Details) - $ / shares | Mar. 31, 2022 | Dec. 31, 2021 | Mar. 31, 2021 | Dec. 31, 2020 | Sep. 30, 2020 | Aug. 31, 2020 | Dec. 31, 2019
--- | --- | --- | --- | --- | --- | --- | ---
Temporary Equity [Line Items] |  |  |  |  |  |  |
Temporary equity, shares outstanding | 6,000,000 | 6,000,000 | 6,000,000 | 6,000,000 |  |  | 6,000,000
SPRING VALLEY ACQUISITION CORP |  |  |  |  |  |  |
Temporary Equity [Line Items] |  |  |  |  |  |  |
Preferred shares, shares authorized | 1,000,000 | 1,000,000 |  | 1,000,000 | 1,000,000 | 1,000,000 |
Preferred stock, par value, (per share) | $ 0.0001 | $ 0.0001 |  | $ 0.0001 | $ 0.0001 | $ 0.0001 |
Preferred shares, shares issued | 0 | 0 |  | 0 | 0 | 0 |
Preferred shares, shares outstanding | 0 | 0 |  | 0 | 0 | 0 |
Class A Common Stock | SPRING VALLEY ACQUISITION CORP |  |  |  |  |  |  |
Temporary Equity [Line Items] |  |  |  |  |  |  |
Temporary equity, shares outstanding | 23,000,000 | 23,000,000 |  |  |  |  |
Class A Ordinary Shares Subject to Possible Redemption. | SPRING VALLEY ACQUISITION CORP |  |  |  |  |  |  |
Temporary Equity [Line Items] |  |  |  |  |  |  |
Temporary equity, shares outstanding |  | 23,000,000 |  | 23,000,000 | 23,000,000 | 23,000,000 |

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- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644 + Details
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- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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- Definition Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644 + Details
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- Definition The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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