Represents the share to be issued upon exchange of each share.

No definition available.

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Namespace Prefix:	svsvu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
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- Definition

Represents the value of shares issued contingent on closing of the Merger.

+ References

No definition available.

+ Details

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Namespace Prefix:	svsvu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the value of shares issued contingent on entry into definitive documents.

+ References

No definition available.

+ Details

Name:	svsvu_ValueOfSharesIssuedContingentOnEntryIntoDefinitiveDocuments
Namespace Prefix:	svsvu_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Aggregate cash proceeds received from a combination of transactions in which noncurrent assets are sold, which may include the sale of a business, an investment in an affiliate (including an equity method investee), property, plant and equipment and intangible assets. Excludes sales of trading, available-for-sale, and held-to-maturity securities.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Period Type:	duration

- Details

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
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- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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Merger with Spring Valley (Details) - USD ($) $ in Thousands	May 02, 2022	Mar. 31, 2022	Dec. 31, 2021
Subscription Agreements
Subsequent Event [Line Items]
Value of shares issued contingent on closing of the Merger		$ 211,000	$ 211,000
Value of shares issued contingent on entry into definitive documents		$ 30,000	$ 30,000
Class A Common Stock
Subsequent Event [Line Items]
Share exchange ratio		1	1
Class B ordinary share
Subsequent Event [Line Items]
Share exchange ratio		1	1
Subsequent Event
Subsequent Event [Line Items]
Proceeds from merger	$ 341,000