XML 87 R77.htm IDEA: XBRL DOCUMENT
v3.23.3

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Income Tax Disclosure [Abstract] |  |
TRA liability | $ 9,376 | $ 0

X
- Definition Tax Receivable Agreement, Liability + References No definition available. + Details
Name: | npwr_TaxReceivableAgreementLiability
Namespace Prefix: | npwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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