Lessee, Finance Lease, Number Of Office Trailers

No definition available.

Name:	npwr_LesseeFinanceLeaseNumberOfOfficeTrailers
Namespace Prefix:	npwr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Lessee, Operating Lease, Number Of Extension Periods

+ References

No definition available.

+ Details

Name:	npwr_LesseeOperatingLeaseNumberOfExtensionPeriods
Namespace Prefix:	npwr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating Lease, Annual Lease Payment

+ References

No definition available.

+ Details

Name:	npwr_OperatingLeaseAnnualLeasePayment
Namespace Prefix:	npwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Operating Lease, Early Termination, Term

+ References

No definition available.

+ Details

Name:	npwr_OperatingLeaseEarlyTerminationTerm
Namespace Prefix:	npwr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeFinanceLeaseTermOfContract1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-7A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeLeaseDescriptionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=npwr_MeasurementBuildingLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=npwr_RoneyStLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=npwr_AtlasTowerLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=npwr_OfficeTrailerLeasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Leases - Narrative (Details)		12 Months Ended
Leases - Narrative (Details)	Mar. 08, 2024 tranche	Dec. 31, 2025 USD ($)	Mar. 07, 2025	Jun. 26, 2024 office_trailer	Feb. 28, 2024	Oct. 06, 2023	Jun. 06, 2022
Measurement Building Lease
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract							60 months
Roney St. Lease
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract						62 months
Operating lease, early termination, term		50 months
Atlas Tower Lease
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract					68 months
Operating lease, early termination, term		44 months
Building
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract			62 months
Lessee, operating lease, renewal term			5 years
Land Lease
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract	60 months
Lessee, operating lease, renewal term	10 years
Lessee, operating lease, number of extension periods \| tranche	3
Operating lease, annual lease payment \| $		$ 1
Office Trailers
Lessee, Lease, Description [Line Items]
Lessee, finance lease, number of office trailers \| office_trailer				2
Lessee, finance lease, term of contract				24 months