SUPPLEMENTAL FINANCIAL STATEMENT INFORMATION- Schedule of Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2026	Jan. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Loss contingency reserves	$ 8,934	$ 8,120
Deferred tax liability	1,007	7,655
Taxes payable for unrecognized tax benefits	2,866	2,288
Redeemable convertible preferred stock warrant liability	0	427
NOW Scheme contingency payable	4,338	3,806
Other non-current liabilities	821	653
Total other non-current liabilities	$ 17,966	$ 22,949

Accrued Employment Taxes, Noncurrent

No definition available.

Name:	navn_AccruedEmploymentTaxesNoncurrent
Namespace Prefix:	navn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Redeemable Convertible Preferred Stock Warrant Liability, Noncurrent

+ References

No definition available.

+ Details

Name:	navn_RedeemableConvertiblePreferredStockWarrantLiabilityNoncurrent
Namespace Prefix:	navn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unrecognized Tax Benefits, Payable, Noncurrent

+ References

No definition available.

+ Details

Name:	navn_UnrecognizedTaxBenefitsPayableNoncurrent
Namespace Prefix:	navn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred tax liability attributable to taxable temporary differences, after deferred tax asset, and other tax liabilities expected to be paid after one year or operating cycle, if longer.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredIncomeTaxesAndOtherTaxLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of liability from government assistance, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

Name:	us-gaap_GovernmentAssistanceLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

+ References

+ Details

Name:	us-gaap_OtherLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Obligations not otherwise itemized or categorized in the footnotes to the financial statements that are expected to be paid after one year (or the normal operating cycle, if longer), from the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(24))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

+ Details

Name:	us-gaap_OtherSundryLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant