Name:	newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesFromOtherAssetClass
Namespace Prefix:	newt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Reclassification of Loans

No definition available.

Name:	newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoans
Namespace Prefix:	newt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Return On Investment

No definition available.

Name:	newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReturnOnInvestment
Namespace Prefix:	newt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Value after Conversion

No definition available.

Name:	newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueAfterConversion
Namespace Prefix:	newt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-SubTopic 10
-Topic 820
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Indicates line item in statement in which net income is reported that includes gain (loss) from asset measured at fair value using unobservable input (level 3).

Name:	us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_IncomeStatementLocationAxis=newt_DebtAndEquitySecuritiesUnrealizedGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_IncomeStatementLocationAxis=newt_UnrealizedGainLossOnServicingAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	newt_NatureOfGainLossAxis=newt_ChangesInValuationInputsOrAdjustmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	newt_NatureOfGainLossAxis=newt_FactorsOtherThanChangesInValuationInputsOrAdjustmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_IncomeStatementLocationAxis=newt_DebtAndEquitySecuritiesRealizedGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=newt_LoansHeldForInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=newt_LoansHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancialInstrumentAxis=newt_ConventionalLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_InvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InvestmentIssuerAffiliationAxis=us-gaap_InvestmentAffiliatedIssuerControlledMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InvestmentIssuerAffiliationAxis=us-gaap_OtherControlledCompaniesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InvestmentIssuerAffiliationAxis=us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=newt_ServicingAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_WarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: