XML 86 R72.htm IDEA: XBRL DOCUMENT
v3.22.4

Net Assets - Narrative (Details) - USD ($) $ in Thousands |  | 12 Months Ended
--- | --- | ---
Nov. 03, 2021 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Investment Company, Changes in Net Assets [Line Items] |  |  |  |
Offering expenses |  | $ 204 | $ 205 | $ 278
Sale of stock, remaining amount available for issuance and sale |  | $ 196,938 | $ 237,384 |
ATM Offering |  |  |  |
Investment Company, Changes in Net Assets [Line Items] |  |  |  |
Sale of stock, issuance amount | $ 250,000 |  |  |
Sale of stock, number of shares issued (in shares) |  | 2,950,300 | 914,175 |
Sale of stock, consideration received |  | $ 40,007 | $ 12,427 |
Offering expenses |  | $ 439 | $ 189 |

X
- Definition Sale Of Stock, Maximum Issuance, Amount + References No definition available. + Details
Name: | nmfc_SaleOfStockMaximumIssuanceAmount
Namespace Prefix: | nmfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Sale Of Stock, Remaining Stock Available For Issuance, Amount + References No definition available. + Details
Name: | nmfc_SaleOfStockRemainingStockAvailableForIssuanceAmount
Namespace Prefix: | nmfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition The cash outflow for cost incurred directly with the issuance of an equity security. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsOfStockIssuanceCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Cash received on stock transaction after deduction of issuance costs. + References No definition available. + Details
Name: | us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of shares issued or sold by the subsidiary or equity method investee per stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=nmfc_AtTheMarketOfferingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |