XML 135 R65.htm IDEA: XBRL DOCUMENT
v3.23.3

Net Assets - Roll forward of Net Assets (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Jun. 30, 2023 | Mar. 31, 2023 | Sep. 30, 2022 | Jun. 30, 2022 | Mar. 31, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period (in shares) |  |  | 100,937,026 |  |  |  | 100,937,026 |
Beginning of the period | $ 1,337,962 | $ 1,338,494 | $ 1,326,191 | $ 1,365,201 | $ 1,367,840 | $ 1,342,612 | $ 1,326,191 | $ 1,342,612
Issuances of common stock | 6,625 |  |  | 2,955 | 16,577 | 21,572 |  |
Offering costs | (66) | (91) | (56) | (34) | (74) | (52) |  |
Distributions declared | (36,526) | (35,519) | (32,453) | (30,538) | (34,405) | (33,339) |  |
Contributions related to non-controlling interest in NMNLC |  |  |  |  | 123 |  |  |
Net increase (decrease) in net assets resulting from operations | $ 28,699 | 35,078 | 44,812 | 7,514 | 15,140 | 37,047 | $ 108,589 | 59,701
End of the period (in shares) | 101,439,649 |  |  |  |  |  | 101,439,649 |
Ending of the period | $ 1,336,694 | 1,337,962 | 1,338,494 | 1,345,098 | 1,365,201 | 1,367,840 | $ 1,336,694 | 1,345,098
Total Net Assets of NMFC |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period | 1,326,101 | 1,326,690 | 1,314,473 | 1,351,610 | 1,349,368 | 1,321,245 | 1,314,473 | 1,321,245
Issuances of common stock | 6,625 |  |  | 2,955 | 16,577 | 21,572 |  |
Offering costs | (66) | (91) | (56) | (34) | (74) | (52) | (213) | (160)
Distributions declared | (36,338) | (35,328) | (32,300) | (30,281) | (30,215) | (29,589) | (103,966) | (90,085)
Net increase (decrease) in net assets resulting from operations | 28,696 | 34,830 | 44,573 | 7,705 | 15,954 | 36,192 | 108,099 | 59,851
Ending of the period | $ 1,325,018 | $ 1,326,101 | $ 1,326,690 | $ 1,331,955 | $ 1,351,610 | $ 1,349,368 | $ 1,325,018 | $ 1,331,955
Common Stock |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period (in shares) | 100,937,026 | 100,937,026 | 100,937,026 | 100,716,928 | 99,498,562 | 97,907,441 | 100,937,026 | 97,907,441
Beginning of the period | $ 1,009 | $ 1,009 | $ 1,009 | $ 1,007 | $ 995 | $ 979 | $ 1,009 | $ 979
Issuances of common stock (in shares) | 502,623 |  |  | 220,098 | 1,218,366 | 1,591,121 |  |
Issuances of common stock | $ 5 |  |  | $ 2 | $ 12 | $ 16 |  |
End of the period (in shares) | 101,439,649 | 100,937,026 | 100,937,026 | 100,937,026 | 100,716,928 | 99,498,562 | 101,439,649 | 100,937,026
Ending of the period | $ 1,014 | $ 1,009 | $ 1,009 | $ 1,009 | $ 1,007 | $ 995 | $ 1,014 | $ 1,009
Paid in Capital in Excess of Par |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period | 1,305,798 | 1,305,889 | 1,305,945 | 1,310,791 | 1,294,300 | 1,272,796 | 1,305,945 | 1,272,796
Issuances of common stock | 6,620 |  |  | 2,953 | 16,565 | 21,556 |  |
Offering costs | (66) | (91) | (56) | (34) | (74) | (52) |  |
Ending of the period | 1,312,352 | 1,305,798 | 1,305,889 | 1,313,710 | 1,310,791 | 1,294,300 | 1,312,352 | 1,313,710
Accumulated Net Investment Income |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period | 157,756 | 153,406 | 147,593 | 119,495 | 118,314 | 118,330 | 147,593 | 118,330
Distributions declared | (36,338) | (35,328) | (32,300) | (30,281) | (30,215) | (29,589) |  |
Net increase (decrease) in net assets resulting from operations | 40,445 | 39,678 | 38,113 | 32,527 | 31,396 | 29,573 |  |
Ending of the period | 161,863 | 157,756 | 153,406 | 121,741 | 119,495 | 118,314 | 161,863 | 121,741
Accumulated Net Realized (Losses) Gains |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period | (64,828) | (67,395) | (68,072) | (59,654) | (74,503) | (92,099) | (68,072) | (92,099)
Net increase (decrease) in net assets resulting from operations | 4,673 | 2,567 | 677 | (390) | 14,849 | 17,596 |  |
Ending of the period | (60,155) | (64,828) | (67,395) | (60,044) | (59,654) | (74,503) | (60,155) | (60,044)
Net Unrealized Appreciation (Depreciation) |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period | (73,634) | (66,219) | (72,002) | (20,029) | 10,262 | 21,239 | (72,002) | 21,239
Net increase (decrease) in net assets resulting from operations | (16,422) | (7,415) | 5,783 | (24,432) | (30,291) | (10,977) |  |
Ending of the period | (90,056) | (73,634) | (66,219) | (44,461) | (20,029) | 10,262 | (90,056) | (44,461)
Non-Controlling Interest in NMNLC |  |  |  |  |  |  |  |
Investment Company, Net Assets [Roll Forward] |  |  |  |  |  |  |  |
Beginning of the period | 11,861 | 11,804 | 11,718 | 13,591 | 18,472 | 21,367 | 11,718 | 21,367
Distributions declared | (188) | (191) | (153) | (257) | (4,190) | (3,750) |  |
Contributions related to non-controlling interest in NMNLC |  |  |  |  | 123 |  |  |
Net increase (decrease) in net assets resulting from operations | 3 | 248 | 239 | (191) | (814) | 855 | 490 | (150)
Ending of the period | $ 11,676 | $ 11,861 | $ 11,804 | $ 13,143 | $ 13,591 | $ 18,472 | $ 11,676 | $ 13,143

X
- Definition Stock Issued During Period, Shares, New Issues And Dividend Reinvestment Plan + References No definition available. + Details
Name: | nmfc_StockIssuedDuringPeriodSharesNewIssuesAndDividendReinvestmentPlan
Namespace Prefix: | nmfc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Issued During Period, Value, New Issues And Dividend Reinvestment Plan + References No definition available. + Details
Name: | nmfc_StockIssuedDuringPeriodValueNewIssuesAndDividendReinvestmentPlan
Namespace Prefix: | nmfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of decrease in additional paid in capital (APIC) resulting from direct costs associated with issuing stock. Includes, but is not limited to, legal and accounting fees and direct costs associated with stock issues under a shelf registration. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + 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(29)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of dividend distribution from ordinary income and capital gain. Excludes distribution for tax return of capital. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480767/946-205-45-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480990/946-20-50-8 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480767/946-205-45-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 + Details
Name: | us-gaap_InvestmentCompanyDividendDistribution
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_InvestmentCompanyNetAssetsRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase in noncontrolling interest from subsidiary issuance of equity interests to noncontrolling interest holders. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 23 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481231/810-10-45-23 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (c)(2) -SubTopic 10 -Topic 810 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481203/810-10-50-1A + Details
Name: | us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-28 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480175/815-40-65-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-8 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-9 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-11 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480767/946-205-45-3 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section 45 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483581/946-220-45-7 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(16)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(9)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(1)(d)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 19 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481231/810-10-45-19 Reference 16: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482765/220-10-50-6 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 18: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-30 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 29: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-31 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479557/942-235-S99-1 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-7 Reference 33: http://www.xbrl.org/2003/role/exampleRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 4J -Publisher FASB -URI https://asc.fasb.org//1943274/2147481175/810-10-55-4J Reference 34: http://www.xbrl.org/2003/role/exampleRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 4K -Publisher FASB -URI https://asc.fasb.org//1943274/2147481175/810-10-55-4K Reference 35: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A Reference 36: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B Reference 37: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-2 Reference 38: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481203/810-10-50-1A Reference 39: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481203/810-10-50-1A + Details
Name: | us-gaap_ProfitLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of equity (deficit) attributable to parent and noncontrolling interest. Excludes temporary equity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483421/250-10-45-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 23 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483421/250-10-45-23 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483421/250-10-45-5 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 5 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479654/326-10-65-5 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480528/815-20-65-6 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480528/815-20-65-6 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1)(i) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480528/815-20-65-6 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1)(iii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480528/815-20-65-6 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1)(iv) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480528/815-20-65-6 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (i)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480528/815-20-65-6 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 848 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (a)(3)(iii)(03) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483550/848-10-65-2 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 105 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479343/105-10-65-6 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 105 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479343/105-10-65-6 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (f)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (f)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 8 -Subparagraph (d)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482615/740-10-65-8 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 8 -Subparagraph (d)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482615/740-10-65-8 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 4 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479654/326-10-65-4 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 15 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480336/718-10-65-15 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 15 -Subparagraph (f)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480336/718-10-65-15 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 15 -Subparagraph (f)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480336/718-10-65-15 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-1 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (e)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480175/815-40-65-1 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-7 Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482765/220-10-50-5 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481674/830-30-50-1 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481694/830-30-45-17 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 20 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481694/830-30-45-20 Reference 29: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-11 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480767/946-205-45-3 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481004/946-505-50-3 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(19)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479617/946-210-S99-2 Reference 34: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 35: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(6)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 36: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 37: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1 Reference 38: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 Reference 39: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 Reference 40: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-28 Reference 41: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481231/810-10-45-15 Reference 42: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 16 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481231/810-10-45-16 Reference 43: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4I -Publisher FASB -URI https://asc.fasb.org//1943274/2147481175/810-10-55-4I + Details
Name: | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_ParentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AdditionalPaidInCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=nmfc_RetainedEarningsAccumulatedNetInvestmentIncomeLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=nmfc_RetainedEarningsAccumulatedNetRealizedGainLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=nmfc_RetainedEarningsNetUnrealizedAppreciationDepreciationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_NoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |