XML 100 R53.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Investment Securities Available For Sale - Summary (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | $ 1,980,415 | $ 1,534,389
Unrealized Gains | 35,721 | 17,989
Unrealized Losses | (9,996) | (40,126)
Fair Value | $ 2,006,140 | $ 1,512,252
Agency ARMs |  |
Debt Securities, Available-for-sale [Line Items] |  |
Weighted average reset period | 26 months | 31 months
Agency RMBS: |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | $ 922,976 | $ 1,076,006
Unrealized Gains | 7,410 | 8
Unrealized Losses | (7,509) | (38,284)
Fair Value | 922,877 | 1,037,730
Unrealized gains (losses), net | (100) |
Agency RMBS: | Unrealized gains (losses) , net |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fair Value | 21,000 |
Agency RMBS: | Agency ARMs |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 55,740 | 73,949
Unrealized Gains | 13 | 8
Unrealized Losses | (1,347) | (2,563)
Fair Value | 54,406 | 71,394
Agency RMBS: | Agency Fixed-Rate |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 867,236 | 1,002,057
Unrealized Gains | 7,397 | 0
Unrealized Losses | (6,162) | (35,721)
Fair Value | 868,471 | 966,336
Agency CMBS |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 51,334 | 0
Unrealized Gains | 19 | 0
Unrealized Losses | (395) | 0
Fair Value | 50,958 | 0
Unrealized gains (losses), net | (400) |
Agency CMBS | Unrealized gains (losses) , net |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fair Value | 30,700 |
Total Agency |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 974,310 | 1,076,006
Unrealized Gains | 7,429 | 8
Unrealized Losses | (7,904) | (38,284)
Fair Value | 973,835 | 1,037,730
Non-Agency RMBS |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 701,583 | 215,337
Unrealized Gains | 14,992 | 166
Unrealized Losses | (1,261) | (1,466)
Fair Value | 715,314 | 214,037
Unrealized gains (losses), net | 1,200 |
Non-Agency RMBS | Unrealized gains (losses) , net |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fair Value | 123,800 |
CMBS |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 254,620 | 243,046
Unrealized Gains | 13,300 | 17,815
Unrealized Losses | (143) | (376)
Fair Value | 267,777 | 260,485
Unrealized gains (losses), net | 500 |
Investment securities held in securitization |  | 52,700
CMBS | Unrealized gains (losses) , net |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fair Value | 20,600 |
ABS |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 49,902 | 0
Unrealized Gains | 0 | 0
Unrealized Losses | (688) | 0
Fair Value | 49,214 | $ 0
Unrealized gains (losses), net | (700) |
ABS | Unrealized gains (losses) , net |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fair Value | $ 49,200 |

X
- Definition Debt Securities, Available-for-sale, Weighted Average Reset Period + References No definition available. + Details
Name: | nymt_DebtSecuritiesAvailableForSaleWeightedAverageResetPeriod
Namespace Prefix: | nymt_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(b)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_AssetsHeldInTrust
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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 No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
Name: | us-gaap_UnrealizedGainLossOnInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=nymt_AgencyARMsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=nymt_AgencyResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=nymt_UnrealizedGainsLossesOnInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=nymt_AgencyFixedRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=nymt_AgencyCMBSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AgencySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=nymt_NonAgencyRMBSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=nymt_CMBSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |