XML 108 R93.htm IDEA: XBRL DOCUMENT v3.8.0.1

Derivative Instruments and Hedging Activities - Components of Realized and Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gains (Losses)	$ 268	$ 1,192	$ (1,051)	$ 1,546	$ 2,875	$ 6,416	$ 26	$ 5,548	$ 1,955	$ 7,070	$ (2,641)
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)									3,939	(1,244)	(6,708)
Unrealized Gains (Losses)									(148)	3,057	(2,700)
TBA Securities | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)									2,511	3,998	5,244
Unrealized Gains (Losses)									(141)	534	(2,253)
Eurodollar futures | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)									1,379	(3,202)	(2,321)
Unrealized Gains (Losses)									(1,175)	2,417	(342)
Interest rate swaps | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)									(218)	0	0
Unrealized Gains (Losses)									1,231	(126)	(26)
Swaptions | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)									0	0	0
Unrealized Gains (Losses)									274	568	(658)
U.S. Treasury and interest rate swap futures and options | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)									267	(2,040)	(9,631)
Unrealized Gains (Losses)									$ (337)	$ (336)	$ 579

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

X

- Definition

The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13(h))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnSaleOfDerivatives
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

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

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=nymt_TBASecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EurodollarFutureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_SwaptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=nymt_OptionsOnUSTreasuryFuturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: