Represents the weighted average life of the available for sale securities portfolio.

No definition available.

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Namespace Prefix:	nymt_
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- Definition

Contractual maturities of investments.

+ References

No definition available.

+ Details

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Namespace Prefix:	nymt_
Data Type:	xbrli:durationItemType
Balance Type:	na
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- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

+ Details

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

- Definition

The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8B

-URI http://asc.fasb.org/extlink&oid=27724398&loc=SL6284393-111563

+ Details

Name:	us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26853-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

+ Details

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Balance Type:	debit
Period Type:	duration

Note 3 - Investment Securities Available for Sale (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Note 3 - Investment Securities Available for Sale (Details) [Line Items]
Proceeds from Sale of Available-for-sale Securities	$ 41,400,000	$ 0	$ 41,442,000	$ 1,254,000
Available-for-sale Securities, Gross Realized Gain (Loss)	16,500,000		16,500,000	(100,000)
Available For Sale Securities Portfolio Life			4 years 302 days		7 years 10 days
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	$ 0	$ 200,000	$ 0	$ 200,000
CMBS [Member] \| Minimum [Member]
Note 3 - Investment Securities Available for Sale (Details) [Line Items]
Contractual Maturities			0 years
CMBS [Member] \| Maximum [Member]
Note 3 - Investment Securities Available for Sale (Details) [Line Items]
Contractual Maturities			10 years
Maximum [Member]
Note 3 - Investment Securities Available for Sale (Details) [Line Items]
Contractual Maturities			30 years