Investment Securities Available For Sale, at Fair Value - Weighted Average Life (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
0 to 5 years	$ 39,655	$ 144,266
Over 5 to 10 years	46,558	39,306
10+ years	13,346	17,272
Total	$ 99,559	$ 200,844

Debt Securities, Trading, Available-For-Sale, Maturity, Allocated And Single Maturity Date, After Five Through Ten Years, Fair Value

No definition available.

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Namespace Prefix:	nymt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant