Investment Securities Available For Sale, at Fair Value - Weighted Average Life (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
0 to 5 years	$ 604,459	$ 283,554
Over 5 to 10 years	2,923,871	1,727,269
10+ years	300,214	2,994
Total	$ 3,828,544	$ 2,013,817

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

No definition available.

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