v3.26.1
Cover
Aug. 01, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Aug. 01, 2026
Entity File Number 811-22329
Entity Registrant Name Nuveen Mortgage and Income Fund
Entity Central Index Key 0001472215
Entity Tax Identification Number 27-1094170
Entity Incorporation, State or Country Code MA
Entity Address, Address Line One 333 West Wacker Drive
Entity Address, City or Town Chicago
Entity Address, State or Province IL
Entity Address, Postal Zip Code 60606
City Area Code (312)
Local Phone Number 917-7700
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Shares of Beneficial
Trading Symbol JLS
Security Exchange Name NYSE
Entity Emerging Growth Company false