Organization	12 Months Ended
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization MFA Financial, Inc. (the “Company”) was incorporated in Maryland on July 24, 1997 and began operations on April 10, 1998. The Company has elected to be treated as a real estate investment trust (“REIT”) for U.S. federal income tax purposes. In order to maintain its qualification as a REIT, the Company must comply with a number of requirements under federal tax law, including that it must distribute at least 90% of its annual REIT taxable income to its stockholders. The Company has elected to treat certain of its subsidiaries as a taxable REIT subsidiary (“TRS”). In general, a TRS may hold assets and engage in activities that the Company cannot hold or engage in directly and generally may engage in any real estate or non-real estate related business. (See Notes 2(o)

Organization

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

MFA Financial, Inc. (the “Company”) was incorporated in Maryland on July 24, 1997 and began operations on April 10, 1998. The Company has elected to be treated as a real estate investment trust (“REIT”) for U.S. federal income tax purposes. In order to maintain its qualification as a REIT, the Company must comply with a number of requirements under federal tax law, including that it must distribute at least 90% of its annual REIT taxable income to its stockholders. The Company has elected to treat certain of its subsidiaries as a taxable REIT subsidiary (“TRS”). In general, a TRS may hold assets and engage in activities that the Company cannot hold or engage in directly and generally may engage in any real estate or non-real estate related business. (See Notes 2(o)