Organization and Nature of Business Operations	3 Months Ended
Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Business Operations	Note 2 -Organization and Nature of Business Operations References to “we,” “us,” “our,” “ARMOUR” or the “Company” are to ARMOUR Residential REIT, Inc. References to “ACM” are to ARMOUR Capital Management LP, a Delaware limited partnership. In February 2016, the Company formed JMI Acquisition Corporation (“Acquisition”), a Maryland corporation and wholly-owned subsidiary of ours. Acquisition was formed for the purpose of acquiring all of the shares of common stock of JAVELIN Mortgage Investment Corp. (“JAVELIN”). See Note 17 -Subsequent Events for more information about the relationship between ARMOUR, JAVELIN and Acquisition. We are an externally managed Maryland corporation incorporated in 2008, managed by ACM, an investment advisor registered with the SEC (see Note 10 -Commitments and Contingencies and Note 15 -Related Party Transactions for additional discussion). We invest in residential mortgage backed securities issued or guaranteed by a United States (“U.S.”) Government-sponsored entity (“GSE”), such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac) or guaranteed by the Government National Mortgage Administration (Ginnie Mae) (collectively, “Agency Securities”). Other securities backed by residential mortgages in which we invest, for which the payment of principal and interest is not guaranteed by a GSE or government agency (collectively, “Non-Agency Securities” and together with Agency Securities, “MBS”), may benefit from credit enhancement derived from structural elements such as subordination, over collateralization or insurance. At March 31, 2016 and December 31, 2015, investments in Agency Securities accounted for 97.3% and 100.0% of our MBS portfolio, respectively. During the quarter ended March 31, 2016, we began to invest in Non-Agency Securities. At March 31, 2016, investments in Non-Agency Securities accounted for 2.7% of our MBS portfolio. Our MBS portfolio consists primarily of Agency Securities backed by fixed rate home loans. From time to time, a portion of our assets may be invested in Agency Securities backed by hybrid adjustable rate and adjustable rate home loans as well as unsecured notes and bonds issued by GSEs, U.S. Treasuries and money market instruments, subject to certain income tests we must satisfy for our qualification as a real estate investment trust (“REIT”). Our charter permits us to invest in Agency Securities and Non-Agency Securities. We have elected to be taxed as a REIT under the Internal Revenue Code, as amended (“the Code”). Our qualification as a REIT depends on our ability to meet, on a continuing basis, various complex requirements under the Code relating to, among other things, the sources of our gross income, the composition and values of our assets, our distribution levels and the concentration of ownership of our capital stock. We believe that we are organized in conformity with the requirements for qualification as a REIT under the Code and our manner of operations enables us to meet the requirements for taxation as a REIT for federal income tax purposes. As a REIT, we will generally not be subject to federal income tax on the REIT taxable income that we currently distribute to our stockholders. If we fail to qualify as a REIT in any taxable year and do not qualify for certain statutory relief provisions, we will be subject to federal income tax at regular corporate rates. Even if we qualify as a REIT for federal income tax purposes, we may still be subject to some federal, state and local taxes on our income.

Note 2 -Organization and Nature of Business Operations

References to “we,” “us,” “our,” “ARMOUR” or the “Company” are to ARMOUR Residential REIT, Inc. References to “ACM” are to ARMOUR Capital Management LP, a Delaware limited partnership. In February 2016, the Company formed JMI Acquisition Corporation (“Acquisition”), a Maryland corporation and wholly-owned subsidiary of ours. Acquisition was formed for the purpose of acquiring all of the shares of common stock of JAVELIN Mortgage Investment Corp. (“JAVELIN”). See Note 17 -Subsequent Events for more information about the relationship between ARMOUR, JAVELIN and Acquisition.

We are an externally managed Maryland corporation incorporated in 2008, managed by ACM, an investment advisor registered with the SEC (see Note 10 -Commitments and Contingencies and Note 15 -Related Party Transactions for additional discussion). We invest in residential mortgage backed securities issued or guaranteed by a United States (“U.S.”) Government-sponsored entity (“GSE”), such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac) or guaranteed by the Government National Mortgage Administration (Ginnie Mae) (collectively, “Agency Securities”). Other securities backed by residential mortgages in which we invest, for which the payment of principal and interest is not guaranteed by a GSE or government agency (collectively, “Non-Agency Securities” and together with Agency Securities, “MBS”), may benefit from credit enhancement derived from structural elements such as subordination, over collateralization or insurance. At March 31, 2016 and December 31, 2015, investments in Agency Securities accounted for 97.3% and 100.0% of our MBS portfolio, respectively. During the quarter ended March 31, 2016, we began to invest in Non-Agency Securities. At March 31, 2016, investments in Non-Agency Securities accounted for 2.7% of our MBS portfolio.

Our MBS portfolio consists primarily of Agency Securities backed by fixed rate home loans. From time to time, a portion of our assets may be invested in Agency Securities backed by hybrid adjustable rate and adjustable rate home loans as well as unsecured notes and bonds issued by GSEs, U.S. Treasuries and money market instruments, subject to certain income tests we must satisfy for our qualification as a real estate investment trust (“REIT”). Our charter permits us to invest in Agency Securities and Non-Agency Securities.

We have elected to be taxed as a REIT under the Internal Revenue Code, as amended (“the Code”). Our qualification as a REIT depends on our ability to meet, on a continuing basis, various complex requirements under the Code relating to, among other things, the sources of our gross income, the composition and values of our assets, our distribution levels and the concentration of ownership of our capital stock. We believe that we are organized in conformity with the requirements for qualification as a REIT under the Code and our manner of operations enables us to meet the requirements for taxation as a REIT for federal income tax purposes.

As a REIT, we will generally not be subject to federal income tax on the REIT taxable income that we currently distribute to our stockholders. If we fail to qualify as a REIT in any taxable year and do not qualify for certain statutory relief provisions, we will be subject to federal income tax at regular corporate rates. Even if we qualify as a REIT for federal income tax purposes, we may still be subject to some federal, state and local taxes on our income.