Organization and Nature of Business Operations	12 Months Ended
Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Business Operations	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, formerly known as ARMOUR Residential Management LLC. On December 19, 2014, ARMOUR Residential Management LLC, our external manager under the Management Agreement, changed its name to ARMOUR Capital Management LP and converted from a Delaware limited liability company to a Delaware limited partnership and continued as the manager under the same Management Agreement (the "Conversion"). We are an externally managed Maryland corporation incorporated in 2008, managed by ACM, an investment advisor registered with the SEC (see Note 9, "Commitments and Contingencies" and Note 14, “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"). We also may invest in other securities backed by residential mortgages for which the payment of principal and interest is not guaranteed by a GSE or government agency (collectively, "Non-Agency Securities"). While we remain committed to investing in Agency Securities for so long as an adequate supply and pricing exists, we have the flexibility to invest in Non-Agency Securities and respond to changes in GSE policy as needed. At December 31, 2014 and December 31, 2013, Agency Securities accounted for 100% of our securities portfolio. It is expected that the percentage will continue to be 100% or close thereto. Our securities 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”). We have elected to be taxed as a REIT under the Internal Revenue Code (“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.

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, formerly known as ARMOUR Residential Management LLC. On December 19, 2014, ARMOUR Residential Management LLC, our external manager under the Management Agreement, changed its name to ARMOUR Capital Management LP and converted from a Delaware limited liability company to a Delaware limited partnership and continued as the manager under the same Management Agreement (the "Conversion").

We are an externally managed Maryland corporation incorporated in 2008, managed by ACM, an investment advisor registered with the SEC (see Note 9, "Commitments and Contingencies" and Note 14, “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"). We also may invest in other securities backed by residential mortgages for which the payment of principal and interest is not guaranteed by a GSE or government agency (collectively, "Non-Agency Securities"). While we remain committed to investing in Agency Securities for so long as an adequate supply and pricing exists, we have the flexibility to invest in Non-Agency Securities and respond to changes in GSE policy as needed. At December 31, 2014 and December 31, 2013, Agency Securities accounted for 100% of our securities portfolio. It is expected that the percentage will continue to be 100% or close thereto. Our securities 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”).

We have elected to be taxed as a REIT under the Internal Revenue Code (“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.