2.4.0.81010 - Disclosure - Organizationtruefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0001465885duration2013-01-01T00:00:002013-06-30T00:00:001true 1us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization2false 2us-gaap_NatureOfOperationsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-size:10.0pt;font-family:Times New Roman;"> Note 1 — Organization   Western Asset Mortgage Capital Corporation (is referred to throughout this report as the “Company”) is a residential real estate finance company that invests in residential mortgage assets in the United States.  The Company is primarily focused on investing in, financing and managing Agency RMBS. Although the Company’s core investment strategy is focused on Agency RMBS, the Company has opportunistically supplemented its portfolio with Non-Agency RMBS and may, in the future, opportunistically invest in commercial mortgage-backed securities (“CMBS”) and asset-backed securities (“ABS”).   The Company is externally managed by Western Asset Management Company (“WAM”, or the “Manager”), an investment advisor registered with the Securities and Exchange Commission (“SEC”). WAM is a wholly-owned subsidiary of Legg Mason, Inc.  The Company intends to elect and qualify to be taxed as a real estate investment trust or “REIT” commencing with its taxable year ended December 31, 2012.   At December 31, 2011 and through May 14, 2012, the Company complied with the reporting requirements for development stage enterprises and was subject to the risks associated with development stage enterprises. The Company completed its initial public offering and began its core operation on May 15, 2012. The Company incurred organizational, accounting and offering costs in connection with the Company’s initial public offering (the “IPO”) of its common stock and concurrent private placements. In accordance with the Management Agreement (as defined herein in Note 10) between the Company and the Manager, the Company reimbursed the Manager for $1.2 million of offering and other related organization costs, which were paid by the Manager, from the proceeds of the IPO and concurrent private placements. The Manager paid all costs in excess of $1.2 million. The Company ceased reporting as a development stage company on May 15, 2012. </div>falsefalsefalsenonnum:textBlockItemTypenaThe entire disclosure for the nature of an entity's business, the major products or services it sells or provides and its principal markets, including the locations of those markets. If the entity operates in more than one business, the disclosure also indicates the relative importance of its operations in each business and the basis for the determination (for example, assets, revenues, or earnings).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6003-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 94-6 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false0OrganizationfalseOrganizationUnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.westernassetmcc.com/role/DisclosureOrganization12