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Capital and Liquidity Requirements - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2017
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Percentage of Freddie Mac's liquidity requirement of outstanding principal of TAH loans serviced | 8.00% |
Other Assets [Member] |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Outstanding borrower advances | $ 0.1 | $ 0.1
Seller/Servicer Agreements [Member] |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Amount of capital in excess of aggregate regulatory requirements | $ 426.0 |

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- Definition Outstanding borrower advances to investors. + References No definition available. + Details
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- Definition Percentage of liquidity requirement of outstanding principal of targeted affordable housing loans serviced. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The amount by which the company's Total Capital exceeds the minimum required for capital adequacy purposes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958568-112826 + Details
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- Details
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- Details
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