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Residential Mortgage Securities and MSR Related Assets (MSR-Related Assets - Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Term Notes backed by MSR Related Collateral |  |
Debt Securities, Available-for-sale [Line Items] |  |
Term notes backed by MSR related collateral | $ 238,999 | $ 1,157,463
Amortized costs | 184,900 | 1,200,000
Gross unrealized gains | $ 54,000 | $ 5,200
Weighted average yield | 12.30% | 4.75%
Weighted average to maturity | 9 years 2 months 12 days | 5 years 3 months 18 days
Proceeds from Sale of Mortgage Servicing Rights (MSR) | $ 711,700 |
Gross realized losses | 28,700 |
Impairment | 280,800 |
Corporate Loan |  |
Debt Securities, Available-for-sale [Line Items] |  |
Commitment to lend |  | $ 32,600
Amount drawn | $ 0 |
Minimum | Corporate Loan |  |
Debt Securities, Available-for-sale [Line Items] |  |
Commitment fee income rate | 0.25% |
Maximum | Corporate Loan |  |
Debt Securities, Available-for-sale [Line Items] |  |
Commitment fee income rate | 1.00% |

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- Definition Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, Amortized Costs + References No definition available. + Details
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- Definition The fair value as of the balance sheet date of firm holdings in mortgages, mortgage backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the mortgage backed security) and asset-backed securities that are primarily paid from the cash flows of a discrete pool of receivables or other financial assets (such as credit-card receivables), either fixed or revolving, that by their terms convert into cash within a finite time period. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
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- Definition The cash inflow from the sale of servicing rights, which contractually entitle the servicer to receive fees and ancillary revenues for performing billing, collection, disbursement and recordkeeping services in connection with a mortgage portfolio. Rights may be obtained via (1) acquisition or assumption of a servicing obligation that does not relate to financial assets of the servicer or its consolidated affiliates; or (2) by originating mortgage loans and then (a) transferring the loans to a Variable Interest Entity (VIE) in a transaction that meets the necessary transfer and classification requirements, or (b) transferring the loans in a transaction that meets the requirements for sale accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719 + Details
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