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Residential Mortgage Securities and MSR Related Assets (MSR-Related Assets - Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Mar. 31, 2018 | Dec. 31, 2016
Term notes backed by MSR-related collateral |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |
Term notes backed by MSR-related collateral | $ 1,157,463 | $ 538,499 |  |
Amortized costs | 1,200,000 | 538,500 |  |
Gross unrealized gains | $ 5,200 | $ 7 |  |
Weighted average yield | 4.75% | 5.32% |  |
Weighted average to maturity | 5 years 3 months 18 days | 4 years 8 months 12 days |  |
Corporate Loan |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |
Commitment to lend |  | $ 100,000 |  | $ 130,000
Amount drawn | $ 59,500 |  | $ 124,200 |
Interest coupon rate | 5.14% |  |  |
Remaining term | 8 months |  |  |
Commitment period on undrawn amount | 8 months |  |  |
Minimum | Corporate Loan |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |
Financing Receivable, Commitment Fee Income Rate | 0.25% |  |  |
Maximum | Corporate Loan |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |
Financing Receivable, Commitment Fee Income Rate | 1.00% |  |  |

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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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