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Mortgage-Backed Securities - Realize Gain (Loss) on Investments (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Investments [Line Items] |  |  |
Proceeds Received | $ 325,282 | $ 4,642,305 | $ 1,033,066
Realized Gain (Loss) | 6,705 | 308,084 | (5,755)
Agency MBS | Agency RMBS-designated as AFS |  |  |
Investments [Line Items] |  |  |
Proceeds Received | 287,409 | 2,395,032 | 796,699
Realized Gain (Loss) | 3,938 | 82,689 | 506
Agency MBS | Agency CMBS-designated as AFS |  |  |
Investments [Line Items] |  |  |
Proceeds Received | 37,873 | 2,247,273 | 213,199
Realized Gain (Loss) | 2,767 | 225,395 | (6,493)
Agency MBS | Agency CMBS IO -designated as AFS |  |  |
Investments [Line Items] |  |  |
Proceeds Received | 0 | 0 | 23,168
Realized Gain (Loss) | $ 0 | $ 0 | $ 232

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- Definition Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563 + Details
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