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Debt Securities Available-for-Sale - Gross Unrealized Losses on Mortgage-Backed Securities (Details) - USD ($) $ in Thousands | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Unrealized losses, less than 12 months | $ 2,065 | $ 975
Estimated fair value, less than 12 months | 193,449 | 201,038
Unrealized losses, 12 months or more | 326 | 2,017
Estimated fair value, 12 months or more | 25,034 | 125,378
Unrealized losses, total | 2,391 | 2,992
Estimated fair value, total | 218,483 | 326,416
GSE | Pass-through Certificates |  |
Debt Securities, Available-for-sale [Line Items] |  |
Unrealized losses, less than 12 months | 4 | 25
Estimated fair value, less than 12 months | 109 | 3,404
Unrealized losses, 12 months or more | 77 | 729
Estimated fair value, 12 months or more | 634 | 55,184
Unrealized losses, total | 81 | 754
Estimated fair value, total | 743 | 58,588
GSE | Real estate mortgage investment conduits (REMICs) |  |
Debt Securities, Available-for-sale [Line Items] |  |
Unrealized losses, less than 12 months | 665 | 950
Estimated fair value, less than 12 months | 135,392 | 197,634
Unrealized losses, 12 months or more | 247 | 1,275
Estimated fair value, 12 months or more | 24,351 | 54,555
Unrealized losses, total | 912 | 2,225
Estimated fair value, total | 159,743 | 252,189
Non-GSE | Real estate mortgage investment conduits (REMICs) |  |
Debt Securities, Available-for-sale [Line Items] |  |
Unrealized losses, less than 12 months | 0 | 0
Estimated fair value, less than 12 months | 0 | 0
Unrealized losses, 12 months or more | 2 | 0
Estimated fair value, 12 months or more | 49 | 53
Unrealized losses, total | 2 | 0
Estimated fair value, total | 49 | 53
Corporate bonds | Other debt obligations |  |
Debt Securities, Available-for-sale [Line Items] |  |
Unrealized losses, less than 12 months | 1,396 | 0
Estimated fair value, less than 12 months | 57,948 | 0
Unrealized losses, 12 months or more | 0 | 13
Estimated fair value, 12 months or more | 0 | 15,586
Unrealized losses, total | 1,396 | 13
Estimated fair value, total | $ 57,948 | $ 15,586

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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922890-210455 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456 + Details
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- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922890-210455 + Details
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