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Debt Securities Available-for-Sale - Comparative Summary Of Mortgage-Backed Securities And Other Securities Available-for-Sale (Details) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | $ 1,205,516 | $ 1,246,673
Gross unrealized gains | 7,824 | 18,862
Gross unrealized losses | (5,103) | (730)
Estimated fair value | 1,208,237 | 1,264,805
U.S. Government agency securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 2,344 | 3,168
Gross unrealized gains | 0 | 0
Gross unrealized losses | (54) | (10)
Estimated fair value | 2,290 | 3,158
Pass-through certificates | GSE |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 579,035 | 270,867
Gross unrealized gains | 5,233 | 10,720
Gross unrealized losses | (2,862) | (244)
Estimated fair value | 581,406 | 281,343
Real estate mortgage investment conduits (REMICs) |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 969,790 | 1,155,285
Gross unrealized gains | 7,631 | 17,747
Gross unrealized losses | (4,305) | (720)
Estimated fair value | 973,116 | 1,172,312
Real estate mortgage investment conduits (REMICs) | GSE |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 390,755 | 884,414
Gross unrealized gains | 2,398 | 7,027
Gross unrealized losses | (1,443) | (476)
Estimated fair value | 391,710 | 890,965
Real estate mortgage investment conduits (REMICs) | Non-GSE |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost |  | 4
Gross unrealized gains |  | 0
Gross unrealized losses |  | 0
Estimated fair value |  | 4
Other debt securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 233,382 | 88,220
Gross unrealized gains | 193 | 1,115
Gross unrealized losses | (744) | 0
Estimated fair value | 232,831 | 89,335
Other debt securities | Municipal bonds |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 71 | 122
Gross unrealized gains | 1 | 1
Gross unrealized losses | 0 | 0
Estimated fair value | 72 | 123
Other debt securities | Corporate bonds |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost | 233,311 | 87,319
Gross unrealized gains | 192 | 1,099
Gross unrealized losses | (744) | 0
Estimated fair value | $ 232,759 | 88,418
Other debt securities | Asset-backed securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized cost |  | 779
Gross unrealized gains |  | 15
Gross unrealized losses |  | 0
Estimated fair value |  | $ 794

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- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 + Details
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- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 + Details
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