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Fair Value of Financial Instruments - Narrative (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair value option | $ 0 | $ 0
Non-marketable equity securities held in other financial institutions | 45,192,000 | 62,586,000
Impairment recorded on investments in equity securities that do not have readily determinable fair values | 0 |
Liability to repurchase past due GNMA loans | 43,400,000 | 55,500,000
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair value of impaired loans | 4,800,000 | 12,300,000
Foreclosed assets | 1,500,000 | $ 1,600,000
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3 | Residential real estate | Real estate |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential mortgage loans in the process of foreclosure | $ 5,900,000 |
Minimum | Measurement Input, Credit Spread |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Credit spread, securities at fair value through income | 0.83% | 0.83%
Credit spread, loans held-for-investment |  | 2.90%
Maximum | Measurement Input, Credit Spread |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Credit spread, securities at fair value through income | 2.27% | 2.27%
Credit spread, loans held-for-investment |  | 4.13%

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- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714 + Details
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- Definition This item represents the aggregate fair value of loans held as assets that are in nonaccrual status for which the fair value option has been elected, if the entity's policy is to recognize interest income separately from other changes in fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (e)(2) -URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 + Details
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