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Securities, Gains and (Losses) on Equity Securities (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 USD ($) Issuer | Dec. 31, 2019 USD ($) Issuer
Gains (losses) on equity securities [Abstract] |  |
Net (losses) and gains recognized on equity securities | $ (414) | $ 4,280
Less: Net gains recognized during the period on equity securities sold during the period | 0 | 3,966
Unrealized (losses) and gains recognized on equity securities still held | (414) | 314
Equity Securities without Readily Determinable Fair Value, Annual Amount [Abstract] |  |
Carrying amount of equity securities without readily determinable fair values | 2,000 | 4,000
Impairment adjustments of equity securities without readily determinable fair values | 0 | 0
Downward adjustments of equity securities without readily determinable fair values | 0 | 0
Upward adjustments of equity securities without readily determinable fair values | $ 0 | $ 0
Number of issuers whose holdings exceeded 10% of consolidated stockholders' equity, excluding U.S. Government securities | Issuer | 0 | 0
Visa Class B Common Stock [Member] |  |
Equity Securities without Readily Determinable Fair Value, Annual Amount [Abstract] |  |
Gain from sale of equity securities without readily determinable fair value |  | $ 4,000

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- Definition Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117546-209714 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(d)) -URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 + Details
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