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Investment Securities - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Dec. 31, 2019
Marketable Securities [Abstract] |  |  |  |  |
Debt securities, AFS, accrued interest receivable | $ 12.4 |  | $ 12.4 |  |
Carrying amount of equity investments without a readily determinable fair value | 24.7 |  | 24.7 |  | $ 25.6
Unrealized gain (loss) for equity investments with readily determinable fair values | $ 4.8 | $ 1.2 | $ (0.9) | $ 4.6 |

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- Definition Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss + References No definition available. + Details
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- Definition Amount of unrealized gain (loss) on 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=116654751&loc=SL75117546-209714 + Details
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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=116654751&loc=SL75117539-209714 + Details
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