Investment Securities - Non-marketable and Other Securities Additional Information (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) Investment	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) Investment
Investment Holdings [Line Items]
Investments in qualified affordable housing projects, net	$ 616,997		$ 616,188
Other liabilities	372,516		370,208
Tax credits and other tax benefits recognized	28,184	$ 11,759
Amortization expense included in provision for income taxes	16,105	$ 11,471
Fair value accounting \| Unconsolidated venture capital and private equity fund investments
Investment Holdings [Line Items]
Nonmarketable securities	$ 178,407		$ 184,886
Upper Limit
Investment Holdings [Line Items]
Percentage of ownership	5.00%
Non-marketable securities \| Fair value accounting \| Unconsolidated venture capital and private equity fund investments
Investment Holdings [Line Items]
Number of investments \| Investment	161		162

Nonmarketable Securities

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Number of Investments

+ References

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Amount of affordable housing tax credits and other tax benefits recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
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Amount of investment in qualified affordable housing projects.

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Amount of amortization expense of investment in qualified affordable housing projects.

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