Noninterest Income - Gains and Losses on Investments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Income and Expenses [Abstract]
Total net gains on non-marketable and other equity securities	$ 189,837	$ 29,849	$ 209,595	$ 110,480
Gains (losses) on sales of available-for-sale securities, net	0	0	61,165	(3,905)
Gains on investment securities, net	$ 189,837	$ 29,849	$ 270,760	$ 106,575

Amount of realized and unrealized gain (loss) on investment.

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