Noninterest Income - Gains on Investment Securities, Net (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Gains on non-marketable and other equity securities, net	$ 138,575	$ 88,834	$ 69,792
Losses on sales of available-for-sale debt securities, net	(3,905)	(740)	(5,189)
Gains on investment securities, net	$ 134,670	$ 88,094	$ 64,603

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
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Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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-Paragraph 28
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-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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