Derivatives - Derivatives Associated with Fixed Income Trading Activities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 3,847,085	$ 2,697,522
Assets	240,218	65,768
Liabilities	2,444	6,858
Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,847,085	2,697,522
Assets	2,317	2,583
Liabilities	16,828	3,994
Option contracts purchased \| Long
Derivative Instruments, Gain (Loss) [Line Items]
Notional		40,000
Assets		131
Liabilities		0
Forwards and futures purchased
Derivative Instruments, Gain (Loss) [Line Items]
Notional	15,069,709	9,217,350
Assets	41,553	17,029
Liabilities	3,456	3,187
Forwards and futures sold
Derivative Instruments, Gain (Loss) [Line Items]
Notional	15,596,324	9,403,112
Assets	5,788	3,611
Liabilities	$ 39,018	$ 16,620

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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

No definition available.

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Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

No definition available.

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