Derivatives - Derivatives Associated With Interest Rate Risk Management Activities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 3,395,932	$ 2,697,522
Assets	232,886	65,768
Liabilities	1,509	6,858
Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,395,932	2,697,522
Assets	8,822	2,583
Liabilities	16,735	3,994
Customer Interest Rate Contracts Hedging \| Hedging Instruments And Hedged Items \| Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,433,278	3,044,067
Assets	282,434	90,394
Liabilities	503	3,515
Customer Interest Rate Contracts Hedging \| Hedging Instruments And Hedged Items \| Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,433,278	3,044,067
Assets	5,750	3,537
Liabilities	23,066	9,735
Debt Hedging \| Hedging Instruments And Hedged Items \| Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Notional	500,000	500,000
Assets	61
Liabilities		69
Debt Hedging \| Hedging Instruments And Hedged Items \| Term Borrowings, Par
Derivative Instruments, Gain (Loss) [Line Items]
Term borrowings	500,000	500,000
Debt Hedging \| Hedging Instruments And Hedged Items \| Term Borrowings, Cumulative Fair Value Hedging Adjustments
Derivative Instruments, Gain (Loss) [Line Items]
Term borrowings	2,862	(1,604)
Debt Hedging \| Hedging Instruments And Hedged Items \| Term Borrowings, Unamortized Premium (Discount) and Issuance Costs
Derivative Instruments, Gain (Loss) [Line Items]
Term borrowings	(519)	(740)
Debt Hedging \| Hedging Instruments And Hedged Items \| Term Borrowings
Derivative Instruments, Gain (Loss) [Line Items]
Term borrowings	$ 502,343	$ 497,656

Amount of hedged item in hedging relationship. Excludes hedged asset or liability.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

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=109980867&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=109980867&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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- Definition

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.

+ Details

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