Percentage of periodic changes in fair value qualifies for hedge accounting.

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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

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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

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-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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The net amount of operating interest income (expense).

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-Section S99
-Paragraph 1
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Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional amounts	$ 1,452,000,000				$ 665,500,000				$ 1,452,000,000	$ 665,500,000
Percentage of periodic changes in fair value qualifies for hedge accounting treatment	100.00%								100.00%
Reclassified interest income (expense)	$ 161,079,000	$ 145,573,000	$ 145,671,000	$ 143,771,000	148,899,000	$ 153,096,000	$ 155,230,000	$ 147,048,000	$ 596,094,000	604,273,000	$ 537,602,000
Amount Reclassified from AOCI \| Interest Income
Derivative [Line Items]
Reclassified interest income (expense)									6,100,000
Amount Reclassified from AOCI \| interest expense
Derivative [Line Items]
Reclassified interest income (expense)									(1,800,000)
Fixed Interest Swap
Derivative [Line Items]
Notional amounts	379,000,000.0				130,500,000				379,000,000.0	130,500,000
Variable Interest Rate Swap, Available-for-sale Investment Securities
Derivative [Line Items]
Notional amounts	347,500,000								347,500,000
Variable Interest Rate Swap, Borrowings
Derivative [Line Items]
Notional amounts	325,000,000.0				25,000,000.0				325,000,000.0	25,000,000.0
Variable Interest Rate Collars and Floors
Derivative [Line Items]
Notional amounts	400,000,000.0								400,000,000.0
Variable Interest Rate Collar
Derivative [Line Items]
Notional amounts					510,000,000.0					510,000,000.0
Interest Rate Lock Commitments
Derivative [Line Items]
Notional amounts	224,700,000				65,700,000				224,700,000	65,700,000
Forward Commitments
Derivative [Line Items]
Notional amounts	261,000,000.0				101,600,000				261,000,000.0	101,600,000
Offsetting Counter Party Derivative Instrument
Derivative [Line Items]
Notional amounts	2,008,000,000.000				1,298,000,000				2,008,000,000.000	1,298,000,000
Customer Derivative Instrument
Derivative [Line Items]
Notional amounts	2,008,000,000.000				1,298,000,000				2,008,000,000.000	1,298,000,000
Foreign Currency Forward Contract \| Foreign currency contracts
Derivative [Line Items]
Notional amounts	$ 9,900,000				$ 8,200,000				$ 9,900,000	$ 8,200,000