The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Nominal or face amount used to calculate payment on derivative.

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The number of derivative instruments of a particular group held by the entity.

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Number of interest rate derivative instruments held by the entity at the reporting date.

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Derivative Financial Instruments (Narrative) (Detail)	9 Months Ended
Derivative Financial Instruments (Narrative) (Detail)	Sep. 30, 2020 USD ($) derivative_instruments	Dec. 31, 2019 derivative_instruments	Sep. 30, 2019 derivative_instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount to be reclassified from accumulated other comprehensive income to interest expense in the next twelve months	$ 20,200,000
Net derivative liability position, aggregate fair value	323,500,000
Interest Rate Contract \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	1,000,000,000.0
Interest Rate Contract, Qualified Borrowers \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	8,800,000,000
Forward Commitments to Sell Mortgage Loans \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	2,800,000,000
Interest Rate Lock Commitments \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	1,800,000,000
Foreign Exchange Contract \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	$ 3,100,000
Covered Call Options \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Number of derivative instruments held \| derivative_instruments	0	0	0
Mortgage banking derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Number of derivative instruments held \| derivative_instruments	0	0
Cash Flow Hedging \| Interest Rate Swap \| Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held \| derivative_instruments	27
Cash Flow Hedging \| Interest Rate Collar \| Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held \| derivative_instruments	1
Fair Value Hedging \| Interest Rate Swap \| Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held \| derivative_instruments	16
Notional amount	$ 163,100,000