Derivative Financial Instruments (Narrative) (Detail)	3 Months Ended	6 Months Ended
	Mar. 31, 2022 USD ($)	Jun. 30, 2022 USD ($) derivativeInstrument	Dec. 31, 2021 derivativeInstrument	Jun. 30, 2021 derivativeInstrument
Derivative Instruments, Gain (Loss) [Line Items]
Amount to be reclassified from accumulated other comprehensive income to interest expense in the next twelve months		$ 21,400,000
Net derivative liability position, aggregate fair value		$ 100,000
Mortgage banking derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Number of derivative instruments held | derivativeInstrument		0	0	0
Not designated as hedging instrument | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		$ 0
Not designated as hedging instrument | Interest rate contract terminated
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		1,000,000,000
Not designated as hedging instrument | Interest rate contract, qualified borrowers
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		9,700,000,000
Not designated as hedging instrument | Forward commitments to sell mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		675,500,000
Not designated as hedging instrument | Interest rate lock commitments
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		323,200,000
Not designated as hedging instrument | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		$ 18,700,000
Not designated as hedging instrument | Covered call options
Derivative Instruments, Gain (Loss) [Line Items]
Number of derivative instruments held | derivativeInstrument		0	0	0
Interest rate derivatives designated as Cash Flow Hedges | Designated as hedging instrument | Interest Rate Collar
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | derivativeInstrument		1
Interest rate derivatives designated as Cash Flow Hedges | Designated as hedging instrument | Interest Rate Swap Terminated, Original Swap Maturing March 2023
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	$ 1,000,000,000
Derivative term	5 years
Fair value of derivative contracts	$ 66,500,000	$ 3,700,000
Interest rate derivatives designated as Cash Flow Hedges | Designated as hedging instrument | Interest Rate Swap Terminated, Original Swap Maturing April 2024
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount		500,000,000
Fair value of derivative contracts		$ 10,700,000
Interest rate derivatives designated as Fair Value Hedges | Designated as hedging instrument | Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | derivativeInstrument		13
Notional amount		$ 208,900,000
Interest rate derivatives designated as Fair Value Hedges | Designated as hedging instrument | Interest Rate Swap, Term Beginning Subsequent To Period End
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | derivativeInstrument		1
Notional amount		$ 73,900,000