Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Notional amounts	$ 1,106,000,000		$ 1,106,000,000		$ 665,500,000
Percentage of periodic changes in fair value qualifies for hedge accounting treatment	100.00%		100.00%
Reclassified interest income (expense)	$ 145,573,000	$ 153,096,000	$ 435,015,000	$ 455,374,000
Amount Reclassified from AOCI | Interest Income
Derivative [Line Items]
Reclassified interest income (expense)			7,100,000
Amount Reclassified from AOCI | interest expense
Derivative [Line Items]
Reclassified interest income (expense)			1,700,000
Fixed Interest Swap
Derivative [Line Items]
Notional amounts	380,500,000		380,500,000		130,500,000
Variable Interest Rate Swap
Derivative [Line Items]
Notional amounts	325,000,000.0		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
Interest Rate Lock Commitments
Derivative [Line Items]
Notional amounts	233,300,000		233,300,000		65,700,000
Forward Commitments
Derivative [Line Items]
Notional amounts	291,600,000		291,600,000		101,600,000
Customer Derivative Instrument
Derivative [Line Items]
Notional amounts	1,792,000,000		1,792,000,000		1,298,000,000
Offsetting Counter Party Derivative Instrument
Derivative [Line Items]
Notional amounts	1,792,000,000		1,792,000,000		1,298,000,000
Foreign Currency Forward Contract | Foreign currency contracts
Derivative [Line Items]
Notional amounts	$ 9,300,000		$ 9,300,000		$ 8,200,000