Derivative Instruments And Hedging Activities - Narrative (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) Swap derivative	Dec. 31, 2018 USD ($) derivative Swap
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from AOCI to interest expense	$ 6,200
Period for hedging exposure to the variability in future cash flows for forecasted transactions	54 months
Derivative, net liability position, fair value	$ 46,400
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Cash collateral pledged	$ 45,727	$ 702
Not Designated as Hedging Instrument | Minimum
Derivative Instruments, Gain (Loss) [Line Items]
Derivative expiration period	30 days
Not Designated as Hedging Instrument | Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Derivative expiration period	60 days
Not Designated as Hedging Instrument | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate swaps | Swap	140	98
Derivative notional amount	$ 1,400,000	$ 1,000,000
Not Designated as Hedging Instrument | Interest rate caps
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate swaps | Swap	4	0
Derivative notional amount	$ 78,600
Not Designated as Hedging Instrument | Residential mortgage loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	4,500	$ 3,600
Not Designated as Hedging Instrument | Credit contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 167,100	$ 94,900
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate swaps | derivative	4	6
Derivative notional amount	$ 725,000	$ 750,000