Derivative Financial Instruments - Additional information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Derivative [Line Items]
Maximum length of time hedged in cash flow hedge			4 years
Credit exposure to settled variation margin in excess of customer related interest rate swap	$ 1,000,000		$ 1,000,000		$ 0
Notional Amount	2,400,000,000		2,400,000,000		2,400,000,000
Derivative, gain (loss) on derivative, net (less than during the three months ended June 30, 2022 and the six months ended June 30, 2023)	(100,000)	$ (100,000)	(100,000)	$ (200,000)
Derivative asset (less than as of both June 30, 2023 and December 31, 2022)	22,434,000		22,434,000		23,861,000
Loan Origination Commitments
Derivative [Line Items]
Notional Amount	8,500,000		8,500,000		8,300,000
Derivative asset (less than as of both June 30, 2023 and December 31, 2022)	100,000		100,000		100,000
Forward Contracts
Derivative [Line Items]
Notional Amount	6,600,000		6,600,000		10,000,000
Non Cleared Derivative Transactions | Customer Related Interest Rate Swap Derivatives
Derivative [Line Items]
Fair value of interest rate swap liabilities that are net in a net liability position	0		0		0
Cash and Cash Equivalents | Non Cleared Derivative Transactions | Customer Related Interest Rate Swap Derivatives
Derivative [Line Items]
Additional collateral posted	1,000,000		1,000,000		1,000,000
Restricted Assets | Cash and Cash Equivalents | Cleared Derivative Transaction
Derivative [Line Items]
Additional collateral posted	84,100,000		84,100,000		$ 84,100,000
Interest Income | Active Cash Flow Hedges
Derivative [Line Items]
Interest rate swap cash flow hedges amount expected to reclassified from other comprehensive income to income statement in the next twelve months	$ 52,300,000		$ 52,300,000