Loans - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair value adjustment of derivative	$ 3,000	$ 2,700
Residential mortgage loan	2,512,852	2,556,167
Asset Pledged as Collateral without Right [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential mortgage loan	11,400	12,100
Asset Pledged as Collateral without Right [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential mortgage loan	358,800	158,900
Asset Pledged as Collateral without Right [Member] | Multi-family Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential mortgage loan	46,200
Asset Pledged as Collateral without Right [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential mortgage loan	$ 194,300	$ 210,900