Loans Receivable and Allowance for Loan Losses - Schedule of Allowance for Loan Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 88,023	$ 80,740	$ 101,466
Provision charge (benefit) for credit losses on loans	27,900	8,400	(24,300)
Recoveries of loans previously charged off	2,292	5,431	9,030
Loans charged off	(10,421)	(6,548)	(5,456)
Balance at end of period	107,200	88,023	80,740
Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(594)	0	0
Balance at end of period		(594)	0
Mortgage Portfolio Segment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	58,218	52,104
Provision charge (benefit) for credit losses on loans	16,877	11,087
Recoveries of loans previously charged off	546	585
Loans charged off	(1,724)	(5,558)
Balance at end of period	73,407	58,218	52,104
Mortgage Portfolio Segment | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(510)
Balance at end of period		(510)
Commercial loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	27,413	26,343
Provision charge (benefit) for credit losses on loans	11,159	(2,489)
Recoveries of loans previously charged off	1,309	4,192
Loans charged off	(8,363)	(633)
Balance at end of period	31,475	27,413	26,343
Commercial loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(43)
Balance at end of period		(43)
Consumer loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	2,392	2,293
Provision charge (benefit) for credit losses on loans	(136)	(198)
Recoveries of loans previously charged off	437	654
Loans charged off	(334)	(357)
Balance at end of period	2,318	2,392	$ 2,293
Consumer loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ (41)
Balance at end of period		$ (41)