Loans Receivable and Allowance for Credit Losses (Schedule of Allowance for Loan Losses by Portfolio Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 107,200	$ 88,023
Provision charge (benefit) to operations	200	6,000
Recoveries of loans previously charged-off	895	256
Loans charged-off	(1,866)	(927)
Balance at end of period	106,429	92,758
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period		(594)
Mortgage loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	73,407	58,218
Provision charge (benefit) to operations	(7,580)	6,212
Recoveries of loans previously charged-off	63	3
Loans charged-off	0	(728)
Balance at end of period	65,890	63,195
Mortgage loans | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period		(510)
Commercial loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	31,475	27,413
Provision charge (benefit) to operations	7,924	(308)
Recoveries of loans previously charged-off	687	168
Loans charged-off	(1,794)	(113)
Balance at end of period	38,292	27,117
Commercial loans | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period		(43)
Consumer loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	2,318	2,392
Provision charge (benefit) to operations	(144)	96
Recoveries of loans previously charged-off	145	85
Loans charged-off	(72)	(86)
Balance at end of period	$ 2,247	2,446
Consumer loans | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period		$ (41)