Investment Securities (Tables)

12 Months Ended

Dec. 31, 2025

Investments, Debt and Equity Securities [Abstract]

Schedule of Investment Securities Available-for-sale

The following tables set forth investment securities available-for-sale at the dates indicated:

	At December 31, 2025
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(In Thousands)
Investment securities available-for-sale:
GSE debentures	$	185,449	$	512	$	12,284	$	173,677
GSE CMOs	500,446		2,784		6,660		496,570
GSE MBSs	334,476		3,009		11,740		325,745
Municipal obligations	231,924		8,305		13		240,216
Corporate debt obligations	39,209		863		49		40,023
U.S. Treasury bonds	424,214		1,727		13,904		412,037
Foreign government obligations	500		—		—		500
Total investment securities available-for-sale	$	1,716,218	$	17,200	$	44,650	$	1,688,768

	At December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(In Thousands)
Investment securities available-for-sale:
GSE debentures	$	195,099	$	225	$	19,030	$	176,294
GSE CMOs	62,567		4		7,028		55,543
GSE MBSs	166,843		63		18,621		148,285
Municipal obligations	20,526		19		291		20,254
Corporate debt obligations	12,140		225		78		12,287
U.S. Treasury bonds	506,714		331		25,173		481,872
Foreign government obligations	500		—		1		499
Total investment securities available-for-sale	$	964,389	$	867	$	70,222	$	895,034

Schedule of Investment Securities in a Continuous Unrealized Loss Position

Investment securities as of December 31, 2025 and 2024 that have been in a continuous unrealized loss position for less than twelve months or twelve months or longer are as follows:

	At December 31, 2025
	Less than Twelve Months				Twelve Months or Longer				Total
	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
	(In Thousands)
Investment securities available-for-sale:
GSE debentures	$	32	$	1	$	103,884	$	12,283	$	103,916	$	12,284
GSE CMOs	68,184		460		45,145		6,200		113,329		6,660
GSE MBSs	79		1		114,594		11,739		114,673		11,740
Municipal obligations	9,721		11		391		2		10,112		13
Corporate debt obligations	4,943		41		2,666		8		7,609		49
U.S. Treasury bonds	—		—		203,283		13,904		203,283		13,904
Foreign government obligations	—		—		—		—		—		—
Temporarily impaired investment securities available-for-sale	82,959		514		469,963		44,136		552,922		44,650
Total temporarily impaired investment securities	$	82,959	$	514	$	469,963	$	44,136	$	552,922	$	44,650

	At December 31, 2024
	Less than Twelve Months				Twelve Months or Longer				Total
	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
	(In Thousands)
Investment securities available-for-sale:
GSE debentures	$	30,753	$	281	$	107,750	$	18,749	$	138,503	$	19,030
GSE CMOs	4,664		107		50,334		6,921		54,998		7,028
GSE MBSs	11,128		596		131,481		18,025		142,609		18,621
Municipal obligations	3,616		74		3,568		217		7,184		291
Corporate debt obligations	—		—		2,550		78		2,550		78
U.S. Treasury bonds	67,290		285		291,641		24,888		358,931		25,173
Foreign government obligations	—		—		499		1		499		1
Temporarily impaired investment securities available-for-sale	117,451		1,343		587,823		68,879		705,274		70,222
Total temporarily impaired investment securities	$	117,451	$	1,343	$	587,823	$	68,879	$	705,274	$	70,222

Schedule of Maturities of the Investments in Debt Securities

The final stated maturities of the debt securities are as follows for the periods indicated:

	At December 31,
	2025					2024
	Amortized Cost		Estimated Fair Value		Weighted Average Rate	Amortized Cost		Estimated Fair Value		Weighted Average Rate
	(Dollars in Thousands)
Investment securities available-for-sale:
Within 1 year	$	145,787	$	146,092	3.89%	$	103,337	$	102,457	3.22%
After 1 year through 5 years	472,284		454,138		2.76%	449,289		434,608		3.32%
After 5 years through 10 years	246,784		242,931		3.56%	207,980		180,370		1.77%
Over 10 years	851,363		845,607		4.18%	203,783		177,599		3.13%
	$	1,716,218	$	1,688,768	3.69%	$	964,389	$	895,034	2.96%