INVESTMENT AND MORTGAGE-BACKED SECURITIES (Tables)

12 Months Ended

Dec. 31, 2021

INVESTMENT AND MORTGAGE-BACKED SECURITIES

Major Categories of Securities Owned by Entity

	December 31, 2021
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
(In thousands)	Cost		Gains		Losses		Value
Securities available-for-sale:
Agency notes	$	82,476	$	—	$	(2,222)	$	80,254
Treasury securities		247,916		—		(3,147)		244,769
Corporate securities		148,430		4,354		(754)		152,030
Pass-through mortgage-backed securities ("MBS") issued by government sponsored entities ("GSEs")		528,749		4,271		(6,566)		526,454
Agency collateralized mortgage obligations ("CMOs")		527,348		2,705		(8,795)		521,258
State and municipal obligations		39,175		73		(302)		38,946
Total securities available-for-sale	$	1,574,094	$	11,403	$	(21,786)	$	1,563,711
	December 31, 2021
			Gross		Gross
	Amortized		Unrecognized		Unrecognized		Fair
(In thousands)	Cost		Gains		Losses		Value
Securities held-to-maturity:
Pass-through MBS issued by GSEs	$	118,382	$	59	$	(1,141)	$	117,300
Agency CMOs		60,927		—		(873)		60,054
Total securities held-to-maturity	$	179,309	$	59	$	(2,014)	$	177,354

	December 31, 2020
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
(In thousands)	Cost		Gains		Losses		Value
Securities available-for-sale:
Agency notes	$	47,500	$	12	$	(91)	$	47,421
Corporate securities		62,021		2,440		—		64,461
Pass-through MBS issued by GSEs		135,842		7,672		(31)		143,483
Agency CMOs		274,898		8,674		(76)		283,496
Total securities available-for-sale	$	520,261	$	18,798	$	(198)	$	538,861

Schedule of amortized cost and fair value of debt securities

	December 31, 2021
	Amortized		Fair
(In thousands)	Cost		Value
Available-for-sale
Within one year	$	852	$	858
One to five years		281,148		277,877
Five to ten years		222,851		224,137
Beyond ten years		13,145		13,127
Pass-through MBS issued by GSEs and agency CMO		1,056,098		1,047,712
Total	$	1,574,094	$	1,563,711
Held-to-maturity
Pass-through MBS issued by GSEs and agency CMO	$	179,309	$	177,354
Total	$	179,309	$	177,354

Summary of Sale of Available-for-sale Securities

	Year Ended December 31,
(In thousands)	2021		2020		2019
Securities available-for-sale
Proceeds	$	138,077	$	94,252	$	148,857
Gross gains		1,327		4,592		551
Tax expense on gains		421		1,444		175
Gross losses		120		—		520
Tax benefit on losses		38		—		166

Sales of Marketable Equity Securities

	Year Ended December 31,
(In thousands)	2021		2020		2019
Proceeds:
Marketable equity securities	$	6,101	$	546	$	570

Gross Unrealized Losses and Fair Value of Investment Securities by Investment Category and Length of Time in a Continuous Unrealized Loss Position

	December 31, 2021
	Less than 12				12 Consecutive
	Consecutive Months				Months or Longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(In thousands)	Value		Losses		Value		Losses		Value		Losses
Securities available-for-sale:
Agency notes	$	58,607	$	1,369	$	21,647	$	853	$	80,254	$	2,222
Treasury securities		244,769		3,147		—		—		244,769		3,147
Corporate securities		37,620		754		—		—		37,620		754
Pass-through MBS issued by GSEs		422,634		6,333		4,748		233		427,382		6,566
Agency CMOs		349,879		8,672		3,182		123		353,061		8,795
State and municipal obligations		18,887		302		—		—		18,887		302
Securities held-to-maturity
Pass-through MBS issued by GSEs	$	97,328	$	1,141	$	—	$	—	$	97,328	$	1,141
Agency CMOs		60,054		873		—		—		60,054		873

	December 31, 2020
	Less than 12				12 Consecutive
	Consecutive Months				Months or Longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(In thousands)	Value		Losses		Value		Losses		Value		Losses
Securities available-for-sale:
Agency notes	$	22,409	$	91	$	—	$	—	$	22,409	$	91
Pass-through MBS issued by GSEs		5,007		31		—		—		5,007		31
Agency CMOs		6,563		30		4,954		46		11,517		76