Investment Securities (Tables)

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Schedule of available-for-sale securities reconciliation

The following table presents amortized cost, gross unrealized gains and losses, and fair values of securities available-for-sale as of the dates indicated:

	June 30, 2021								December 31, 2020
			Gross		Gross						Gross		Gross
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
Security Type	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
	(In thousands)
Municipal securities	$	1,735,937	$	83,607	$	(2,045)	$	1,817,499	$	1,438,004	$	93,631	$	(18)	$	1,531,617
Agency commercial MBS	1,203,537		56,261		(2,170)		1,257,628		1,207,676		74,238		(37)		1,281,877
Agency residential CMOs	1,108,587		36,736		(2,925)		1,142,398		1,172,166		47,994		(280)		1,219,880
U.S. Treasury securities	873,480		4,266		(593)		877,153		4,989		313		—		5,302
Agency residential MBS	544,762		11,208		(3,559)		552,411		329,488		12,483		(897)		341,074
Corporate debt securities	496,749		12,457		(498)		508,708		308,803		3,490		(404)		311,889
Collateralized loan obligations	382,935		260		(1,152)		382,043		136,777		23		(924)		135,876
Private label commercial MBS	375,184		3,126		(75)		378,235		81,878		1,089		(10)		82,957
Asset-backed securities	148,965		961		(343)		149,583		166,861		445		(760)		166,546
Private label residential CMOs	93,011		4,141		(230)		96,922		110,891		6,076		(21)		116,946
SBA securities	34,388		1,659		(19)		36,028		39,437		2,217		(27)		41,627
Total	$	6,997,535	$	214,682	$	(13,609)	$	7,198,608	$	4,996,970	$	241,999	$	(3,378)	$	5,235,591

Schedule of realized gains and losses on securities available-for-sale

The following table presents the amortized cost of securities sold with related gross realized gains, gross realized losses, and net realized gains for the years indicated:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
Sales of Securities Available-for-Sale	2021		2020		2021		2020
	(In thousands)
Amortized cost of securities sold	$	—	$	122,334	$	44,551	$	137,100
Gross realized gains	$	—	$	7,747	$	101	$	7,929
Gross realized losses	—		(32)		—		(32)
Net realized gains	$	—	$	7,715	$	101	$	7,897

Unrealized losses on investment securities

The following tables present the gross unrealized losses and fair values of securities available-for-sale that were in unrealized loss positions as of the dates indicated:

	June 30, 2021
	Less Than 12 Months				12 Months or More				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
Security Type	Value		Losses		Value		Losses		Value		Losses
	(In thousands)
Municipal securities	$	203,261	$	(2,045)	$	—	$	—	$	203,261	$	(2,045)
Agency commercial MBS	126,899		(2,170)		—		—		126,899		(2,170)
Agency residential CMOs	125,880		(2,925)		—		—		125,880		(2,925)
U.S. Treasury securities	374,149		(593)		—		—		374,149		(593)
Agency residential MBS	303,546		(3,551)		687		(8)		304,233		(3,559)
Corporate debt securities	57,401		(498)		—		—		57,401		(498)
Collateralized loan obligations	201,170		(995)		43,854		(157)		245,024		(1,152)
Private label commercial MBS	13,476		(67)		2,196		(8)		15,672		(75)
Asset-backed securities	—		—		16,381		(343)		16,381		(343)
Private label residential CMOs	24,957		(216)		624		(14)		25,581		(230)
SBA securities	—		—		1,914		(19)		1,914		(19)
Total	$	1,430,739	$	(13,060)	$	65,656	$	(549)	$	1,496,395	$	(13,609)

	December 31, 2020
	Less Than 12 Months				12 Months or More				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
Security Type	Value		Losses		Value		Losses		Value		Losses
	(In thousands)
Municipal securities	$	5,919	$	(18)	$	—	$	—	$	5,919	$	(18)
Agency commercial MBS	58,408		(37)		—		—		58,408		(37)
Agency residential CMOs	97,863		(280)		—		—		97,863		(280)
Agency residential MBS	90,722		(897)		—		—		90,722		(897)
Asset-backed securities	14,636		(53)		61,031		(707)		75,667		(760)
Corporate debt securities	87,596		(404)		—		—		87,596		(404)
Collateralized loan obligations	96,442		(729)		28,972		(195)		125,414		(924)
Private label commercial MBS	3,058		(10)		—		—		3,058		(10)
Private label residential CMOs	788		(19)		74		(2)		862		(21)
SBA securities	2,127		(27)		—		—		2,127		(27)
Total	$	457,559	$	(2,474)	$	90,077	$	(904)	$	547,636	$	(3,378)

Investments classified by contractual maturity date

The following table presents the contractual maturities of our securities available-for-sale portfolio based on amortized cost and carrying value as of the date indicated:

	June 30, 2021
	Amortized		Fair
Maturities	Cost		Value
	(In thousands)
Due in one year or less	$	27,259	$	27,267
Due after one year through five years	579,444		608,063
Due after five years through ten years	2,657,145		2,713,777
Due after ten years	3,733,687		3,849,501
Total securities available-for-sale	$	6,997,535	$	7,198,608

Investment income

The following table presents the composition of our interest income on investment securities for the periods indicated:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
	(In thousands)
Taxable interest	$	25,206	$	19,836	$	47,176	$	41,622
Non-taxable interest	8,493		5,612		16,571		10,841
Dividend income	255		590		472		1,021
Total interest income on investment securities	$	33,954	$	26,038	$	64,219	$	53,484