Investment Securities (Tables)

12 Months Ended

Dec. 31, 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:

	December 31,
	2021								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)
Agency residential MBS	$	2,921,993	$	8,866	$	(32,649)	$	2,898,210	$	329,488	$	12,483	$	(897)	$	341,074
Municipal securities	2,248,749		75,192		(7,973)		2,315,968		1,438,004		93,631		(18)		1,531,617
Agency commercial MBS	1,660,516		37,664		(9,213)		1,688,967		1,207,676		74,238		(37)		1,281,877
Agency residential CMOs	1,021,716		22,288		(5,870)		1,038,134		1,172,166		47,994		(280)		1,219,880
U.S. Treasury securities	973,555		1,641		(8,298)		966,898		4,989		313		—		5,302
Corporate debt securities	514,077		13,774		(757)		527,094		308,803		3,490		(404)		311,889
Private label commercial MBS	453,314		147		(3,244)		450,217		81,878		1,089		(10)		82,957
Collateralized loan obligations	385,410		396		(444)		385,362		136,777		23		(924)		135,876
Private label residential CMOs	265,851		1,857		(3,291)		264,417		110,891		6,076		(21)		116,946
Asset-backed securities	129,387		484		(324)		129,547		166,861		445		(760)		166,546
SBA securities	28,950		726		(32)		29,644		39,437		2,217		(27)		41,627
Total	$	10,603,518	$	163,035	$	(72,095)	$	10,694,458	$	4,996,970	$	241,999	$	(3,378)	$	5,235,591

Schedule of Realized Gain (Loss)

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:

	Year Ended December 31,
Sales of Securities Available-for-Sale	2021		2020		2019
	(In thousands)
Amortized cost of securities sold	$	365,733	$	160,254	$	1,559,415
Gross realized gains	$	1,680	$	13,222	$	29,584
Gross realized losses	(65)		(51)		(4,139)
Net realized gains	$	1,615	$	13,171	$	25,445

Unrealized losses on investment securities

Unrealized Losses on Securities Available-for-Sale

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:

	December 31, 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)
Agency residential MBS	$	2,502,536	$	(31,670)	$	57,329	$	(979)	$	2,559,865	$	(32,649)
Municipal securities	505,080		(6,965)		29,726		(1,008)		534,806		(7,973)
Agency commercial MBS	440,938		(5,066)		106,745		(4,147)		547,683		(9,213)
Agency residential CMOs	216,445		(3,757)		67,340		(2,113)		283,785		(5,870)
U.S. Treasury securities	628,767		(8,298)		—		—		628,767		(8,298)
Corporate debt securities	32,761		(757)		—		—		32,761		(757)
Private label commercial MBS	397,619		(3,244)		—		—		397,619		(3,244)
Collateralized loan obligations	137,619		(374)		43,730		(70)		181,349		(444)
Private label residential CMOs	201,988		(3,291)		—		—		201,988		(3,291)
Asset-backed securities	38,742		(137)		15,762		(187)		54,504		(324)
SBA securities	—		—		1,864		(31)		1,864		(32)
Total	$	5,102,495	$	(63,559)	$	322,496	$	(8,535)	$	5,424,991	$	(72,095)

	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)
Agency residential MBS	$	90,722	$	(897)	$	—	$	—	$	90,722	$	(897)
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)
Corporate debt securities	87,596		(404)		—		—		87,596		(404)
Private label commercial MBS	3,058		(10)		—		—		3,058		(10)
Collateralized loan obligations	96,442		(729)		28,972		(195)		125,414		(924)
Private label residential CMOs	788		(19)		74		(2)		862		(21)
Asset-backed securities	14,636		(53)		61,031		(707)		75,667		(760)
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 available-for-sale securities portfolio based on amortized cost and carrying value as of the date indicated.

	December 31, 2021
	Amortized		Fair
Maturity	Cost		Value
	(In thousands)
Due in one year or less	$	54,301	$	54,685
Due after one year through five years	635,456		662,377
Due after five years through ten years	3,526,824		3,544,687
Due after ten years	6,386,937		6,432,709
Total securities available-for-sale	$	10,603,518	$	10,694,458

Investment Income

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

	Year Ended December 31,
	2021		2020		2019
	(In thousands)
Taxable interest	$	118,561	$	80,426	$	85,968
Non-taxable interest	33,916		24,771		27,955
Dividend income	991		1,573		1,646
Total interest income on investment securities	$	153,468	$	106,770	$	115,569