Debt securities available-for-sale (Tables)

12 Months Ended

Dec. 31, 2020

Investments [Abstract]

Debt Securities, Available-For-Sale

		At December 31, 2020
				Gross		Gross				Weighted
		Amortized		unrealized		unrealized		Fair		average
(In thousands)		cost		gains		losses		value		yield
U.S. Treasury securities
	Within 1 year	$	4,900,055	$	16,479	$	-	$	4,916,534	0.69	%
	After 1 to 5 years		5,007,223		259,399		-		5,266,622	2.05
	After 5 to 10 years		567,367		37,517		-		604,884	1.68
Total U.S. Treasury securities			10,474,645		313,395		-		10,788,040	1.40
Obligations of U.S. Government sponsored entities
	Within 1 year		59,993		101		-		60,094	1.46
	After 1 to 5 years		90		-		-		90	5.64
Total obligations of U.S. Government sponsored entities			60,083		101		-		60,184	1.47
Collateralized mortgage obligations - federal agencies
	After 1 to 5 years		1,388		14		-		1,402	2.97
	After 5 to 10 years		61,229		1,050		-		62,279	1.56
	After 10 years		318,292		10,202		43		328,451	2.04
Total collateralized mortgage obligations - federal agencies			380,909		11,266		43		392,132	1.97
Mortgage-backed securities
	Within 1 year		5,616		56		-		5,672	2.83
	After 1 to 5 years		50,393		1,735		-		52,128	2.35
	After 5 to 10 years		454,880		20,022		6		474,896	1.91
	After 10 years		9,608,860		180,844		1,839		9,787,865	1.94
Total mortgage-backed securities			10,119,749		202,657		1,845		10,320,561	1.94
Other
	After 1 to 5 years		224		11		-		235	3.62
Total other			224		11		-		235	3.62
Total debt securities available-for-sale[1]		$	21,035,610	$	527,430	$	1,888	$	21,561,152	1.66	%
[1]	Includes $18.2 billion pledged to secure government and trust deposits, assets sold under agreements to repurchase, credit facilities and loan servicing agreements that the secured parties are not permitted to sell or repledge the collateral, of which $16.9 billion serve as collateral for public funds.

		At December 31, 2019
				Gross		Gross				Weighted
		Amortized		unrealized		unrealized		Fair		average
(In thousands)		cost		gains		losses		value		yield
U.S. Treasury securities
	Within 1 year	$	5,071,201	$	3,262	$	567	$	5,073,896	1.58	%
	After 1 to 5 years		5,137,804		75,597		3,435		5,209,966	2.19
	After 5 to 10 years		1,778,568		429		6,604		1,772,393	1.70
Total U.S. Treasury securities			11,987,573		79,288		10,606		12,056,255	1.86
Obligations of U.S. Government sponsored entities
	Within 1 year		62,492		2		21		62,473	1.45
	After 1 to 5 years		60,021		-		90		59,931	1.48
Total obligations of U.S. Government sponsored entities			122,513		2		111		122,404	1.47
Obligations of Puerto Rico, States and political subdivisions
	Within 1 year		6,975		-		-		6,975	-
Total obligations of Puerto Rico, States and political subdivisions			6,975		-		-		6,975	-
Collateralized mortgage obligations - federal agencies
	Within 1 year		236		-		-		236	1.83
	After 1 to 5 years		350		1		-		351	2.16
	After 5 to 10 years		85,079		31		1,180		83,930	1.63
	After 10 years		504,391		3,640		6,373		501,658	2.08
Total collateralized mortgage obligations - federal agencies			590,056		3,672		7,553		586,175	2.02
Mortgage-backed securities
	Within 1 year		16		-		-		16	2.13
	After 1 to 5 years		36,717		852		1		37,568	3.38
	After 5 to 10 years		350,373		1,958		1,303		351,028	2.02
	After 10 years		4,447,561		60,384		20,243		4,487,702	2.60
Total mortgage-backed securities			4,834,667		63,194		21,547		4,876,314	2.57
Other
	After 1 to 5 years		341		9		-		350	3.62
Total other			341		9		-		350	3.62
Total debt securities available-for-sale[1]		$	17,542,125	$	146,165	$	39,817	$	17,648,473	2.05	%
[1]	Includes $12.2 billion pledged to secure government and trust deposits, assets sold under agreements to repurchase, credit facilities and loan servicing agreements that the secured parties are not permitted to sell or repledge the collateral, of which $10.9 billion serve as collateral for public funds.

Schedule Of Aggregate Amortized Cost And Fair Value Of Afs By Contractual Maturity

(In thousands)		Amortized cost		Fair value
Within 1 year	$	4,965,664	$	4,982,300
After 1 to 5 years		5,059,318		5,320,477
After 5 to 10 years		1,083,476		1,142,059
After 10 years		9,927,152		10,116,316
Total debt securities available-for-sale	$	21,035,610	$	21,561,152

Schedule Of Realized Gain Loss

(In thousands)		2020		2019		2018
Gross realized gains	$	41	$	-	$	-
Gross realized losses		-		(20)		-
Net realized gains (losses) on sale of debt securities available-for-sale	$	41	$	(20)	$	-

Debt Securities Available For Sale Unrealized Loss Position Fair Value

	At December 31, 2020
	Less than 12 months				12 months or more				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
(In thousands)	value		losses		value		losses		value		losses
Collateralized mortgage obligations - federal agencies	$	4,029	$	43	$	-	$	-	$	4,029	$	43
Mortgage-backed securities		886,432		1,834		555		11		886,987		1,845
Total debt securities available-for-sale in an unrealized loss position	$	890,461	$	1,877	$	555	$	11	$	891,016	$	1,888

	At December 31, 2019
	Less than 12 months				12 months or more				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
(In thousands)	value		losses		value		losses		value		losses
U.S. Treasury securities	$	2,439,114	$	9,798	$	452,784	$	808	$	2,891,898	$	10,606
Obligations of U.S. Government sponsored entities		9,973		4		99,846		107		109,819		111
Collateralized mortgage obligations - federal agencies		114,603		537		310,315		7,016		424,918		7,553
Mortgage-backed securities		179,312		693		1,784,414		20,854		1,963,726		21,547
Total debt securities available-for-sale in an unrealized loss position	$	2,743,002	$	11,032	$	2,647,359	$	28,785	$	5,390,361	$	39,817

Schedule Of Securities Aggregate Amortized Cost Exceed 10 Of Stockholders Equity

		2020				2019
(In thousands)	Amortized cost		Fair value		Amortized cost		Fair value
FNMA	$	2,242,121	$	2,338,897	$	3,113,373	$	3,129,538
Freddie Mac		3,616,238		3,675,679		1,623,116		1,638,796