This table provides detailed information about securities available for sale at June 30, 2022 and December 31, 2021 (in thousands):

June 30, 2022	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury	$	763,497	$	80	$	(12,825	)	$	750,752
U.S. Agencies		178,406		—		(3,159	)		175,247
Mortgage-backed		4,893,628		567		(407,610	)		4,486,585
State and political subdivisions		1,783,759		2,402		(123,786	)		1,662,375
Corporates		409,719		2		(25,936	)		383,785
Collateralized loan obligations		288,496		—		(8,024	)		280,472
Total	$	8,317,505	$	3,051	$	(581,340	)	$	7,739,216

December 31, 2021	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury	$	69,551	$	374	$	(751	)	$	69,174
U.S. Agencies		121,681		3,252		(1	)		124,932
Mortgage-backed		7,967,537		93,390		(95,872	)		7,965,055
State and political subdivisions		3,270,160		161,674		(9,146	)		3,422,688
Corporates		316,840		2,504		(1,498	)		317,846
Collateralized loan obligations		76,815		4		—			76,819
Total	$	11,822,584	$	261,198	$	(107,268	)	$	11,976,514

The following table presents contractual maturity information for securities available for sale at June 30, 2022 (in thousands):

	Amortized		Fair
	Cost		Value
Due in 1 year or less	$	108,437	$	108,364
Due after 1 year through 5 years		1,571,301		1,533,973
Due after 5 years through 10 years		760,248		727,509
Due after 10 years		983,891		882,785
Total		3,423,877		3,252,631
Mortgage-backed securities		4,893,628		4,486,585
Total securities available for sale	$	8,317,505	$	7,739,216

Securities may be disposed of before contractual maturities due to sales by the Company or because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

For the six months ended June 30, 2022, there were no sales of securities available for sale. For the six months ended June 30, 2021, there were $176.8 million in proceeds from sales of securities available for sale. There were no gross realized gains for the six months ended June 30, 2022. Securities transactions resulted in gross realized gains of $4.0 million for the six months ended June 30, 2021. There were no gross realized losses for either the six months ended June 30, 2022 or 2021.

There were $9.8 billion and $10.2 billion of securities pledged to secure U.S. Government deposits, other public deposits, certain trust deposits, derivative transactions, and repurchase agreements at June 30, 2022 and December 31, 2021, respectively. Of these amounts, securities with a market value of $140.7 million and $171.2 million at June 30, 2022 and December 31, 2021, respectively, were pledged at the Federal Reserve Discount Window but were unencumbered as of those dates.

Accrued interest on securities available for sale totaled $33.6 million and $45.8 million as of June 30, 2022 and December 31, 2021, respectively, and is included in the Accrued income line on the Company’s Consolidated Balance Sheets. The total amount of accrued interest is excluded from the amortized cost of available-for-sale securities presented above. Further, the Company has elected not to measure an ACL for accrued interest receivable.

The following table shows the Company’s available-for-sale investments’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at June 30, 2022 and December 31, 2021 (in thousands):

	Less than 12 months							12 months or more							Total
June 30, 2022	Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses
Description of Securities
U.S. Treasury		61	$	735,873	$	(12,825	)		—	$	—	$	—			61	$	735,873	$	(12,825	)
U.S. Agencies		29		175,248		(3,159	)		—		—		—			29		175,248		(3,159	)
Mortgage-backed		827		3,869,920		(337,668	)		31		514,883		(69,942	)		858		4,384,803		(407,610	)
State and political subdivisions		1,842		1,281,911		(109,512	)		60		54,828		(14,274	)		1,902		1,336,739		(123,786	)
Corporates		275		374,793		(25,809	)		2		3,991		(127	)		277		378,784		(25,936	)
Collateralized loan obligations		40		280,472		(8,024	)		—		—		—			40		280,472		(8,024	)
Total		3,074	$	6,718,217		(496,997	)		93		573,702		(84,343	)		3,167	$	7,291,919	$	(581,340	)

	Less than 12 months							12 months or more							Total
December 31, 2021	Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses
Description of Securities
U.S. Treasury		4	$	58,867	$	(751	)		—	$	—	$	—			4	$	58,867	$	(751	)
U.S. Agencies		1		11,149		(1	)		—		—		—			1		11,149		(1	)
Mortgage-backed		344		5,404,968		(87,301	)		13		233,295		(8,571	)		357		5,638,263		(95,872	)
State and political subdivisions		357		329,042		(6,969	)		31		44,939		(2,177	)		388		373,981		(9,146	)
Corporates		152		193,899		(1,498	)		—		—		—			152		193,899		(1,498	)
Collateralized loan obligations		—		—		—			—		—		—			—		—		—
Total		858	$	5,997,925	$	(96,520	)		44	$	278,234	$	(10,748	)		902	$	6,276,159	$	(107,268	)

The unrealized losses in the Company’s investments were caused by changes in interest rates, and not from a decline in credit of the underlying issuers. The U.S. Treasury, U.S. Agency, and GSE mortgage-backed securities are all considered to be agency-backed securities with no risk of loss as they are either explicitly or implicitly

guaranteed by the U.S. government. The changes in fair value in the agency-backed portfolios are solely driven by change in interest rates caused by changing economic conditions. The Company has no knowledge of any underlying credit issues and the cash flows underlying the debt securities have not changed and are not expected to be impacted by changes in interest rates.

For the State and political subdivision portfolio, the majority of the Company’s holdings are in general obligation bonds, which have a very low historical default rate due to issuers generally having unlimited taxing authority to service the debt. For the State and political, Corporate, and Collateralized loan obligations portfolios, the Company has a robust process for monitoring credit risk, including both pre-purchase and ongoing post-purchase credit reviews and analysis. The Company monitors credit ratings of all bond issuers in these segments and reviews available financial data, including market and sector trends.

As of June 30, 2022 and December 31, 2021, there was no ACL related to the Company’s available-for-sale securities as the decline in fair value did not result from credit issues.

The following table shows the Company’s held-to-maturity investments’ amortized cost, fair value, and gross unrealized gains and losses at June 30, 2022 and December 31, 2021, respectively (in thousands):

June 30, 2022	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Allowance for Credit Losses			Net Carrying Amount
U.S. Agencies	$	123,033	$	—	$	(1,177	)	$	121,856	$	—		$	123,033
Mortgage-backed		3,088,814		160		(212,959	)		2,876,015		—			3,088,814
State and political subdivisions		2,497,694		648		(250,762	)		2,247,580		(2,259	)		2,495,435
Total	$	5,709,541	$	808	$	(464,898	)	$	5,245,451	$	(2,259	)	$	5,707,282

December 31, 2021	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Allowance for Credit Losses			Net Carrying Amount
Mortgage-backed	$	396,134	$	14	$	(2,431	)	$	393,717	$	—		$	396,134
State and political subdivisions		1,084,282		3,346		(38,954	)		1,048,674		(1,940	)		1,082,342
Total	$	1,480,416	$	3,360	$	(41,385	)	$	1,442,391	$	(1,940	)	$	1,478,476

The following table presents contractual maturity information for securities held to maturity at June 30, 2022 (in thousands):

	Amortized Cost		Fair Value
Due in 1 year or less	$	55,797	$	55,397
Due after 1 year through 5 years		341,617		333,267
Due after 5 years through 10 years		720,150		654,860
Due after 10 years		1,503,163		1,325,912
Total		2,620,727		2,369,436
Mortgage-backed securities		3,088,814		2,876,015
Total securities held to maturity	$	5,709,541	$	5,245,451

Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

There were no sales of securities held to maturity during the six months ended June 30, 2022 or 2021.

During the first quarter of 2022, securities with an amortized cost of $3.0 billion and a fair value of $2.9 billion were transferred from the available-for-sale classification to the held-to-maturity classification as the Company has the positive intent and ability to hold these securities to maturity. Additionally, during the second quarter of 2022, securities with an amortized cost of $831.3 million and a fair value of $736.5 million were transferred from the available-for-sale classification to the held-to-maturity classification. The transfers of securities were made at fair value at the time of transfer. The unrealized holding loss at the time of transfer is retained in AOCI and will be amortized over the remaining life of the securities, offsetting the related amortization of discount or premium on the transferred securities. No gains or losses were recognized at the time of the transfers. The amortized cost balance of securities held to maturity in the tables above includes a net unamortized unrealized loss of $238.1 million at June 30, 2022.

Accrued interest on securities held to maturity totaled $21.6 million and $5.3 million at June 30, 2022 and December 31, 2021, respectively, and is included in the Accrued income line on the Company’s Consolidated Balance Sheets. The total amount of accrued interest is excluded from the amortized cost of held-to-maturity securities presented above. Further, the Company has elected not to measure an ACL for accrued interest receivable.

The following table shows the Company’s held-to-maturity investments’ gross unrealized losses and fair value, aggregated by length of time that individual securities have been in a continuous unrealized loss position, at June 30, 2022 and December 31, 2021, respectively (in thousands):

	Less than 12 months							12 months or more							Total
June 30, 2022	Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses
U.S. Agencies		11	$	121,856	$	(1,177	)		—	$	—	$	—			11	$	121,856	$	(1,177	)
Mortgage-backed		252		2,843,277		(212,959	)		—		—		—			252		2,843,277		(212,959	)
State and political subdivisions		1,321		1,676,062		(200,246	)		44		357,949		(50,516	)		1,365		2,034,011		(250,762	)
Total		1,584	$	4,641,195	$	(414,382	)		44	$	357,949	$	(50,516	)		1,628	$	4,999,144	$	(464,898	)

	Less than 12 months							12 months or more							Total
December 31, 2021	Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses			Count		Fair Value		Unrealized Losses
Mortgage-backed		12	$	317,887	$	(2,431	)		—	$	—	$	—			12	$	317,887	$	(2,431	)
State and political subdivisions		58		585,153		(12,494	)		28		217,579		(26,460	)		86		802,732		(38,954	)
Total		70	$	903,040	$	(14,925	)		28	$	217,579	$	(26,460	)		98	$	1,120,619	$	(41,385	)

The unrealized losses in the Company’s held-to-maturity portfolio were caused by changes in the interest rate environment. The U.S. Agency and GSE mortgage-backed securities are considered to be agency-backed securities with no risk of loss as they are either explicitly or implicitly guaranteed by the U.S. government. Therefore, the Company’s expected lifetime loss for these portfolios is zero and there is no ACL recorded for this portfolio. The Company has no knowledge of any underlying credit issues and the cash flows underlying the debt securities have not changed and are not expected to be impacted by changes in interest rates.

For the State and political subdivision portfolio, the Company’s holdings are in general obligation bonds as well as private placement bonds, which have very low historical default rates due to issuers generally having unlimited taxing authority to service the debt. The Company has a robust process for monitoring credit risk, including both pre-purchase and ongoing post-purchase credit reviews and analysis. The Company monitors credit ratings of all bond issuers in these segments and reviews available financial data, including market and sector trends. The underlying bonds are evaluated for credit losses in conjunction with management’s estimate of the ACL based on credit rating.

The following tables show the amortized cost basis by credit rating of the Company’s held-to-maturity investments at June 30, 2022 and December 31, 2021 (in thousands):

	Amortized Cost Basis by Credit Rating - HTM Debt Securities
June 30, 2022	AAA		AA		A		BBB		BB		CCC-C		Total
State and political subdivisions:
Competitive	$	—	$	—	$	392,343	$	628,494	$	18,975	$	789	$	1,040,601
Utilities and general obligation		576,670		769,033		84,104		26,722		564		—		1,457,093
Total state and political subdivisions	$	576,670	$	769,033	$	476,447	$	655,216	$	19,539	$	789	$	2,497,694

	Amortized Cost Basis by Credit Rating - HTM Debt Securities
December 31, 2021	A		BBB		BB		CCC-C		Total
State and political subdivisions:
Competitive	$	372,696	$	605,104	$	20,678	$	870	$	999,348
Utilities		55,096		29,838		—		—		84,934
Total state and political subdivisions	$	427,792	$	634,942	$	20,678	$	870	$	1,084,282

Competitive held-to-maturity securities include not-for-profit enterprises that provide public functions such as housing, higher education or healthcare, but do so in a competitive environment. It also includes project financings that can have relatively high enterprise risk, such as deals backed by revenues from sports or convention facilities or start-up transportation ventures.

Utilities and general obligation are public enterprises providing essential services with a monopoly or near-monopoly over the service area. This includes environmental utilities (water, sewer, solid waste), power utilities (electric distribution and generation, gas), and transportation utilities (airports, parking, toll roads, mass transit, ports).

The following table presents the aging of past due held-to-maturity securities at December 31, 2021 (in thousands):

December 31, 2021	30-89 Days Past Due and Accruing		Greater than 90 Days Past Due and Accruing		Non- Accrual		Total Past Due		Current		Total
State and political subdivisions:
Competitive	$	7,795	$	—	$	—	$	7,795	$	991,553	$	999,348
Utilities		—		—		—		—		84,934		84,934
Total state and political subdivisions	$	7,795	$	—	$	—	$	7,795	$	1,076,487	$	1,084,282

There were net unrealized gains on trading securities of $26 thousand and $1 thousand at June 30, 2022 and 2021, respectively. Net unrealized gains and losses are included in trading and investment banking income on the

Company’s Consolidated Statements of Income. Securities sold not yet purchased totaled $1.3 million and $3.2 million at June 30, 2022 and December 31, 2021, respectively, and are classified within the Other liabilities line of the Company’s Consolidated Balance Sheets.

The table below provides detailed information for Other securities at June 30, 2022 and December 31, 2021 (in thousands):

Investment in FRB stock is based on the capital structure of the investing bank, and investment in FHLB stock is mainly tied to the level of borrowings from the FHLB. These holdings are carried at cost. Equity securities with readily determinable fair values are generally traded on an exchange and market prices are readily available. Equity securities without readily determinable fair values include equity investments which are held by a subsidiary qualified as a Small Business Investment Company, as well as investments in low-income housing partnerships within the areas the Company serves. Unrealized gains or losses on equity securities with and without readily determine fair values are recognized in the Investment securities gains, net line of the Company’s Consolidated Statements of Income.

The table below presents the components of Investments securities gains, net for the three and six months ended June 30, 2022 and June 30, 2021 (in thousands):

	Three Months Ended June 30,					Six Months Ended June 30,
	2022			2021		2022			2021
Investment securities gains, net
Available-for-sale debt securities:
Gains realized on sales	$	—		$	1,300	$	—		$	4,020
Equity securities with readily determinable fair values:
Fair value adjustments, net		(5,407	)		8,738		(7,129	)		(5,180	)
Equity securities without readily determinable fair values:
Fair value adjustments, net		(35	)		5,417		1,165			8,279
Sales		66,162			—		66,162			—
Total investment securities gains, net	$	60,720		$	15,455	$	60,198		$	7,119

During June 2022, the Company sold the entirety of its Visa Inc. Class B common shares in a cash transaction which resulted in a pre-tax gain of $66.2 million. Prior to the sale, the Visa Inc. Class B shares had no carrying value on the Company’s Consolidated Balance Sheets as the Company had no historical cost basis in the shares.