Investment Securities

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

The following table presents the amortized cost and estimated fair values of investment securities for the periods presented:


	June 30, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available for Sale	(in thousands)
U.S. Government securities	$	376,505	$	—	$	(5,239)	$	371,266

State and municipal securities	1,239,591		501		(156,615)		1,083,477
Corporate debt securities	413,487		186		(20,112)		393,561
Collateralized mortgage obligations	154,558		10		(6,465)		148,103
Residential mortgage-backed securities	213,567		167		(18,375)		195,359
Commercial mortgage-backed securities	636,380		28		(49,336)		587,072


Total	$	3,034,088	$	892	$	(256,142)	$	2,778,838

Held to Maturity

Residential mortgage-backed securities	$	466,076	$	297	$	(35,444)	$	430,929
Commercial mortgage-backed securities	872,887		12		(88,503)		784,396
Total	$	1,338,963	$	309	$	(123,947)	$	1,215,325


	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available for Sale	(in thousands)
U.S. Government securities	$	127,831	$	—	$	(213)	$	127,618

State and municipal securities	1,139,187		50,161		(678)		1,188,670
Corporate debt securities	373,482		13,009		(358)		386,133
Collateralized mortgage obligations	206,532		3,581		(754)		209,359
Residential mortgage-backed securities	231,607		1,224		(3,036)		229,795
Commercial mortgage-backed securities	974,541		6,141		(9,534)		971,148
Auction rate securities	76,350		—		(1,683)		74,667
Total	$	3,129,530	$	74,116	$	(16,256)	$	3,187,390



Held to Maturity

Residential mortgage-backed securities	$	404,958	$	11,022	$	(7,067)	$	408,913
Commercial mortgage-backed securities	575,426		—		(18,472)		556,954
Total	$	980,384	$	11,022	$	(25,539)	$	965,867

During the first quarter of 2022, all ARCs were sold.

On May 1, 2022, the Corporation transferred certain residential mortgage-backed securities and commercial mortgage-backed securities from AFS to HTM classification as permitted by ASU 2019-04. The estimated fair value of the securities transferred was $415.2 million, and the amortized cost of the securities was $479.0 million.

Securities carried at $1.8 billion at June 30, 2022 and $2.5 billion at December 31, 2021 were pledged as collateral to secure public and trust deposits.

The amortized cost and estimated fair values of debt securities as of June 30, 2022, by contractual maturity, are shown in the following table. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay with or without call or prepayment penalties.


		June 30, 2022
		Available for Sale				Held to Maturity
		Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(in thousands)
Due in one year or less		$	160,087	$	160,007	$	—	$	—
Due from one year to five years		280,399		274,819		—		—
Due from five years to ten years		447,924		427,025		—		—
Due after ten years		1,141,173		986,453		—		—
		2,029,583		1,848,304		—		—
Residential mortgage-backed securities(1)		213,567		195,359		466,076		430,929
Commercial mortgage-backed securities(1)		636,380		587,072		872,887		784,396
Collateralized mortgage obligations(1)		154,558		148,103		—		—
Total		$	3,034,088	$	2,778,838	$	1,338,963	$	1,215,325
(1) Maturities for mortgage-backed securities and collateralized mortgage obligations are dependent upon the interest rate environment and prepayments on the underlying loans.

The following table presents information related to gross realized gains and losses on the sales of securities for the periods presented:


	Gross Realized Gains		Gross Realized Losses		Net Gains
Three months ended	(in thousands)
June 30, 2022	$	8	$	—	$	8
June 30, 2021	465		(429)		36

Six months ended
June 30, 2022	$	1,554	$	(1,527)	$	27
June 30, 2021	34,481		(970)		33,511

During the first quarter of 2021, the Corporation completed a balance sheet restructuring that included a $34.0 million gain on the sale of Visa Shares, offset by losses on other securities of $0.4 million, primarily in connection with the sale of $24.6 million of ARCs.

The following tables present the gross unrealized losses and estimated fair values of investment securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position for the periods presented:


	June 30, 2022
	Less than 12 months					12 months or longer					Total
	Number of Securities	Estimated Fair Value		Unrealized Losses		Number of Securities	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses

Available for Sale		($ in thousands)
U.S. Government securities	4	$	371,266	$	(5,239)	—	$	—	$	—	$	371,266	$	(5,239)

State and municipal securities	355	989,029		(149,910)		6	24,248		(6,705)		1,013,277		(156,615)
Corporate debt securities	55	363,657		(20,112)		—	—		—		363,657		(20,112)
Collateralized mortgage obligations	72	140,957		(6,465)		—	—		—		140,957		(6,465)
Residential mortgage-backed securities	28	130,063		(9,194)		4	60,469		(9,181)		190,532		(18,375)
Commercial mortgage-backed securities	75	539,431		(45,245)		1	24,134		(4,091)		563,565		(49,336)

Total available for sale	589	$	2,534,403	$	(236,165)	11	$	108,851	$	(19,977)	$	2,643,254	$	(256,142)

Held to Maturity

Residential mortgage-backed securities	58	$	181,966	$	(4,790)	12	$	152,702	$	(30,654)	$	334,668	$	(35,444)
Commercial mortgage-backed securities	39	454,603		(32,031)		20	301,951		(56,472)		756,554		(88,503)
Total	97	$	636,569	$	(36,821)	32	$	454,653	$	(87,126)	$	1,091,222	$	(123,947)


	December 31, 2021
	Less than 12 months					12 months or longer					Total
	Number of Securities	Estimated Fair Value		Unrealized Losses		Number of Securities	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
Available for Sale	($ in thousands)
U.S Government Securities	2	$	127,618	$	(213)	—	$	—	$	—	$	127,618	$	(213)

State and municipal securities	29	82,731		(678)		—	—		—		82,731		(678)
Corporate debt securities	6	43,068		(358)		—	—		—		43,068		(358)
Collateralized mortgage obligations	4	28,517		(754)		—	—		—		28,517		(754)
Residential mortgage-backed securities	7	123,687		(2,388)		1	16,669		(648)		140,356		(3,036)
Commercial mortgage-backed securities	41	512,312		(9,534)		—	—		—		512,312		(9,534)
Auction rate securities	—	—		—		118	74,667		(1,683)		74,667		(1,683)
Total available for sale	89	$	917,933	$	(13,925)	119	$	91,336	$	(2,331)	$	1,009,269	$	(16,256)



Held to Maturity

Residential mortgage-backed securities	14	$	205,969	$	(7,067)	—	$	—	$	—	$	205,969	$	(7,067)
Commercial mortgage-backed securities	36	556,954		(18,472)		—	—		—		556,954		(18,472)
Total	50	$	762,923	$	(25,539)	—	$	—	$	—	$	762,923	$	(25,539)

The Corporation's collateralized mortgage obligations and mortgage-backed securities have contractual terms that generally do not permit the issuer to settle the securities at a price less than the amortized cost of the investment. The change in fair value of these securities is attributable to changes in interest rates and not credit quality. The Corporation does not have the intent to sell and does not believe it will more likely than not be required to sell any of these securities prior to a recovery of their fair value to amortized cost. Therefore, the Corporation does not have an ACL for these investments as of June 30, 2022 and December 31, 2021.

Based on management’s evaluations, no ACL was required for state and municipal securities as of June 30, 2022 or December 31, 2021. The Corporation does not have the intent to sell and does not believe it will more likely than not be required to sell any of these securities prior to a recovery of their fair value to amortized cost, which may be at maturity.

As of June 30, 2022 and December 31, 2021, all corporate debt securities were rated above investment grade. Based on the payment status, rating and management's evaluation of these securities, no ACL was required for corporate debt securities as of June 30, 2022 or December 31, 2021.

As of December 31, 2021, all ARCs were rated above investment grade. All of the loans underlying the ARCs had principal payments that were guaranteed by the federal government. Based on the payment status, rating and management's evaluation of these securities, no ACL was required for ARCs as of December 31, 2021.