Debt Securities (Tables)

6 Months Ended

Jun. 30, 2022

Debt Securities

Schedule of amortized cost, unrealized gains and losses and fair values of securities classified available for sale and held to maturity

The tables below provide the amortized cost, unrealized gains and losses, and fair values of debt securities summarized by major category (dollars in thousands):

	As of June 30, 2022
	Amortized		Unrealized				Fair
	Cost		Gross Gains		Gross Losses		Value
Debt securities available for sale
U.S. Treasury securities	$	151,222	$	1	$	(4,083)	$	147,140
Obligations of U.S. government corporations and agencies		29,867		53		(81)		29,839
Obligations of states and political subdivisions		305,545		455		(18,388)		287,612
Asset-backed securities		490,932		—		(22,803)		468,129
Commercial mortgage-backed securities		105,584		—		(7,222)		98,362
Residential mortgage-backed securities		1,599,774		50		(158,667)		1,441,157
Corporate debt securities		293,667		49		(21,309)		272,407
Total debt securities available for sale	$	2,976,591	$	608	$	(232,553)	$	2,744,646
Debt securities held to maturity
Commercial mortgage-backed securities	$	492,924	$	—	$	(38,687)	$	454,237
Residential mortgage-backed securities		460,088		—		(37,587)		422,501
Total debt securities held to maturity	$	953,012	$	—	$	(76,274)	$	876,738

	As of December 31, 2021
	Amortized		Unrealized				Fair
	Cost		Gross Gains		Gross Losses		Value
Debt securities available for sale
U.S. Treasury securities	$	166,768	$	41	$	(1,047)	$	165,762
Obligations of U.S. government corporations and agencies		37,579		891		—		38,470
Obligations of states and political subdivisions		300,602		7,760		(1,493)		306,869
Asset-backed securities		492,055		295		(164)		492,186
Commercial mortgage-backed securities		625,339		3,425		(13,766)		614,998
Residential mortgage-backed securities		2,095,104		8,889		(34,680)		2,069,313
Corporate debt securities		296,076		1,081		(3,504)		293,653
Total debt securities available for sale	$	4,013,523	$	22,382	$	(54,654)	$	3,981,251

Schedule of amortized cost and fair value of debt securities available for sale and held to maturity by contractual maturity

	As of June 30, 2022
	Amortized		Fair
	Cost		Value
Debt securities available for sale
Due in one year or less	$	191,190	$	189,295
Due after one year through five years		421,603		399,194
Due after five years through ten years		326,834		307,336
Due after ten years		2,036,964		1,848,821
Debt securities available for sale	$	2,976,591	$	2,744,646
Debt securities held to maturity
Due after one year through five years		48,232		46,533
Due after five years through ten years		66,107		61,995
Due after ten years		838,673		768,210
Debt securities held to maturity	$	953,012	$	876,738

Schedule of realized gains and losses related to sales of securities

Realized gains and losses related to sales and calls of debt securities available for sale are summarized as follows (dollars in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Realized gains and losses on debt securities
Gross gains on debt securities	$	1	$	499	$	114	$	524
Gross (losses) on debt securities		(5)		(405)		(12)		(405)
Realized net gains (losses) on debt securities (1)	$	(4)	$	94	$	102	$	119

(1) Net gains (losses) on sales of securities reported in the unaudited Consolidated Statements of Income include sales of equity securities, excluded in this table.

Schedule of securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position

The following information pertains to debt securities with gross unrealized losses, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (dollars in thousands):

	As of June 30, 2022
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
Debt securities available for sale
U.S. Treasury securities	$	21,976	$	(154)	$	124,094	$	(3,929)	$	146,070	$	(4,083)
Obligations of U.S. government corporations and agencies		17,078		(81)		—		—		17,078		(81)
Obligations of states and political subdivisions		192,737		(16,868)		11,056		(1,520)		203,793		(18,388)
Asset-backed securities		465,293		(22,632)		2,835		(171)		468,128		(22,803)
Commercial mortgage-backed securities		91,564		(6,560)		6,798		(662)		98,362		(7,222)
Residential mortgage-backed securities		1,035,112		(96,222)		399,554		(62,445)		1,434,666		(158,667)
Corporate debt securities		178,170		(14,790)		83,656		(6,519)		261,826		(21,309)
Debt securities available for sale with gross unrealized losses	$	2,001,930	$	(157,307)	$	627,993	$	(75,246)	$	2,629,923	$	(232,553)
Debt securities held to maturity
Commercial mortgage-backed securities	$	241,060	$	(19,840)	$	213,177	$	(18,847)	$	454,237	$	(38,687)
Residential mortgage-backed securities		382,897		(33,909)		39,603		(3,678)		422,500		(37,587)
Debt securities held to maturity with gross unrealized losses	$	623,957	$	(53,749)	$	252,780	$	(22,525)	$	876,737	$	(76,274)

	As of December 31, 2021
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
Debt securities available for sale
U.S. Treasury securities	$	163,653	$	(1,047)	$	—	$	—	$	163,653	$	(1,047)
Obligations of states and political subdivisions		92,680		(1,493)		—		—		92,680		(1,493)
Asset-backed securities		89,983		(164)		—		—		89,983		(164)
Commercial mortgage-backed securities		389,078		(10,186)		85,905		(3,580)		474,983		(13,766)
Residential mortgage-backed securities		1,700,187		(33,453)		20,538		(1,227)		1,720,725		(34,680)
Corporate debt securities		241,153		(3,504)		—		—		241,153		(3,504)
Debt securities available for sale with gross unrealized losses	$	2,676,734	$	(49,847)	$	106,443	$	(4,807)	$	2,783,177	$	(54,654)

Additional information about debt securities in an unrealized loss position is presented in the tables below (dollars in thousands):

	As of June 30, 2022
	Available for Sale			Held to Maturity			Total
Debt securities with gross unrealized losses, fair value	$	2,629,923		$	876,737		$	3,506,660
Gross unrealized losses on debt securities	$	232,553		$	76,274		$	308,827
Ratio of gross unrealized losses to debt securities with gross unrealized losses		8.8	%		8.7	%		8.8	%
Count of debt securities		1,177			55			1,232
Count of debt securities in an unrealized loss position		881			55			936

	As of December 31, 2021
	Available for Sale			Held to Maturity		Total
Debt securities with gross unrealized losses, fair value	$	2,783,177		$	—	$	2,783,177
Gross unrealized losses on debt securities	$	54,654		$	—	$	54,654
Ratio of gross unrealized losses to debt securities with gross unrealized losses		2.0	%		—		2.0	%
Count of debt securities		1,252			—		1,252
Count of debt securities in an unrealized loss position		373			—		373