Securities (Tables)

6 Months Ended

Jun. 30, 2020

Securities

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

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

			Gross		Gross			Allowance
	Amortized		Unrealized		Unrealized			for Credit	Fair
June 30, 2020:	Cost		Gains		Losses			Losses	Value
Debt securities available for sale
U.S. Treasury securities	$	32,597	$	639	$	—	$	—	$	33,236
Obligations of U.S. government corporations and agencies		77,349		2,752		(57)		—		80,044
Obligations of states and political subdivisions		272,885		10,047		(38)		—		282,894
Commercial mortgage-backed securities		230,352		10,956		(3)		—		241,305
Residential mortgage-backed securities		940,842		29,475		(124)		—		970,193
Corporate debt securities		87,404		1,826		(36)		—		89,194
Total	$	1,641,429	$	55,695	$	(258)	$	—	$	1,696,866

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2019:	Cost		Gains		Losses		Value
Debt securities available for sale
U.S. Treasury securities	$	51,472	$	265	$	—	$	51,737
Obligations of U.S. government corporations and agencies		160,364		2,684		(48)		163,000
Obligations of states and political subdivisions		262,492		5,810		(11)		268,291
Commercial mortgage-backed securities		137,733		1,700		(146)		139,287
Residential mortgage-backed securities		912,308		10,282		(624)		921,966
Corporate debt securities		102,696		1,280		—		103,976
Total	$	1,627,065	$	22,021	$	(829)	$	1,648,257

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

The amortized cost and fair value of debt securities, by contractual maturity or pre-refunded date, are shown below. Mortgages underlying mortgage-backed securities may be called or prepaid; therefore, actual maturities could differ from the contractual maturities. All mortgage-backed securities were issued by U.S. government agencies and corporations (dollars in thousands).

	Debt securities available for sale
	Amortized		Fair
June 30, 2020:	Cost		Value
Due in one year or less	$	132,192	$	133,749
Due after one year through five years		241,337		250,413
Due after five years through ten years		241,496		252,566
Due after ten years		1,026,404		1,060,138
Total	$	1,641,429	$	1,696,866

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,
	2020		2019		2020		2019
Gross security gains	$	146	$	391	$	1,707	$	391
Gross security (losses)		(3)		(400)		(8)		(583)
Net gains (losses) on sales of securities(1)	$	143	$	(9)	$	1,699	$	(192)

(1) Net (losses) gains on sales of securities reported on the unaudited Consolidated Statements of Income includes sale 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):

	Less than 12 months, gross				12 months or more, gross				Total, gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
June 30, 2020:	Value		Losses		Value		Losses		Value		Losses
Debt securities available for sale
U.S. Treasury securities	$	—	$	—	$	—	$	—	$	—	$	—
Obligations of U.S. government corporations and agencies		5,648		(57)		—		—		5,648		(57)
Obligations of states and political subdivisions		6,432		(38)		—		—		6,432		(38)
Commercial mortgage-backed securities		4,963		(3)		—		—		4,963		(3)
Residential mortgage-backed securities		35,830		(120)		937		(4)		36,767		(124)
Corporate debt securities		4,222		(36)		—		—		4,222		(36)
Total temporarily impaired securities	$	57,095	$	(254)	$	937	$	(4)	$	58,032	$	(258)

	Less than 12 months, gross				12 months or more, gross				Total, gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2019:	Value		Losses		Value		Losses		Value		Losses
Debt securities available for sale
U.S. Treasury securities	$	—	$	—	$	—	$	—	$	—	$	—
Obligations of U.S. government corporations and agencies		6,362		(48)		—		—		6,362		(48)
Obligations of states and political subdivisions(1)		4,981		(11)		1,548		—		6,529		(11)
Commercial mortgage-backed securities		33,322		(144)		2,044		(2)		35,366		(146)
Residential mortgage-backed securities		78,326		(245)		50,259		(379)		128,585		(624)
Corporate debt securities		—		—		—		—		—		—
Total temporarily impaired securities	$	122,991	$	(448)	$	53,851	$	(381)	$	176,842	$	(829)

(1) Unrealized losses for 12 months or more, gross, was less than one thousand dollars.