INVESTMENTS (Tables)

9 Months Ended

Sep. 30, 2020

Investments, Debt and Equity Securities [Abstract]

Summary of Held-To-Maturity and Available-For-Sale Investment Securities

The following is a summary of HTM and AFS investment securities as of September 30, 2020:

	Held-to-maturity								Available-for-sale
(Dollars in thousands)	Amortized cost		Unrecognized gain		Unrecognized loss		Fair value		Amortized cost		Unrealized gain		Unrealized loss		Fair value
U.S. Treasuries	$	0	$	0	$	0	$	0	$	99	$	4	$	0	$	103
Securities of U.S. government agencies and corporations	0		0		0		0		59		1		0		60
Mortgage-backed securities - residential	16,069		250		0		16,319		393,395		16,084		(59)		409,420
Mortgage-backed securities - commercial	84,701		3,834		0		88,535		550,408		10,943		(4,791)		556,560
Collateralized mortgage obligations	6,987		93		0		7,080		680,581		25,891		(339)		706,133
Obligations of state and other political subdivisions	10,315		1,192		0		11,507		761,589		41,007		(599)		801,997
Asset-backed securities	0		0		0		0		433,811		2,963		(2,978)		433,796
Other securities	0		0		0		0		95,995		1,496		(597)		96,894
Total	$	118,072	$	5,369	$	0	$	123,441	$	2,915,937	$	98,389	$	(9,363)	$	3,004,963

The following is a summary of HTM and AFS investment securities as of December 31, 2019:

	Held-to-maturity								Available-for-sale
(Dollars in thousands)	Amortized cost		Unrecognized gain		Unrecognized loss		Fair value		Amortized cost		Unrealized gain		Unrealized loss		Fair value
U.S. Treasuries	$	0	$	0	$	0	$	0	$	99	$	1	$	0	$	100
Securities of U.S. government agencies and corporations	0		0		0		0		156		2		0		158
Mortgage-backed securities - residential	20,818		122		(174)		20,766		421,945		9,709		(99)		431,555
Mortgage-backed securities - commercial	101,267		571		(1,225)		100,613		474,174		4,988		(2,644)		476,518
Collateralized mortgage obligations	9,763		0		(108)		9,655		769,076		16,753		(385)		785,444
Obligations of state and other political subdivisions	11,014		804		(31)		11,787		652,986		23,729		(462)		676,253
Asset-backed securities	0		0		0		0		400,081		1,414		(1,064)		400,431
Other securities	0		0		0		0		79,781		1,959		(115)		81,625
Total	$	142,862	$	1,497	$	(1,538)	$	142,821	$	2,798,298	$	58,555	$	(4,769)	$	2,852,084

Summary of Investment Securities by Estimated Maturity

The following table provides a summary of investment securities by contractual maturity as of September 30, 2020, except for residential and commercial mortgage-backed securities, collateralized mortgage obligations and asset-backed securities, which are shown as single totals due to the unpredictability of the timing in principal repayments.

	Held-to-maturity				Available-for-sale
(Dollars in thousands)	Amortized cost		Fair value		Amortized cost		Fair value
By Contractual Maturity:
Due in one year or less	$	0	$	0	$	4,098	$	4,133
Due after one year through five years	0		0		53,902		55,486
Due after five years through ten years	5,784		6,864		183,872		190,863
Due after ten years	4,531		4,643		615,870		648,572
Mortgage-backed securities - residential	16,069		16,319		393,395		409,420
Mortgage-backed securities - commercial	84,701		88,535		550,408		556,560
Collateralized mortgage obligations	6,987		7,080		680,581		706,133
Asset-backed securities	0		0		433,811		433,796
Total	$	118,072	$	123,441	$	2,915,937	$	3,004,963

Age of Gross Unrealized Losses and Associated Fair Value by Investment Category

The following tables provide the fair value and gross unrealized losses on investment securities in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by investment category and the length of time the individual securities have been in a continuous loss position:

	September 30, 2020
	Less than 12 months				12 months or more				Total
(Dollars in thousands)	Fair value		Unrealized loss		Fair value		Unrealized loss		Fair value		Unrealized loss
U.S. Treasuries	$	0	$	0	$	0	$	0	$	0	$	0
Securities of U.S. Government agencies and corporations	0		0		0		0		0		0
Mortgage-backed securities - residential	20,145		(59)		0		0		20,145		(59)
Mortgage-backed securities - commercial	145,885		(1,568)		44,164		(3,223)		190,049		(4,791)
Collateralized mortgage obligations	42,042		(339)		1		0		42,043		(339)
Obligations of state and other political subdivisions	81,678		(599)		0		0		81,678		(599)
Asset-backed securities	138,610		(1,307)		97,031		(1,671)		235,641		(2,978)
Other securities	19,033		(349)		4,577		(248)		23,610		(597)
Total	$	447,393	$	(4,221)	$	145,773	$	(5,142)	$	593,166	$	(9,363)

	December 31, 2019
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(Dollars in thousands)	value		loss		value		loss		value		loss
U.S. Treasuries	$	0	$	0	$	0	$	0	$	0	$	0
Securities of U.S. Government agencies and corporations	0		0		0		0		0		0
Mortgage-backed securities - residential	40,190		(209)		11,063		(64)		51,253		(273)
Mortgage-backed securities - commercial	111,658		(298)		104,069		(3,571)		215,727		(3,869)
Collateralized mortgage obligations	85,248		(297)		30,628		(196)		115,876		(493)
Obligations of state and other political subdivisions	118,623		(457)		7,950		(36)		126,573		(493)
Asset-backed securities	125,889		(553)		54,963		(511)		180,852		(1,064)
Other securities	0		0		5,649		(115)		5,649		(115)
Total	$	481,608	$	(1,814)	$	214,322	$	(4,493)	$	695,930	$	(6,307)