INVESTMENTS (Tables)

3 Months Ended

Mar. 31, 2019

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 March 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	$	0	$	(1	)	$	98
Securities of U.S. government agencies and corporations	0		0		0			0		30,880		74		(355		)	30,599
Mortgage-backed securities - residential	24,937		72		(671		)	24,338		557,730		4,566		(3,449		)	558,847
Mortgage-backed securities - commercial	109,826		0		(4,414		)	105,412		464,611		1,821		(2,988		)	463,444
Collateralized mortgage obligations	11,936		0		(429		)	11,507		919,486		9,214		(3,067		)	925,633
Obligations of state and other political subdivisions	11,606		440		(228		)	11,818		542,265		12,496		(504		)	554,257
Asset-backed securities	0		0		0			0		502,018		1,180		(1,790		)	501,408
Other securities	0		0		0			0		78,996		853		(324		)	79,525
Total	$	158,305	$	512	$	(5,742	)	$	153,075	$	3,096,085	$	30,204	$	(12,478	)	$	3,113,811

The following is a summary of HTM and AFS investment securities as of December 31, 2018:

	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	$	0	$	(2	)	$	97
Securities of U.S. government agencies and corporations	0		0		0			0		32,095		57		(233		)	31,919
Mortgage-backed securities - residential	25,565		0		(1,045		)	24,520		565,071		691		(7,163		)	558,599
Mortgage-backed securities - commercial	147,780		258		(4,385		)	143,653		423,797		819		(3,581		)	421,035
Collateralized mortgage obligations	12,540		0		(633		)	11,907		928,586		4,319		(6,158		)	926,747
Obligations of state and other political subdivisions	243,443		1,954		(1,359		)	244,038		257,300		2,554		(1,429		)	258,425
Asset-backed securities	0		0		0			0		511,430		611		(2,810		)	509,231
Other securities	0		0		0			0		73,948		358		(1,104		)	73,202
Total	$	429,328	$	2,212	$	(7,422	)	$	424,118	$	2,792,326	$	9,409	$	(22,480	)	$	2,779,255

Summary of Investment Securities by Estimated Maturity

The following table provides a summary of investment securities by contractual maturity as of March 31, 2019, 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	$	18,503	$	18,522
Due after one year through five years	0		0		52,079		52,547
Due after five years through ten years	4,247		4,579		162,531		165,532
Due after ten years	7,359		7,239		419,127		427,878
Mortgage-backed securities - residential	24,937		24,338		557,730		558,847
Mortgage-backed securities - commercial	109,826		105,412		464,611		463,444
Collateralized mortgage obligations	11,936		11,507		919,486		925,633
Asset-backed securities	0		0		502,018		501,408
Total	$	158,305	$	153,075	$	3,096,085	$	3,113,811

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, aggregated by investment category and the length of time the individual securities have been in a continuous loss position:

	March 31, 2019
	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		$	98	$	(1	)	$	98	$	(1	)
Securities of U.S. Government agencies and corporations	6,046		(77		)	13,946		(278		)	19,992		(355		)
Mortgage-backed securities - residential	12,585		(322		)	239,305		(3,798		)	251,890		(4,120		)
Mortgage-backed securities - commercial	140,670		(264		)	195,282		(7,138		)	335,952		(7,402		)
Collateralized mortgage obligations	90,610		(431		)	212,286		(3,065		)	302,896		(3,496		)
Obligations of state and other political subdivisions	12,080		(30		)	42,954		(702		)	55,034		(732		)
Asset-backed securities	224,565		(1,325		)	48,376		(465		)	272,941		(1,790		)
Other securities	8,636		(78		)	7,545		(246		)	16,181		(324		)
Total	$	495,192	$	(2,527	)	$	759,792	$	(15,693	)	$	1,254,984	$	(18,220	)

	December 31, 2018
	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		$	97	$	(2	)	$	97	$	(2	)
Securities of U.S. Government agencies and corporations	0		0			16,777		(233		)	16,777		(233		)
Mortgage-backed securities - residential	186,029		(935		)	264,795		(7,273		)	450,824		(8,208		)
Mortgage-backed securities - commercial	147,754		(369		)	232,363		(7,597		)	380,117		(7,966		)
Collateralized mortgage obligations	194,795		(1,546		)	240,514		(5,245		)	435,309		(6,791		)
Obligations of state and other political subdivisions	62,805		(299		)	86,644		(2,489		)	149,449		(2,788		)
Asset-backed securities	336,437		(2,312		)	37,105		(498		)	373,542		(2,810		)
Other securities	33,752		(884		)	4,570		(220		)	38,322		(1,104		)
Total	$	961,572	$	(6,345	)	$	882,865	$	(23,557	)	$	1,844,437	$	(29,902	)