Investment Securities (Tables)

9 Months Ended

Sep. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Investment Securities

The amortized cost and fair value of investment securities that are classified as held-to-maturity (“HTM”) and available-for-sale (“AFS”) are as follows:

	September 30, 2019									December 31, 2018
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
Held-to-Maturity
U.S. Government agencies	$	—	$	—	$	—		$	—	$	16,990	$	—	$	(49	)	$	16,941
Mortgage-backed securities	11,549		93		(42		)	11,600		13,346		5		(412		)	12,939
State and political subdivisions	28,692		931		—			29,623		256,863		3,029		(954		)	258,938
Other securities	1,996		83		—			2,079		1,995		17		—			2,012
Total HTM	$	42,237	$	1,107	$	(42	)	$	43,302	$	289,194	$	3,051	$	(1,415	)	$	290,830
Available-for-Sale
U.S. Government agencies	$	177,712	$	1,629	$	(1,202	)	$	178,139	$	157,523	$	518	$	(3,740	)	$	154,301
Mortgage-backed securities	1,332,130		9,405		(3,741		)	1,337,794		1,552,487		3,097		(32,684		)	1,522,900
State and political subdivisions	658,984		22,290		(72		)	681,202		320,142		171		(5,470		)	314,843
Other securities	158,280		719		—			158,999		157,471		2,251		(14		)	159,708
Total AFS	$	2,327,106	$	34,043	$	(5,015	)	$	2,356,134	$	2,187,623	$	6,037	$	(41,908	)	$	2,151,752

Gross Unrealized Losses and Fair Value of Investments

The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2019: 

	Less Than 12 Months					12 Months or More					Total
(In thousands)	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
Held-to-Maturity
Mortgage-backed securities	$	3,408	$	(15	)	$	2,575	$	(27	)	$	5,983	$	(42	)
State and political subdivisions	635		—			15		—			650		—
Total HTM	$	4,043	$	(15	)	$	2,590	$	(27	)	$	6,633	$	(42	)
Available-for-Sale
U.S. Government agencies	$	16,662	$	(36	)	$	90,974	$	(1,166	)	$	107,636	$	(1,202	)
Mortgage-backed securities	133,538		(528		)	435,207		(3,213		)	568,745		(3,741		)
State and political subdivisions	24,278		(41		)	3,297		(31		)	27,575		(72		)
Total AFS	$	174,478	$	(605	)	$	529,478	$	(4,410	)	$	703,956	$	(5,015	)

Income Earned on Securities

Income earned on securities for the three and nine months ended September 30, 2019 and 2018, is as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
(In thousands)	2019		2018		2019		2018
Taxable:
Held-to-maturity	$	248	$	528	$	975	$	1,641
Available-for-sale	10,166		10,364		34,422		29,614
Non-taxable:
Held-to-maturity	83		1,828		1,334		5,661
Available-for-sale	4,870		1,920		12,542		4,642
Total	$	15,367	$	14,640	$	49,273	$	41,558

Amortized Cost and Estimated Fair Value by Maturity of Securities

The amortized cost and estimated fair value by maturity of securities are shown in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. 

	Held-to-Maturity				Available-for-Sale
(In thousands)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
One year or less	$	5,039	$	5,057	$	7,599	$	7,605
After one through five years	17,346		17,703		70,442		70,750
After five through ten years	5,561		5,858		139,421		142,101
After ten years	2,742		3,084		632,504		652,404
Securities not due on a single maturity date	11,549		11,600		1,332,130		1,337,794
Other securities (no maturity)	—		—		145,010		145,480
Total	$	42,237	$	43,302	$	2,327,106	$	2,356,134