Securities

6 Months Ended

Jun. 30, 2019

Investments Debt And Equity Securities [Abstract]

Securities

(3) SECURITIES

The following table summarizes the amortized cost and estimated fair values of debt securities held for investment:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
June 30, 2019	(Dollars in thousands)
Mortgage backed securities (1)	$	112	$	6	$	—		$	118
States and political subdivisions		1,385		1		(1	)		1,385
Other securities		500		—		—			500
Total	$	1,997	$	7	$	(1	)	$	2,003
December 31, 2018
Mortgage backed securities (1)	$	133	$	5	$	—		$	138
States and political subdivisions		795		—		—			795
Other securities		500		—		—			500
Total	$	1,428	$	5	$	—		$	1,433

The following table summarizes the amortized cost and estimated fair values of debt securities available for sale:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
June 30, 2019	(Dollars in thousands)
U.S. treasuries	$	353,618	$	5,371	$	(355	)	$	358,634
U.S. federal agencies		26,169		12		(26	)		26,155
Mortgage backed securities (1)		15,646		138		(565	)		15,219
States and political subdivisions		22,820		335		(6	)		23,149
Total	$	418,253	$	5,856	$	(952	)	$	423,157
December 31, 2018
U.S. treasuries	$	699,882	$	1,108	$	(3,524	)	$	697,466
U.S. federal agencies		30,079		—		(160	)		29,919
Mortgage backed securities (1)		16,367		114		(573	)		15,908
States and political subdivisions		27,246		277		(112	)		27,411
Total	$	773,574	$	1,499	$	(4,369	)	$	770,704

(1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies.

The maturities of debt securities held for investment and available for sale are summarized in the following table using contractual maturities. Actual maturities may differ from contractual maturities due to obligations that are called or prepaid. For purposes of the maturity table, mortgage-backed securities, which are not due at a single maturity date, have been presented at their contractual maturity.

	June 30, 2019				December 31, 2018
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(Dollars in thousands)
Held for Investment
Contractual maturity of debt securities:
Within one year	$	300	$	301	$	495	$	495
After one year but within five years		1,146		1,147		369		370
After five years but within ten years		549		553		562		565
After ten years		2		2		2		3
Total	$	1,997	$	2,003	$	1,428	$	1,433
Available for Sale
Contractual maturity of debt securities:
Within one year	$	103,395	$	103,084	$	411,256	$	410,327
After one year but within five years		270,900		276,333		313,416		311,924
After five years but within ten years		6,355		6,606		7,524		7,685
After ten years		37,603		37,134		41,378		40,768
Total debt securities	$	418,253	$	423,157	$	773,574	$	770,704

The following table is a summary of the Company’s book value of securities that were pledged as collateral for public funds on deposit, repurchase agreements and for other purposes as required or permitted by law:

	June 30, 2019		December 31, 2018
	(Dollars in thousands)
Book value of pledged securities	$	402,756	$	472,053