Securities

The carrying values of investment securities at March 31, 2019 and December 31, 2018 are summarized in the following table (dollars in thousands):



	March 31, 2019				December 31, 2018
	Amount		Percent		Amount		Percent
Securities available for sale
U.S. Treasury	$	91,573	28.27	%	$	83,155	26.07	%
Other securities (FHLB, FHLMC and FNMA)	27,531		8.50		34,871		10.93
State and political subdivisions	204,813		63.23		200,900		63.00
Total securities available for sale	$	323,917	100.00	%	$	318,926	100.00	%

Investment securities have been classified in the consolidated balance sheets according to management’s intent. Available-for-sale securities consist of debt securities not classified as trading or held to maturity. Available-for-sale securities are stated at fair value, and unrealized holding gains and losses, net of the related deferred tax effect, are reported as a separate component of stockholders' equity. There were no trading or held to maturity securities as of March 31, 2019 or December 31, 2018. The carrying amount of available-for-sale securities and their approximate fair values were as follows as of March 31, 2019 and December 31, 2018 (in thousands):



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
March 31, 2019:
U.S. Treasury	$	91,181	$	726	$	(334	)	$	91,573
Other securities (FHLB, FHLMC and FNMA)	27,846		—		(315		)	27,531
State and political subdivisions	204,331		1,189		(707		)	204,813
Total	$	323,358	$	1,915	$	(1,356	)	$	323,917
December 31, 2018:
U.S. Treasury	$	83,839	$	124	$	(808	)	$	83,155
Other securities (FHLB, FHLMC and FNMA)	35,371		—		(500		)	34,871
State and political subdivisions	202,450		278		(1,828		)	200,900
Total	$	321,660	$	402	$	(3,136	)	$	318,926

The amortized cost and estimated fair value of available-for-sale securities classified according to their contractual maturities at March 31, 2019, were as follows (in thousands):



	Amortized Cost		Fair Value
Due in one year or less	$	57,358	$	57,169
Due after one year through five years	186,161		186,388
Due after five years through ten years	79,278		79,787
Due over ten years	561		573
Total	$	323,358	$	323,917

As of March 31, 2019 investment securities with a carrying value of $11.72 million were pledged to collateralize derivative financial instruments and other borrowings.

The following table shows the fair value, gross unrealized losses and the percentage of fair value represented by gross unrealized losses of applicable investment securities owned by the Company, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2019 and December 31, 2018 (in thousands):



	Less than 12 months								12 months or more								Total
March 31, 2019 Description of Securities	#	Fair Value		Unrealized Loss			%		#	Fair Value		Unrealized Loss			%		#	Fair Value		Unrealized Loss			%
U.S. Treasury	—	$	—	$	—		—	%	19	$	46,923	$	(334	)	0.71	%	19	$	46,923	$	(334	)	0.71	%

Other securities (FHLB, FHLMC and FNMA)	—	—		—			—		11	27,531		(315		)	1.14		11	27,531		(315		)	1.14

State and political subdivisions	59	30,332		(148		)	0.49		262	62,104		(559		)	0.90		321	92,436		(707		)	0.76

Total temporarily impaired securities	59	$	30,332	$	(148	)	0.49	%	292	$	136,558	$	(1,208	)	0.88	%	351	$	166,890	$	(1,356	)	0.81	%



	Less than 12 months								12 months or more								Total
December 31, 2018 Description of Securities	#	Fair Value		Unrealized Loss			%		#	Fair Value		Unrealized Loss			%		#	Fair Value		Unrealized Loss			%
U.S. Treasury	6	$	14,644	$	(49	)	0.33	%	19	$	46,443	$	(759	)	1.63	%	25	$	61,087	$	(808	)	1.32	%

Other securities (FHLB, FHLMC and FNMA)	—	—		—			—		14	34,871		(500		)	1.43		14	34,871		(500		)	1.43

State and political subdivisions	113	31,022		(162		)	0.52		325	77,921		(1,666		)	2.14		438	108,943		(1,828		)	1.68

Total temporarily impaired securities	119	$	45,666	$	(211	)	0.46	%	358	$	159,235	$	(2,925	)	1.84	%	477	$	204,901	$	(3,136	)	1.53	%

The Company considered the following information in reaching the conclusion that the impairments disclosed in the table above are temporary and not other-than-temporary impairments. None of the unrealized losses in the above table was due to the deterioration in the credit quality of any of the issues that might result in the non-collection of contractual principal and interest. The unrealized losses are due to changes in interest rates. The Company has not recognized any unrealized loss in income because management does not have the intent to sell the securities included in the previous table. Management has concluded that it is more likely than not that the Company will not be required to sell these securities prior to recovery of the amortized cost basis.