The following tables present the amortized cost and fair value of available-for-sale securities as of the dates presented:



	September 30, 2016									December 31, 2015
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. treasury securities	$	14,944	$	112	$	—		$	15,056	$	14,914	$	27	$	—		$	14,941
Obligations of U.S. government corporations and agencies	246,259		4,665		—			250,924		262,045		1,825		(567		)	263,303
Collateralized mortgage obligations of U.S. government corporations and agencies	134,675		2,785		—			137,460		128,458		693		(316		)	128,835
Residential mortgage-backed securities of U.S. government corporations and agencies	34,685		1,600		—			36,285		39,185		1,091		(151		)	40,125
Commercial mortgage-backed securities of U.S. government corporations and agencies	86,827		1,680		(8		)	88,499		69,697		183		(676		)	69,204
Obligations of states and political subdivisions	124,229		8,307		—			132,536		128,904		5,988		(6		)	134,886
Debt Securities	641,619		19,149		(8		)	660,760		643,203		9,807		(1,716		)	651,294
Marketable equity securities	7,579		2,789		—			10,368		7,579		2,090		—			9,669
Total	$	649,198	$	21,938	$	(8	)	$	671,128	$	650,782	$	11,897	$	(1,716	)	$	660,963

The following tables present the fair value and the age of gross unrealized losses by investment category as of the dates presented:



	September 30, 2016
	Less Than 12 Months						12 Months or More					Total
(dollars in thousands)	Number of Securities	Fair Value		Unrealized Losses			Number of Securities	Fair Value		Unrealized Losses		Number of Securities	Fair Value		Unrealized Losses
U.S. Treasury securities	—	$	—	$	—		—	$	—	$	—	—	$	—	$	—
Obligations of U.S. government corporations and agencies	—	—		—			—	—		—		—	—		—
Collateralized mortgage obligations of U.S. government corporations and agencies	—	—		—			—	—		—		—	—		—
Residential mortgage-backed securities of U.S. government corporations and agencies	—	—		—			—	—		—		—	—		—
Commercial mortgage-backed securities of U.S. government corporations and agencies	1	7,841		(8		)	—	—		—		1	7,841		(8		)
Obligations of states and political subdivisions	—	—		—			—	—		—		—	—		—
Debt Securities	1	7,841		(8		)	—	—		—		1	7,841		(8		)
Marketable equity securities	1	71		—			—	—		—		1	71		—
Total Temporarily Impaired Securities	2	$	7,912	$	(8	)	—	$	—	$	—	2	$	7,912	$	(8	)



	December 31, 2015
	Less Than 12 Months						12 Months or More						Total
(dollars in thousands)	Number of Securities	Fair Value		Unrealized Losses			Number of Securities	Fair Value		Unrealized Losses			Number of Securities	Fair Value		Unrealized Losses
U.S. Treasury securities	—	$	—	$	—		—	$	—	$	—		—	$	—	$	—
Obligations of U.S. government corporations and agencies	10	88,584		(379		)	2	14,542		(188		)	12	103,126		(567		)
Collateralized mortgage obligations of U.S. government corporations and agencies	6	61,211		(316		)	—	—		—			6	61,211		(316		)
Residential mortgage-backed securities of U.S. government corporations and agencies	1	7,993		(151		)	—	—		—			1	7,993		(151		)
Commercial mortgage-backed securities of U.S. government corporations and agencies	5	50,839		(450		)	1	9,472		(226		)	6	60,311		(676		)
Obligations of states and political subdivisions	1	5,370		(6		)	—	—		—			1	5,370		(6		)
Debt Securities	23	213,997		(1,302		)	3	24,014		(414		)	26	238,011		(1,716		)
Marketable equity securities	—	—		—			—	—		—			—	—		—
Total Temporarily Impaired Securities	23	$	213,997	$	(1,302	)	3	$	24,014	$	(414	)	26	$	238,011	$	(1,716	)

We do not believe any individual unrealized loss as of September 30, 2016 represents an other than temporary impairment. As of September 30, 2016, one debt security and one marketable equity security were in an unrealized loss position compared to unrealized losses on 26 debt securities at December 31, 2015. There were no unrealized losses on marketable equity securities at December 31, 2015. These unrealized losses were primarily attributable to changes in interest rates and not related to the credit quality of these securities. All debt securities are determined to be investment grade and are paying principal and interest according to the contractual terms of the security. We do not intend to sell and it is not more likely than not that we will be required to sell any of the securities in an unrealized loss position before recovery of their amortized cost.

The following table displays net unrealized gains and losses, net of tax on securities available for sale included in accumulated other comprehensive (loss)/income, for the periods presented:



	September 30, 2016							December 31, 2015
(dollars in thousands)	Gross Unrealized Gains		Gross Unrealized Losses			Net Unrealized Gains/ (Losses)		Gross Unrealized Gains		Gross Unrealized Losses			Net Unrealized Gains/ (Losses)
Total unrealized gains/(losses) on securities available-for-sale	$	21,938	$	(8	)	$	21,930	$	11,897	$	(1,716	)	$	10,181
Income tax expense/(benefit)	7,678		(3		)	7,675		4,164		(601		)	3,563
Net unrealized gains/(losses), net of tax included in accumulated other comprehensive income/(loss)	$	14,260	$	(5	)	$	14,255	$	7,733	$	(1,115	)	$	6,618

The amortized cost and fair value of securities available-for-sale at September 30, 2016 by contractual maturity are included in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.



	September 30, 2016
(dollars in thousands)	Amortized Cost		Fair Value
Obligations of the U.S. Treasury, U.S. government corporations and agencies, and obligations of states and political subdivisions
Due in one year or less	$	52,302	$	52,439
Due after one year through five years	216,729		222,114
Due after five years through ten years	55,893		58,699
Due after ten years	60,508		65,264
	385,432		398,516
Collateralized mortgage obligations of U.S. government corporations and agencies	134,675		137,460
Residential mortgage-backed securities of U.S. government corporations and agencies	34,685		36,285
Commercial mortgage-backed securities of U.S. government corporations and agencies	86,827		88,499
Debt Securities	641,619		660,760
Marketable equity securities	7,579		10,368
Total	$	649,198	$	671,128

At September 30, 2016 and December 31, 2015, securities with carrying values of $291.4 million and $278.4 million were pledged for various regulatory and legal requirements.