Goodwill and Other Intangible Assets

The Company records as goodwill the excess of purchase price over the fair value of the identifiable net assets acquired. Impairment testing is performed annually, as well as when an event triggering impairment may have occurred. The Company performs its annual analysis as of June 30 each fiscal year. Accounting guidance permits preliminary assessment of qualitative factors to determine whether more substantial impairment testing is required. The Company chose to bypass the preliminary assessment and utilized a two-step process for impairment testing of goodwill. The first step tests for impairment, while the second step, if necessary, measures the impairment. No indicators of impairment were identified during the years ended December 31, 2018, 2017, or 2016.

Core deposit intangibles resulting from the MidCarolina acquisition in July 2011 were $6,556,000 and are being amortized on an accelerated basis over 108 months. Core deposit intangibles resulting from the MainStreet acquisition were $1,839,000 and are being amortized on an accelerated basis over 120 months.

The changes in the carrying amount of goodwill and intangibles for the twelve months ended December 31, 2018, are as follows (dollars in thousands):



	Goodwill		Intangibles
Balance at December 31, 2017	$	43,872	$	1,191
Amortization	—		(265		)
Balance at December 31, 2018	$	43,872	$	926

Goodwill and intangible assets at December 31, 2018 and 2017 are as follow (dollars in thousands):



	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
December 31, 2018
Core deposit intangibles	$	11,508	$	(10,582	)	$	926
Goodwill	43,872		—			43,872

December 31, 2017
Core deposit intangibles	$	11,508	$	(10,317	)	$	1,191
Goodwill	43,872		—			43,872

Amortization expense of core deposit intangibles for the years ended December 31, 2018, 2017, and 2016 was $265,000, $528,000, and $964,000, respectively. As of December 31, 2018, the estimated future amortization expense of core deposit intangibles is as follows (dollars in thousands):



Year	Amount
2019	$	219
2020	207
2021	197
2022	155
2023	127
2024 and after	21
Total	$	926