Goodwill and Intangible Assets, Net

Goodwill

Changes in the carrying amount of goodwill were as follows:



(In thousands)
Balance at December 31, 2018	$	48,485
Foreign exchange effects	(81		)
Balance at September 30, 2019	$	48,404

Intangible Assets, Net

The components of intangible assets, net were as follows:



	September 30, 2019							December 31, 2018
(In thousands)	Gross ⁽¹⁾		Accumulated Amortization ⁽¹⁾			Net		Gross ⁽¹⁾		Accumulated Amortization ⁽¹⁾			Net
Distribution rights	$	314	$	(198	)	$	116	$	329	$	(188	)	$	141
Patents	15,606		(6,253		)	9,353		14,560		(5,704		)	8,856
Trademarks and trade names	2,786		(2,129		)	657		2,786		(1,900		)	886
Developed and core technology	12,560		(9,597		)	2,963		12,560		(8,087		)	4,473
Capitalized software development costs	—		—			—		155		—			155
Customer relationships	32,683		(25,285		)	7,398		32,534		(22,675		)	9,859
Total intangible assets, net	$	63,949	$	(43,462	)	$	20,487	$	62,924	$	(38,554	)	$	24,370


⁽¹⁾	This table excludes the gross value of fully amortized intangible assets totaling $7.3 million and $7.1 million at September 30, 2019 and December 31, 2018, respectively.

Amortization expense is recorded in selling, general and administrative expenses, except amortization expense related to capitalized software development costs, which is recorded in cost of sales. Amortization expense by statement of operations caption was as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
(In thousands)	2019		2018		2019		2018
Cost of sales	$	—	$	18	$	—	$	91
Selling, general and administrative expenses	1,798		1,770		5,382		5,275
Total amortization expense	$	1,798	$	1,788	$	5,382	$	5,366

Estimated future annual amortization expense related to our intangible assets at September 30, 2019, was as follows:



(In thousands)
2019 (remaining 3 months)	$	1,791
2020	6,045
2021	2,555
2022	2,443
2023	2,298
Thereafter	5,355
Total	$	20,487