15. Goodwill and Acquired Intangible Assets

As of September 30, 2019, the carrying amount of goodwill was $9.0 million. The following is a rollforward of the Company’s goodwill balance (in thousands):


	Goodwill
Balance as of December 31, 2018	$	1,308
Goodwill acquired		8,111
Cumulative translation adjustment		(458)
Balance as of September 30, 2019	$	8,961

Acquired intangible assets as of September 30, 2019 consist of the following (in thousands):


		September 30, 2019
		Gross				Cumulative		Net
	Estimated Useful	Carrying		Accumulated		Translation		Carrying
	Life (in years)	Value		Amortization		Adjustment		Value
Know-how	8.5	$	13,000	$	(383)	$	(711)	$	11,906
Developed technology	7		1,650		(648)		—		1,002
Customer relationships	8.5 - 10		1,360		(368)		(6)		986
Non-compete agreements	5.5		340		(17)		(18)		305
Trade names	3		50		(28)		—		22
Total		$	16,400	$	(1,444)	$	(735)	$	14,221

Acquired intangible assets as of December 31, 2018 consist of the following (in thousands):


		December 31, 2018
		Gross				Cumulative		Net
	Estimated Useful	Carrying		Accumulated		Translation		Carrying
	Life (in years)	Value		Amortization		Adjustment		Value
Developed technology	7	$	1,650	$	(379)	$	—	$	1,271
Customer relationships	10		1,250		(208)		—		1,042
Trade names	3		50		(15)		—		35
Total		$	2,950	$	(602)	$	—	$	2,348

The Company acquired $13.5 million of intangible assets in the Uman acquisition, of which $13.0 million was assigned to know-how, $0.4 million was assigned to non-compete agreements, and $0.1 million was assigned to customer relationships. The know-how and customer relationships intangible assets are being amortized on a straight-line basis over an 8.5 year amortization period, and the non-compete agreement intangible asset is being amortized on a straight-line basis over a 5.5 year amortization period. In total, the weighted-average amortization period for these intangible assets is 8.4 years.

The Company is currently evaluating the fair value of assets acquired and liabilities assumed from the Uman acquisition, including intangible assets and their related amortization periods. As such, the $13.5 million in intangible assets presented in the table above are provisional and will be finalized in a later period once the fair value procedures are completed.

The Company recorded amortization expense of $0.5 million and $0.8 million for the three and nine months ended September 30, 2019, respectively, and $0.2 million and $0.4 million for the three and nine months ended September 30, 2018, respectively. Amortization relating to developed technology is recorded within research and development expenses, amortization of customer relationships is recorded within selling, general, and administrative expenses, amortization of trade names is recorded within selling, general and administrative expenses, amortization of non-compete agreements is recorded within selling, general, and administrative expenses, and amortization of know-how is recorded within cost of goods sold.

Future estimated amortization expense of acquired intangible assets as of September 30, 2019 is as follows (in thousands):


For the Years Ended December 31,	Estimated Amortization Expense
2019	$	546
2020		2,110
2021		2,013
2022		1,930
2023		1,849
Thereafter		6,508
	$	14,956