Intangible Assets

9 Months Ended

Sep. 30, 2019

Intangible Assets Net Excluding Goodwill [Abstract]

11. INTANGIBLE ASSETS

Intangible assets include those acquired in conjunction with several acquisitions since 2011, with the most recent being SmartRG, Inc. in November 2018.

The following table presents our intangible assets as of September 30, 2019 and December 31, 2018:

	September 30, 2019							December 31, 2018
(In thousands)	Gross Value		Accumulated Amortization			Net Value		Gross Value		Accumulated Amortization			Net Value
Customer relationships	$	22,235	$	(6,671	)	$	15,564	$	22,455	$	(5,380	)	$	17,075
Developed technology		10,170		(3,094	)		7,076		12,801		(4,867	)		7,934
Licensed technology		5,900		(1,011	)		4,889		5,900		(520	)		5,380
Supplier relationships		2,800		(2,158	)		642		2,800		(1,108	)		1,692
Licensing agreements		560		(61	)		499		560		(5	)		555
Patents		500		(209	)		291		500		(157	)		343
Trade names		310		(158	)		152		310		(106	)		204
Total	$	42,475	$	(13,362	)	$	29,113	$	45,326	$	(12,143	)	$	33,183

Amortization expense was $1.3 million and $0.9 million for the three months ended September 30, 2019 and 2018, respectively, and $4.0 million and $2.4 million for the nine months ended September 30, 2019 and 2018, respectively.

As of September 30, 2019, estimated future amortization expense of our intangible assets was as follows:

(In thousands)	Amount
Remainder of 2019	$	1,329
2020		4,436
2021		4,088
2022		3,464
2023		3,313
Thereafter		12,483
Total	$	29,113