Intangible Assets

Intangible assets as of September 30, 2017 and December 31, 2016 consist of the following (in thousands, except the weighted-average amortization period):



	September 30, 2017
	Weighted-Average Amortization Period (in months)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Developed technologies	60	$	15,077	$	(9,616	)	$	5,461
Customer lists	47	9,970		(5,138		)	4,832
Trade names	47	5,513		(3,077		)	2,436
Non-compete agreements	30	1,728		(1,458		)	270
Master service agreements	21	1,030		(1,030		)	—
Indefinite-lived trade name	—	3,600		—			3,600
Total intangible assets		$	36,918	$	(20,319	)	$	16,599



	December 31, 2016
	Weighted-Average Amortization Period (in months)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Developed technologies	60	$	15,077	$	(8,245	)	$	6,832
Customer lists	47	9,970		(3,673		)	6,297
Trade names	47	5,513		(1,998		)	3,515
Non-compete agreements	30	1,728		(1,249		)	479
Master service agreements	21	1,030		(1,005		)	25
Indefinite-lived trade name	—	3,600		—			3,600
Total intangible assets		$	36,918	$	(16,170	)	$	20,748

During the three and nine months ended September 30, 2017, amortization expense related to our acquired intangible assets totaled approximately $1.4 million and $4.1 million, respectively. During the three and nine months ended September 30, 2016, amortization expense related to our acquired intangible assets totaled approximately $1.4 million and $3.2 million, respectively.

As of September 30, 2017, the estimated future amortization expense related to our finite-lived intangible assets is as follows (in thousands):



Remaining three months of 2017	$	1,201
2018	4,446
2019	3,510
2020	2,153
2021	815
Thereafter	874
Total	$	12,999