Goodwill and Other Intangible Assets

Changes in the carrying amount of goodwill by reportable segment are as follows:



(In thousands)	Fluids Systems			Mats and Integrated Services			Total
Balance at December 31, 2016	$	1,666		$	18,329		$	19,995
Acquisition	—			23,188			23,188
Effects of foreign currency	116			321			437
Balance at December 31, 2017	1,782			41,838			43,620
Acquisition	—			562			562
Effects of foreign currency	(141		)	(209		)	(350		)
Balance at December 31, 2018	$	1,641		$	42,191		$	43,832

We completed our annual evaluation of the carrying values of our goodwill and other indefinite-lived intangible assets as of November 1, 2018 and determined that the carrying values of each of our reporting units were less than their respective fair values and therefore, no impairment was required.

Other intangible assets consisted of the following:



	December 31, 2018							December 31, 2017
(In thousands)	Gross Carrying Amount		Accumulated Amortization			Other Intangible Assets, Net		Gross Carrying Amount		Accumulated Amortization			Other Intangible Assets, Net
Technology related	$	17,380	$	(5,509	)	$	11,871	$	15,596	$	(4,427	)	$	11,169
Customer related	40,662		(27,891		)	12,771		42,903		(24,679		)	18,224
Employment related	1,845		(1,845		)	—		1,864		(1,794		)	70
Total amortizing intangible assets	59,887		(35,245		)	24,642		60,363		(30,900		)	29,463

Permits and licenses	518		—			518		541		—			541
Total indefinite-lived intangible assets	518		—			518		541		—			541
Total intangible assets	$	60,405	$	(35,245	)	$	25,160	$	60,904	$	(30,900	)	$	30,004

Total amortization expense related to other intangible assets was $4.7 million, $3.3 million and $3.4 million in 2018, 2017 and 2016, respectively.

In November 2017, we completed the acquisition of WSG, and in August 2016, we completed the acquisition of Pragmatic, which resulted in additions to amortizable intangible assets of $27.0 million and $1.7 million, respectively. See Note 2 for additional information.

Estimated future amortization expense for the years ended December 31 is as follows:



(In thousands)	2019		2020		2021		2022		2023		Thereafter		Total
Technology related	$	1,140	$	1,112	$	1,061	$	1,002	$	836	$	6,720	$	11,871
Customer related	2,656		2,150		1,652		1,348		1,198		3,767		12,771
Total future amortization expense	$	3,796	$	3,262	$	2,713	$	2,350	$	2,034	$	10,487	$	24,642

The weighted average amortization period for technology related and customer related intangible assets is 15 years and 11 years, respectively.