5. Goodwill and Other Intangible Assets

Indefinite Lived Intangible Assets

As of March 31, 2019 and December 31, 2018 the carrying values of our indefinite lived intangible assets were as follows (in thousands):


	March 31,		December 31,
	2019		2018
Goodwill	$	186,706	$	188,781
In-process R&D		9,206		9,382
Procurement contracts and agreements		2,013		2,013
Trademarks		844		844

We monitor the phases of development of our acquired in-process R&D projects, including the risks associated with further development and the amount and timing of benefits expected to be derived from the completed projects. Incremental costs associated with development are charged to expense as incurred. Capitalized costs are amortized over the estimated useful life of the developed asset once completed. Our in-process R&D projects are reviewed for impairment annually or more frequently if events or changes in circumstances indicate that the asset might be impaired.

Based on our experience with similar agreements, we believe that our acquired procurement contracts and agreements have indefinite useful lives, as we expect to continue to renew these contracts for the foreseeable future. We believe that our trademarks have indefinite useful lives as we currently anticipate that our trademarks will contribute to our cash flows indefinitely.

As of March 31, 2019 and December 31, 2018 our entire goodwill balance was related to our Medical Devices segment.


	Medical Devices Segment
Balance as of December 31, 2018	$	188,781
Revaluation of goodwill denominated in foreign currency		(2,075)
Balance as of March 31, 2019	$	186,706

Definite Lived Intangible Assets

As of March 31, 2019 and December 31, 2018 the gross carrying values, accumulated amortization, and approximate amortization period of our definite lived intangible assets were as follows (in thousands):


	Gross Carrying		Accumulated		Amortization
March 31, 2019	Value		Amortization		Period
Acquired technology	$	133,187	$	18,708	11	–	22	Years
Customer lists and relationships		31,131		5,444	13	–	22	Years
Distribution and manufacturing rights and know-how		4,059		2,179	11	–	15	Years
Patents		3,622		2,979			17	Years
Other		1,350		290	3	–	5	Years

	Gross Carrying		Accumulated		Amortization
December 31, 2018	Value		Amortization		Period
Acquired technology	$	134,999	$	16,815	11	–	22	Years
Customer lists and relationships		31,169		5,068	13	–	22	Years
Distribution and manufacturing rights and know-how		4,059		2,107	11	–	15	Years
Patents		3,656		2,970			17	Years
Other		1,154		235	3	–	5	Years

Amortization Expense

The following is a summary of amortization expense as recorded in general, administrative, and marketing expenses on our Summary Consolidated Statement of Operations and Comprehensive (Loss) Income (in thousands):


	Three Months Ended
	March 31,
	2019		2018
Amortization expense	$	2,579	$	2,735

As of March 31, 2019 scheduled amortization of intangible assets for the next five years is as follows (in thousands):


	Remainder
	of 2019		2020		2021		2022		2023		2024		Total
Amortization expense	$	7,727	$	10,151	$	10,129	$	9,583	$	9,173	$	8,948	$	55,711