9. Goodwill and Other Intangible Assets

Indefinite Lived Intangible Assets

As of December 31, 2018 and 2017 the carrying values of our indefinite lived intangible assets are as follows (in thousands):


	2018		2017
Goodwill	$	188,781	$	188,305
In-process R&D		9,382		13,954
Procurement contracts and agreements		2,013		2,013
Trademarks		844		841

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 these trademarks will contribute to our cash flows indefinitely.

As of December 31, 2018 and 2017 the value of our goodwill, all of which is related to our Medical Devices segment, is as follows (in thousands):



	2018		2017
Balance as of January 1,	$	188,305	$	78,294
Goodwill from JOTEC acquisition		5,100		110,100
Revaluation of goodwill denominated in foreign currency		(4,624)		(89)
Balance as of December 31,	$	188,781	$	188,305

Definite Lived Intangible Assets

As of December 31, 2018 and 2017 gross carrying values, accumulated amortization, and approximate amortization periods of our definite lived intangible assets are as follows (dollars in thousands):



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

	Gross Carrying		Accumulated		Amortization
December 31, 2017	Value		Amortization		Period
Acquired technology	$	139,045		8,685	11	–	22	Years
Patents		3,612		2,819			17	Years
Distribution and manufacturing rights and know-how		4,059		1,820	11	–	15	Years
Customer lists and relationships		32,419		3,552	13	–	22	Years
Other		1,439		1,076			3	Years

Amortization Expense

Amortization expense recorded in general, administrative, and marketing expenses on our Consolidated Statements of Operations and Comprehensive (Loss) Income for the years ended December 31 is as follows (in thousands):



	2018		2017		2016
Amortization expense	$	10,792	$	5,085	$	4,426

As of December 31, 2018 scheduled amortization of intangible assets for the next five years is as follows (in thousands):



	2019		2020		2021		2022		2023		Total
Amortization expense	$	10,394	$	10,228	$	10,203	$	9,657	$	9,244	$	49,726