Goodwill and Intangible Assets

3 Months Ended

Mar. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

6.   Goodwill and Intangible Assets. The changes in the carrying amount of goodwill for the three-month period ended March 31, 2020 were as follows (in thousands):

	2020
Goodwill balance at January 1	$	353,193
Effect of foreign exchange		(951)
Goodwill balance at March 31	$	352,242

Total accumulated goodwill impairment losses aggregated to approximately $8.3 million as of March 31, 2020 and December 31, 2019. We did not have any goodwill impairments for the three-month periods ended March 31, 2020 and 2019. The total goodwill balance as of March 31, 2020 and December 31, 2019 was related to our cardiovascular segment.

Other intangible assets at March 31, 2020 and December 31, 2019, consisted of the following (in thousands):

	March 31, 2020
	Gross Carrying		Accumulated		Net Carrying
	Amount		Amortization		Amount
Patents	$	23,764	$	(7,396)	$	16,368
Distribution agreements		5,754		(4,656)		1,098
License agreements		22,017		(8,337)		13,680
Trademarks		30,235		(10,202)		20,033
Customer lists		39,357		(29,343)		10,014
In-process technology		2,500		—		2,500
Total	$	123,627	$	(59,934)	$	63,693

	December 31, 2019
	Gross Carrying		Accumulated		Net Carrying
	Amount		Amortization		Amount
Patents	$	22,703	$	(6,863)	$	15,840
Distribution agreements		8,012		(6,794)		1,218
License agreements		26,987		(12,746)		14,241
Trademarks		30,240		(9,477)		20,763
Covenants not to compete		964		(964)		—
Customer lists		39,984		(28,763)		11,221
In-process technology		2,500		—		2,500
Total	$	131,390	$	(65,607)	$	65,783

Aggregate amortization expense for the three-month periods ended March 31, 2020 and 2019 was approximately $15.0 million and $14.8 million, respectively.

We evaluate long-lived assets, including amortizing intangible assets, for impairment whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. We perform the impairment analysis at the asset group for which the lowest level of identifiable cash flows is largely independent of the cash flows of other assets and liabilities. We compare the carrying value of the amortizing intangible assets acquired to the undiscounted cash flows expected to result from the asset group and determine whether the carrying amount is recoverable. We determine the fair value of our amortizing assets based on estimated future cash flows discounted back to their present value using a discount rate that reflects the risk profiles of the underlying activities. We did not identify indicators of impairment in any intangible assets based on our qualitative assessment for the three-month periods ended March 31, 2020 and 2019.

Estimated amortization expense for the developed technology and other intangible assets for the next five years consists of the following as of March 31, 2020 (in thousands):

Year Ending December 31,	Estimated Amortization Expense
Remaining 2020	$	44,365
2021		51,932
2022		50,625
2023		49,417
2024		46,465