The Company reorganized its reporting units pursuant to an internal restructuring during the second quarter of 2020. Following the internal restructuring changes, our legacy Dining and Flights/Cruises/Car reporting units were reorganized into four new distinct reporting units: (1) TheFork, (2) Tripadvisor Restaurants, (3) Flights & Car; and (4) Cruises, for the purposes of goodwill impairment testing. As a result, we first performed a qualitative assessment

on our historical Dining and Flights/Cruise/Car reporting units prior to implementing the revised reporting unit structure and determined that it was more likely than not that the fair value of these reporting units was greater than the carrying value; which was consistent with our conclusion of our annual impairment test for 2019. We then performed a goodwill impairment test for each of the new reporting units using a quantitative assessment. We concluded the estimated fair values were in excess of the carrying values for each of the four new reporting units. We also performed sensitivity analyses, such as calculating estimated fair values using different rates for the weighted-average cost of capital and long-term rates of growth in the income approach and different revenue/income multiples in our market approach and the estimated fair values remained in excess of the carrying values. Therefore, no indications of impairment were identified as a result of these changes in our reporting units as of June 30, 2020. In addition, as a result of internal restructuring and the sale of the SmarterTravel business during the second quarter of 2020, our SmarterTravel reporting unit no longer exists. The sale of this business was not a significant disposition. This change in reporting units had no impact on the composition of our operating segments, or the information that our chief operating decision maker or CODM reviews to evaluate the financial performance of the Company’s operating segments.

During the third quarter of 2020, the Company recognized a goodwill impairment charge of $3 million, which represented all of the goodwill allocated to our Tripadvisor China reporting unit. This impairment was driven by strategic operating decisions made by the Company in the third quarter of 2020. Consequently, Tripadvisor China was no longer considered a reporting unit as of December 31, 2020.

During the Company's annual goodwill impairment test during the fourth quarter of 2020, a qualitative assessment was performed for all our reporting units. We determined that the fair value of all our remaining reporting units were in excess of their carrying values, and, accordingly, no further impairment charges were recorded during the year ending December 31, 2020.

Although our annual impairment testing did not result in any impairment indicators, due to the COVID-19 environment and our inability to predict the expected duration and ultimate severity of the impact of COVID-19, we believe our reporting units are at an elevated risk of impairment in future periods. We will continue to monitor our financial performance, stock price and other events and circumstances that may negatively impact the estimated fair values of our reporting units to determine if future impairment assessments may be necessary. A continued and prolonged duration, and/or decline in the outlook for future revenue and cash flows or other factors, related to COVID-19 or other events, could result in a determination that a non-cash impairment adjustment is required, which could be material.

The following table summarizes our goodwill activity by reportable segment for the periods presented:

	Hotel			Non-Hotel			Hotels, Media & Platform		Experiences & Dining			Other (7)			Total
	(in millions)						(in millions)
Balance as of December 31, 2018	$	451		$	305		$	—	$	—		$	—		$	756
Allocation to new segments (1)		(451	)		(305	)		405		250			101			—
Acquisitions (2)		—			—			—		85			—			85
Foreign currency translation adjustments		—			—			—		(2	)		1			(1	)
Balance as of December 31, 2019	$	—		$	—		$	405	$	333		$	102		$	840
Re-allocation of goodwill (3)								2		—			(2	)		—
Impairment (4)								—		—			(3	)		(3	)
Disposition (5)								—		—			(6	)		(6	)
Foreign currency translation adjustments								—		21			2			23
Other adjustments (6)								—		8			—			8
Balance as of December 31, 2020							$	407	$	362		$	93		$	862

There were no goodwill impairment charges recognized to our consolidated statements of operations during the years ended December 31, 2019 and 2018. As of December 31, 2020, accumulated goodwill impairment losses totaled $3 million, which was associated with Other.

Intangible assets, which were acquired in business combinations and recorded at fair value on the date of purchase, consist of the following for the periods presented:

	December 31,
		2020			2019
	(in millions)
Intangible assets with definite lives	$	262		$	253
Less: accumulated amortization		(206	)		(173	)
Intangible assets with definite lives, net		56			80
Intangible assets with indefinite lives		30			30
Total	$	86		$	110

Amortization expense for definite-lived intangible assets was $26 million, $33 million, and $34 million, for the years ended December 31, 2020, 2019 and 2018, respectively.

Our indefinite-lived intangible assets relate to trade names and trademarks. During the Company's annual indefinite-lived intangible impairment test during the fourth quarter of 2020, a qualitative assessment was performed. As part of our qualitative assessment we considered, amongst other factors, the amount of excess fair value of our trade names and trademarks to the carrying value of those same assets, changes in estimates, and

valuation input assumptions, since our previous quantitative analysis. After considering these factors and the impact that changes in such factors would have on the inputs used in our previous quantitative assessment, we determined that it was more likely than not that our indefinite-lived intangible assets were not impaired as of December 31, 2020.

There were no impairment charges recognized to our consolidated statement of operations during the years ended December 31, 2020, 2019 and 2018 related to our intangible assets.

The following table presents the components of our intangible assets with definite lives for the periods presented:

			December 31, 2020							December 31, 2019
	Weighted Average		Gross					Net		Gross					Net
	Remaining Life		Carrying		Accumulated			Carrying		Carrying		Accumulated			Carrying
	(in years)		Amount		Amortization			Amount		Amount		Amortization			Amount
			(in millions)							(in millions)
Trade names and trademarks		3.6	$	59	$	(41	)	$	18	$	59	$	(35	)	$	24
Customer lists and supplier relationships		4.5		104		(83	)		21		98		(65	)		33
Subscriber relationships		2.7		42		(35	)		7		40		(29	)		11
Technology and other		4.2		57		(47	)		10		56		(44	)		12
Total		3.9	$	262	$	(206	)	$	56	$	253	$	(173	)	$	80

Refer to “Note 3: Acquisitions and Other Investments” above for a discussion of definite lived intangible assets acquired in business combinations during the years ended December 31, 2020, 2019 and 2018.

Our definite-lived intangible assets are being amortized on a straight-line basis. The straight-line method of amortization is currently our best estimate, or approximates to date, the distribution of the economic use of these intangible assets.

The estimated amortization expense for intangible assets with definite lives for each of the next five years, and the expense thereafter, assuming no subsequent impairment of the underlying assets or change in estimate of remaining lives, is expected to be as follows (in millions):