We assess goodwill, which is not amortized, for impairment annually during the fourth quarter, or more frequently, if events and circumstances indicate impairment may have occurred. We test goodwill for impairment at the reporting unit level. Goodwill is assigned to reporting units that are expected to benefit from the synergies of the business combination as of the acquisition date. Once goodwill has been allocated to the reporting units, it no longer retains its identification with a particular acquisition and becomes identified with the reporting unit in its entirety. Accordingly, the fair value of the reporting unit as a whole is available to support the recoverability of its goodwill. We evaluate our reporting units when changes in our operating structure occur, and if necessary, reassign goodwill using a relative fair value allocation approach.

Subsequent to our prior annual impairment test in the fourth quarter of 2018 the composition of our reportable segments has been revised, as discussed in “Note 15: Segment Information.” Prior to implementing the revised segment reporting structure in the first quarter of 2019, our previously disclosed Hotel segment was considered a single reporting unit. Following the change in reportable segments, our legacy Hotel reporting unit was split into four distinct reporting units – (1) Hotels, Media & Platform, (2) SmarterTravel, (3) Flights, Cruises and Car Rentals; and (4) TripAdvisor China for the purposes of goodwill impairment testing. As a result, we first performed a qualitative assessment on our previous Hotel reporting unit prior to implementing the revised segment reporting structure and determined that it was more likely than not that the fair value of this reporting unit was greater than the carrying value; which was consistent with our conclusion in the fourth quarter of 2018. We then performed a goodwill impairment test for each of the new reporting units upon the change in reportable segments using a quantitative assessment. We concluded the estimated fair values were significantly in excess of the carrying values for these 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 the first quarter of 2019.

Management exercised significant judgment related to the above assessment, including the identification of reporting units, reassignment of assets and liabilities to the new reporting units, reassignment of goodwill to the new reporting units using the relative fair value method, and determination of the fair value of new reporting units. The fair value of our reporting units are generally estimated using an equal weighting of a market approach by using public company multiples and/or other precedent transactions; and a discounted cash flow methodology. The discounted cash flows model indicates the fair value of the reporting units based on the present value of the cash flows that we expect the reporting units to generate in the future. This analysis requires significant judgment, including estimation of future cash flows, which is dependent on internal forecasts, the estimation of the long-term growth rate and profitability of the reporting unit, determination of the Company's weighted average cost of capital and income tax rates. Our significant estimates in the market approach model include identifying similar companies with comparable business factors such as size, growth, profitability, risk and return on investment and assessing comparable revenue and/or income multiples in estimating the fair value of the reporting units. Changes in these estimates and assumptions could materially affect the estimated fair value of the reporting unit, potentially resulting in a non-cash impairment charge.

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

	Hotel			Non-Hotel			Hotels, Media & Platform		Experiences & Dining			Other (3)			Total
	(in millions)						(in millions)
Balance as of December 31, 2018	$	451		$	305		$	-	$	-		$	-		$	756
Allocation to new segments (1)		(451	)		(305	)		405		250			101			-
Other adjustments (2)		-			-			-		(8	)		(2	)		(10	)
Balance as of September 30, 2019	$	-		$	-		$	405	$	242		$	99		$	746