The carrying amount of goodwill for each of the Company’s operating segments for the years ended December 31, 2019 and 2018 is as follows (in thousands):

	December 31,						December 31,										December 31,
	2017		Acquisition		Impairment		2018		Acquisition		Currency			Impairment			2019
Television	$	40,549		—		—	$	40,549		—		—			—		$	40,549
Radio		—		—		—		—		—		—			—			—
Digital		30,180		3,563		—		33,743		—		(67	)		(27,714	)		5,962
Consolidated	$	70,729	$	3,563	$	—	$	74,292	$	—	$	(67	)	$	(27,714	)	$	46,511

The composition of the Company’s acquired intangible assets and the associated accumulated amortization as of December 31, 2019 and 2018 is as follows (in thousands):

			2019						2018
	Weighted average remaining life in years		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Intangible assets subject to amortization:
Television network affiliation agreements		7	$	67,489	$	58,338	$	9,151	$	67,489	$	56,950	$	10,539
Customer base		4		10,045		6,414		3,631		10,045		5,044		5,001
Pre-sold advertising contracts and other		5		39,057		35,067		3,990		38,857		31,799		7,058
Total assets subject to amortization:			$	116,591	$	99,819	$	16,772	$	116,391	$	93,793	$	22,598
Intangible assets not subject to amortization:
FCC licenses and spectrum usage rights								252,544						254,598
Total intangible assets							$	269,316					$	277,196

The aggregate amount of amortization expense for the years ended December 31, 2019, 2018 and 2017 was approximately $6.0 million, $6.1 million and $5.9 million, respectively. Estimated amortization expense for the next five years and thereafter is as follows (in thousands):

The Company has identified each of its three operating segments to be separate reporting units: television broadcasting, radio broadcasting, and digital media. The carrying values of the reporting units are determined by allocating all applicable assets (including goodwill) and liabilities based upon the unit in which the assets are employed and to which the liabilities relate, considering the methodologies utilized to determine the fair value of the reporting units.

Goodwill and indefinite life intangibles are not amortized but are tested annually for impairment, or more frequently, if events or changes in circumstances indicate that the assets might be impaired. The annual testing date is October 1.

The Company conducted a review of the fair value of the television reporting unit. As of the annual goodwill testing date, October 1, 2019, there was $40.5 million of goodwill in the television reporting unit.

Based on the assumptions and estimates in Note 2 above, the television reporting unit fair value exceeded its carrying value by 38%, resulting in no impairment charge in 2019. The calculation of the fair value of the reporting unit requires estimates of the discount rate and the long term projected growth rate. If that discount rate were to increase by 0.5%, the fair value of the television reporting unit would decrease by 6%. If the long term projected growth rate were to decrease by 0.5%, the fair value of the television reporting unit would decrease by 5%.

Due to lower than anticipated performance of our digital reporting unit, changes in key personnel, and updated internal forecasts of future performance of our digital reporting unit, the Company determined that triggering events had occurred during each of the second and third quarters of 2019 that required interim impairment assessments for the digital reporting unit. As a result, the Company recorded impairment charges in the digital reporting unit of $22.4 million and $5.3 million in the second and third quarter of 2019, respectively, for a total goodwill impairment charge of $27.7 million for the year ended December 31, 2019.

Because we conducted an interim impairment assessment relating to our digital reporting unit in the third quarter of 2019, as of September 30, 2019, we did not conduct an impairment assessment in our digital reporting unit on the annual goodwill testing date of October 1, 2019. As of October 1, 2019, there was $6.0 million of goodwill in the digital media reporting unit.

The calculation of the fair value of the reporting unit requires estimates of the discount rate and the long term projected growth rate. If that discount rate were to increase by 1%, the fair value of the digital reporting unit would decrease by 8%. If the long term projected growth rate were to decrease by 0.5%, the fair value of the digital reporting unit would decrease by 2%.

Uncertain economic conditions, fiscal policy and other factors beyond the Company’s control potentially could have an adverse effect on the capital markets, which would affect the discount rate assumptions, terminal value estimates, transaction premiums and comparable transactions. Such uncertain economic conditions could also have an adverse effect on the fundamentals of the business and results of operations, which would affect the internal forecasts about future performance and terminal value estimates. Furthermore, such uncertain economic conditions could have a negative impact on the digital advertising industry in general or the industries of those customers who advertise with the digital reporting unit, including, among others, the automotive, financial and other services, telecommunications, travel and restaurant industries, which in the aggregate provide a significant amount of the historical and projected advertising revenue. The activities of competitors could have an adverse effect on the internal forecasts about future performance and terminal value estimates. Changes in technology or audience preferences, including increased competition from other forms of advertising-based mediums, could have an adverse effect on the internal forecasts about future performance, terminal value estimates and transaction premiums. Finally, the risk factors that the Company identifies from time to time in its SEC reports could have an adverse effect on the internal forecasts about future performance, terminal value estimates and transaction premiums.

There can be no assurance that the estimates and assumptions made for the purpose of the Company’s goodwill impairment testing will prove to be accurate predictions of the future. If the assumptions regarding internal forecasts of future performance of the reporting unit are not achieved, if market conditions change and affect the discount rate, or if there are lower comparable transactions and transaction premiums, the Company may be required to record goodwill impairment charges in future periods. It is not possible at this time to determine if any such future change in the Company’s assumptions would have an adverse impact on the valuation models and result in impairment, or if it does, whether such impairment charge would be material.

The Company did not have any goodwill in its radio reporting unit at December 31, 2019 and 2018.

The Company also conducted a review of the fair value of the television and radio FCC licenses in 2019 and 2018. The estimated fair value of indefinite life intangible assets is determined by an income approach. The income approach estimates fair value based on the estimated future cash flows of each market cluster that a hypothetical buyer would expect to generate, discounted by an estimated weighted-average cost of capital that reflects current market conditions, which reflect the level of inherent risk. The income approach requires the Company to make a series of assumptions, such as discount rates, revenue projections, profit margin projections and terminal value multiples. The Company estimates the discount rates on a blended rate of return considering both debt and equity for comparable publicly-traded companies. These comparable publicly-traded companies have similar size, operating characteristics and/or financial profiles to the Company. The Company also estimated the terminal value multiple based on comparable publicly-traded companies. The Company estimated the revenue projections and profit margin projections based on various market clusters signal coverage of the markets and industry information for an average station within a given market. The information for each market cluster includes such things as estimated market share, estimated capital start-up costs, population, household income, retail sales and other expenditures that would influence advertising expenditures. Alternatively, some stations under evaluation have had limited relevant cash flow history due to planned or actual conversion of format or upgrade of station signal. The assumptions the Company makes about cash flows after conversion are based on the performance of similar stations in similar markets and potential proceeds from the sale of the assets.

Based on the assumptions and estimates described above, the Company noted that the carrying values of one television FCC license and one radio FCC license exceeded their fair values. As a result, the Company recorded an impairment charge of FCC licenses in our television and radio reporting units in the amount of $0.5 million and $0.2 million, respectively, for the year ended December 31, 2019.

As a result of changes in regulations in Mexico, the Company was required to prepay the license fees for its Mexico broadcast licenses for a period of 20 years. The Company elected not to make the required prepayment for station XHRIO-TV serving the Matamoros/Harlingen-Weslaco-Brownsville-McAllen market before the deadline to make such prepayment. As a result, the Company currently expects to stop broadcasting on this station at the end of the current license term, which expires on December 31, 2021. As such, the Company determined that triggering events had occurred during the third quarter of 2019 that required an interim impairment assessment for this broadcast license. As a result of this assessment, the Company incurred an impairment charge related to indefinite life intangible assets in its television reporting unit in the amount of $3.5 million for the year ended December 31, 2019.

At the Company’s impairment testing date of October 1, 2019 and at December 31, 2019, the book value of net assets exceeded the market capitalization of the Company. During times of stock price volatility, significant judgment must be applied to determine whether stock price changes are a short term swing or a longer-term trend. The Company performed an annual test of its goodwill and indefinite life intangible assets as of October 1, 2019, and concluded that other than the goodwill impairment at the digital reporting unit discussed above the recorded values were not impaired based on the analysis. The key assumptions used in this analysis were: (a) the Company’s assets are still producing operating income and (b) the fair value of its existing assets, based on the Company’s analysis, remains sufficient to support the carrying value of the related assets including goodwill. There were no events that occurred subsequent to the annual impairment testing date that suggest that it is more likely than not that the fair value of any of the Company’s reporting units or indefinite life intangible assets are less than the respective carrying amounts.