The carrying amount of goodwill, by operating segment is as follows:


(In thousands)	Domestic Operations		International		Total
December 31, 2023	$	348,732	$	277,764	$	626,496
Impairment charge	—		(68,004)		(68,004)


Foreign currency translation	—		708		708
September 30, 2024	$	348,732	$	210,468	$	559,200

As of September 30, 2024 and December 31, 2023, accumulated impairment charges in the International segment totaled $253.5 million and $185.5 million, respectively, inclusive of the 25/7 Media impairment charges recorded in 2023 prior to the divestiture of that business in December 2023.


(In thousands)	September 30, 2024
	Gross		Accumulated Amortization		Net		Estimated Useful Lives
Amortizable intangible assets:
Affiliate and customer relationships	$	622,236	$	(459,881)	$	162,355	6 to 25 years
Advertiser relationships	46,282		(46,282)		—		11 years
Trade names and other amortizable intangible assets	90,770		(46,267)		44,503		3 to 20 years

Total amortizable intangible assets	759,288		(552,430)		206,858
Indefinite-lived intangible assets:
Trademarks	19,900		—		19,900
Total intangible assets	$	779,188	$	(552,430)	$	226,758

(In thousands)	December 31, 2023
	Gross		Accumulated Amortization		Net
Amortizable intangible assets:
Affiliate and customer relationships	$	618,778	$	(421,968)	$	196,810
Advertiser relationships	46,282		(42,806)		3,476
Trade names and other amortizable intangible assets	91,134		(42,762)		48,372

Total amortizable intangible assets	756,194		(507,536)		248,658
Indefinite-lived intangible assets:
Trademarks	19,900		—		19,900
Total intangible assets	$	776,094	$	(507,536)	$	268,558

Aggregate amortization expense for amortizable intangible assets for the three months ended September 30, 2024 and 2023 was $7.9 million and $9.8 million, respectively, and for the nine months ended September 30, 2024 and 2023 was $26.1 million and $30.7 million, respectively.

Impairment and other charges of $96.8 million for the nine months ended September 30, 2024 primarily consisted of a $68.0 million goodwill impairment charge at AMCNI and $29.2 million of long-lived asset impairment charges at BBCA, both of which were recorded in the second quarter of 2024. Impairment and other charges of $30.3 million for the nine months ended September 30, 2023 consisted primarily of goodwill and long-lived asset impairment charges of $24.9 million at 25/7 Media.

Goodwill is not amortized, but instead is tested for impairment at the reporting unit annually as of December 1, or more frequently upon the occurrence of certain events or substantive changes in circumstances. During the second quarter of 2024, the Company determined that a triggering event had occurred with respect to the Company's decline in stock price. Accordingly, the Company performed quantitative assessments for all reporting units. The fair values were determined using a combination of an income approach, using a DCF model and a market comparables approach. The DCF model includes significant assumptions about revenue growth rates, long-term growth rates, and enterprise specific discount rates. Additionally, the market comparables approach uses guideline company valuation multiples. Given the uncertainty in determining assumptions underlying the DCF approach, actual results may differ from those used in the valuations. Based on the valuations performed, the Company concluded that the estimated fair value of the AMCNI reporting unit declined to less than its carrying amount. As a result, the Company recognized an impairment charge of $68.0 million related to the AMCNI reporting unit, included in Impairment and other charges in the condensed consolidated statements of income. No impairment charges were required for our other reporting unit.

Additionally during the second quarter of 2024, given continued market challenges and linear declines, the Company determined that sufficient indicators of potential impairment of long-lived assets existed at BBCA, and concluded that the carrying amount of the BBCA asset group was not recoverable. The carrying value of the BBCA asset group exceeded its fair value, and accordingly an impairment charge of $15.7 million was recorded for identifiable intangible assets and $13.5 million for other long-lived assets, which is included in Impairment and other charges in the condensed consolidated statements of income within the Domestic Operations operating segment. Fair values were determined using a market approach.

During the second quarter of 2023, and prior to its divestiture in December 2023, the Company revised its outlook for the 25/7 Media business, resulting in lower expected future cash flows. The Company performed a recoverability test and determined that the carrying amount of the 25/7 Media asset group was not recoverable. The carrying value of the asset group exceeded its fair value, therefore an impairment charge of $23.0 million was recorded for identifiable intangible assets, which is included in Impairment and other charges in the condensed consolidated statements of income within the International operating segment. Fair values used to determine the impairment charge were determined using an income approach, specifically a DCF model, and a market comparables approach.