Goodwill and intangible assets are primarily the result of business acquisitions.

The Company performs its annual impairment assessment of goodwill and indefinite life intangible assets as of November 30 of each year.

No impairments to goodwill or indefinite life intangible assets were recorded during the three and six months ended June 30, 2024.

In May 2023, the Company's China reporting unit experienced adverse impacts as a result of changes in market conditions and increases in interest rates which contributed to reduced forecasted revenues and reduced projected future cash flows. As a result of these adverse impacts, the Company performed an interim quantitative assessment of goodwill impairment by comparing the fair value of its China reporting unit to its carrying value, including goodwill. When performing the assessment, the Company determined the fair value of its China reporting unit based on forecasted future cash flows. Based on the Company's forecast of the future cash flows of its China reporting unit, it was determined the carrying value of goodwill for its China reporting unit was impaired and the Company recorded a goodwill impairment charge of $77.4 million.

When performing the quantitative impairment assessment, the Company used a quantitative approach to measure the fair value of its China reporting unit using a discounted cash flow approach, which is a Level 3 measurement. The discounted cash flow analysis requires significant judgments, including estimates of future cash flows, which are dependent on internal forecasts and determination of the Company’s weighted average cost of capital, which is risk-adjusted to reflect the specific risk profile of the reporting unit being tested. The weighted average cost of capital used for the China reporting unit in the Company’s analysis was 12.5%.

As of November 30, 2023, the Company performed a qualitative assessment for its remaining reporting unit with goodwill and its trademark indefinite life intangible assets. The Company determined there were no indicators of impairment and that it was more likely than not that the fair value of the reporting unit and trademarks were greater than their carrying values and therefore performing the next step of the impairment test was unnecessary.

The accumulated impairment loss as of December 31, 2023 was due to the impairment charge discussed above of $77.4 million and an impairment charge of $25.8 million recognized during the year ended December 31, 2019.

There were no changes in the carrying amount of goodwill during the three and six months ended June 30, 2024.

Intangible Assets—No intangible asset impairments were recorded during the three and six months ended June 30, 2024.

During the three months ended June 30, 2023, the Company recorded an impairment charge to its China reporting unit's customer relationships and acquired technologies intangible assets. The Company's forecast of the revenue and expense cash flow of the China reporting unit indicated the carrying amounts of the intangible assets were not recoverable and therefore the Company recorded an impairment charge of $5.3 million.

The intangible assets balance as of June 30, 2024 is reflected below (in thousands):


		Weighted-
		Average
	Estimated	Remaining		Gross					Net
	Useful Life	Useful Life		Carrying		Accumulated			Carrying
	(Years)	(Years)		Amount		Amortization			Amount
Customer relationships	18		10.8	$	1,291,830	$	(514,938	)	$	776,892
Acquired technologies	7		4.6		184,640		(181,497	)		3,143
Subtotal					1,476,470		(696,435	)		780,035
Trademarks—indefinite life					190,470		—			190,470
Total intangible assets				$	1,666,940	$	(696,435	)	$	970,505

The intangible assets balance as of December 31, 2023 is reflected below (in thousands):


		Weighted-
		Average
	Estimated	Remaining		Gross					Net
	Useful Life	Useful Life		Carrying		Accumulated			Carrying
	(Years)	(Years)		Amount		Amortization			Amount
Customer relationships	16–18		11.3	$	1,291,830	$	(479,054	)	$	812,776
Acquired technologies	3–7		1.7		184,640		(172,840	)		11,800
Subtotal					1,476,470		(651,894	)		824,576
Trademarks—indefinite life					190,470		—			190,470
Total intangible assets				$	1,666,940	$	(651,894	)	$	1,015,046

Amortization expense for intangible assets was $20.0 million and $24.7 million for the three months ended June 30, 2024 and 2023, respectively. Amortization expense for intangible assets was $44.5 million and $49.4 million for the six months ended June 30, 2024 and 2023, respectively.