Changes in the carrying amount of goodwill were as follows:


(in thousands)	Total
Balance at December 31, 2022	$	1,011,429
Additions from acquisitions	164,502
Effects of movements in foreign exchange rates	704
Balance at December 31, 2023	1,176,635
Additions from acquisitions	26,948
Effects of movements in foreign exchange rates	(2,230)
Balance at December 31, 2024	$	1,201,353

The Company conducted its annual impairment test of goodwill as of October 1, 2024 and determined that there was no impairment of goodwill identified. Accumulated historical goodwill impairment losses were $792.8 million prior to Double Eagle Acquisition Corporation's acquisition of Williams Scotsman International, Inc. in 2017. There were no goodwill impairments recorded for the years ended December 31, 2024, 2023 and 2022.


	December 31, 2024
(in thousands)	Weighted average remaining life (in years)	Gross carrying amount		Impairment Loss		Accumulated amortization		Net book value
Intangible assets subject to amortization:
Customer relationships	3.5	$	215,408	$	—	$	(113,415)	$	101,993
Technology	1.5	1,500		—		(1,125)		375
Trade names	2.7	165,500		(132,540)		(9,164)		23,796
Indefinite-lived intangible assets:
Trade name – WillScot		125,000		—		—		125,000
Total intangible assets other than goodwill		$	507,408	$	(132,540)	$	(123,704)	$	251,164


	December 31, 2023
(in thousands)	Weighted average remaining life (in years)	Gross carrying amount		Accumulated amortization		Net book value
Intangible assets subject to amortization:
Customer relationships	4.5	$	214,408	$	(84,324)	$	130,084
Technology	2.5	1,500		(875)		625
Indefinite-lived intangible assets:
Trade name - Mobile Mini		164,000		—		164,000
Trade name - WillScot		125,000		—		125,000
Total intangible assets other than goodwill		$	504,908	$	(85,199)	$	419,709

For the years ended December 31, 2024, 2023 and 2022, the aggregate amount recorded to depreciation and amortization expense for intangible assets subject to amortization was $38.5 million, $25.8 million and $23.8 million, respectively.

In the second quarter of 2024, the Company determined that a review of the carrying value of the Mobile Mini trade name was necessary based on the Company's plan to rebrand under a single WillScot brand name and discontinue the use of the Mobile Mini trade name. As of June 30, 2024, the Mobile Mini trade name was tested for impairment using the relief from royalty valuation method. The estimate of fair value included a discount rate of 9%, an unobservable input (Level 3). After determining the estimated fair value, the Company recorded an impairment charge of $132.5 million during the year ended December 31, 2024. This non-cash charge was recorded to impairment loss on intangible asset on the consolidated statement of operations. After the impairment charge, the remaining net book value of the Mobile Mini trade name was $31.5 million, which is being amortized over the remaining useful life of the asset.