Intangible Assets

12 Months Ended

Dec. 31, 2020

Intangible Assets, Net (Excluding Goodwill) [Abstract]

The following table presents the major classes of the company's intangible assets at December 31, 2020 and 2019:


$ in millions	Gross Book Value	Accumulated Amortization	Net Book Value
December 31, 2020
Management contracts - indefinite-lived	6,982.7	N/A	6,982.7
Management contracts - finite-lived	319.9	(118.7)	201.2
Developed technology	99.2	(50.9)	48.3
Other	110.8	(37.4)	73.4
Total	7,512.6	(207.0)	7,305.6
December 31, 2019
Management contracts - indefinite-lived	6,969.1	N/A	6,969.1
Management contracts - finite-lived	319.3	(84.5)	234.8
Developed technology	98.6	(31.7)	66.9
Other	112.2	(24.7)	87.5
Total	7,499.2	(140.9)	7,358.3

There were no acquisitions during 2020 (2019: Invesco acquired $4,907.0 million in indefinite lived management contracts, $255.0 million of finite-lived intangible asset related management contracts and $27.0 million of trade name assets related to the Oppenheimer acquisition. Other 2019 additions to intangible assets related to the preliminary valuations of acquisitions of digital wealth technology companies. Amortizable intangible assets of $315.4 million related to 2019 acquisitions have a weighted-average amortization period of 7.15 years).

The 2020 and 2019 annual impairment reviews of indefinite-lived intangible assets determined that no impairment existed. Due to the decline in our assets under management in the three months ended March 31, 2020, management determined that an interim impairment test was necessary for certain of our indefinite-lived management contract assets during 2020. The analysis resulted in no impairment because the fair value of indefinite-lived intangible assets exceeded their carrying value. No interim impairment test was deemed necessary during 2019.

Amortization expense was $62.5 million during the year ended December 31, 2020 (December 31, 2019: $52.7 million; December 31, 2018: $29.7 million). Estimated amortization expense for each of the five succeeding fiscal years based upon the company's intangible assets at December 31, 2020 is as follows:


$ in millions Years Ended December 31,			Estimated Amortization Expense
2021			(62.8)
2022			(60.3)
2023			(52.0)
2024			(46.4)
2025			(39.2)