Goodwill, Customer Relationships and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of goodwill, customer relationships and other intangible assets

Goodwill, customer relationships and other intangible assets consisted of the following:

	As of December 31,
	2020		2019
	(Dollars in millions)
Goodwill	$	9,360	9,360
Customer relationships, less accumulated amortization of $5,611 and $5,231	$	88	468
Other intangible assets, less accumulated amortization of $1,831 and $1,780	255		311
Total other intangible assets, net	$	343	779

Schedule of estimated amortization expense for intangible assets

We estimate that total amortization expense for intangible assets for the years ending December 31, 2021 through 2025 will be as follows:

	(Dollars in millions)
Year ending December 31,
2021	$	188
2022	99
2023	25
2024	9
2025	8