Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The changes in the Company's goodwill consisted of the following:

(dollars in millions)	IT Services and Hardware			Network			Total Company
Goodwill, balance as of December 31, 2021	$	157.4		$	488.9		$	646.3
Activity during the year:
Adjustments to prior year Merger		2.5			2.2			4.7
Acquisition of Agile		—			39.4			39.4
Adjustments to postretirement and other benefit obligations (Note 11)		19.6			15.4			35.0
Currency translations		(1.9	)		—			(1.9	)
Goodwill, balance as of December 31, 2022		177.6			545.9			723.5
Activity during the year:
Adjustments to prior year acquisition of Agile		—			(4.4	)		(4.4	)
Acquisition of OTT		—			1.1			1.1
Currency translations		0.8			—			0.8
Goodwill, balance as of December 31, 2023	$	178.4		$	542.6		$	721.0

Schedule of Intangible Assets

The Company’s intangible assets consisted of the following:

	December 31, 2023							December 31, 2022
	Gross							Gross
	Carrying		Accumulated			Net		Carrying		Accumulated			Net
(dollars in millions)	Amount		Amortization			Amount		Amount		Amortization			Amount
Intangible assets subject to amortization
Customer relationships	$	863.5	$	(239.3	)	$	624.2	$	862.1	$	(140.7	)	$	721.4
Trade names		109.8		(36.2	)		73.6		109.5		(20.5	)		89.0
Technology		6.1		(1.9	)		4.2		6.0		(1.0	)		5.0
Total		979.4		(277.4	)		702.0		977.6		(162.2	)		815.4
Intangible assets not subject to amortization
FCC licenses and spectrum usage rights		7.1		—			7.1		6.9		—			6.9
Perpetual licenses		6.8		—			6.8		6.8		—			6.8
Total intangible assets	$	993.3	$	(277.4	)	$	715.9	$	991.3	$	(162.2	)	$	829.1

Schedule of Estimated Useful Lives for Finite-lived Intangible Assets

The estimated useful lives for each finite-lived intangible asset class are as follows:

Customer relationships	15 years
Trade names	3 to 10 years
Technology	7 years

Schedule of Estimated Amortization Expense

The annual estimated amortization expense for future years is as follows:

(dollars in millions)
Year ended December 31,
2024	$	105.6
2025		93.8
2026		86.6
2027		79.4
2028		72.0
Thereafter		264.6
Total	$	702.0