Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The changes in goodwill by reportable segment are as follows:

	Corporate		Small Business		Public		Other(1)			Consolidated
Balances as of December 31, 2017(2)	$	1,074.1	$	185.9	$	929.6	$	290.0		$	2,479.6
Foreign currency translation	—		—		—		(16.8		)	(16.8		)
Balances as of December 31, 2018(2)	1,074.1		185.9		929.6		273.2			2,462.8
Scalar acquisition(3)	—		—		—		62.0			62.0
Other acquisition(4)	16.5		—		—		—			16.5
Foreign currency translation	—		—		—		11.7			11.7
Balances as of December 31, 2019(2)	$	1,090.6	$	185.9	$	929.6	$	346.9		$	2,553.0

(1) Other is comprised of CDW UK and CDW Canada reporting units.

(2) Goodwill is net of accumulated impairment losses of $1,571 million, $354 million and $28 million related to the Corporate, Public and Other segments, respectively.

(3) For additional information regarding the addition to goodwill resulting from the Company's acquisition, see Note 3 (Acquisition).

(4) The Company acquired Aptris, Inc. on October 1, 2019.

Schedule of Finite-Lived Intangible Assets

A summary of intangible assets is as follows:

December 31, 2019	Useful Lives (Years)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships and contracts	3 - 14	$	2,111.2	$	(1,786.4	)	$	324.8
Trade name	generally 20	422.8		(259.0		)	163.8
Internally developed software	3 - 5	263.5		(160.0		)	103.5
Other	1 - 10	5.5		(3.5		)	2.0
Total		$	2,803.0	$	(2,208.9	)	$	594.1
December 31, 2018
Customer relationships and contracts	3 - 14	$	2,071.0	$	(1,625.5	)	$	445.5
Trade name	generally 20	422.1		(237.3		)	184.8
Internally developed software	3 - 5	205.8		(125.4		)	80.4
Other	1 - 10	3.7		(2.2		)	1.5
Total		$	2,702.6	$	(1,990.4	)	$	712.2

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

Estimated future amortization expense related to intangible assets is as follows:

Years ending December 31,	Estimated Future Amortization Expense
2020	$	206.4
2021	110.4
2022	62.8
2023	41.3
2024	41.1
Thereafter	132.1
Total future amortization expense	$	594.1