Goodwill and Identifiable Assets (Notes)

6 Months Ended

Jun. 30, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Identifiable Intangible Assets

4. Goodwill and Identifiable Intangible Assets

The changes in the carrying amount of goodwill by segment for the six months ended June 30, 2020 and the year ended December 31, 2019 were as follows (in millions):

	Apex			Oxford			ECS		Total
Balance as of December 31, 2018	$	662.1		$	230.8		$	528.2	$	1,421.1
DHA acquisition	—			—			24.7		24.7
Intersys acquisition	41.4			—			—		41.4
Translation adjustment	—			(0.3		)	—		(0.3		)
Balance as of December 31, 2019	703.5			230.5			552.9		1,486.9
Blackstone Federal acquisition	—			—			61.1		61.1
Translation adjustment	(0.5		)	(0.2		)	—		(0.7		)
Balance as of June 30, 2020	$	703.0		$	230.3		$	614.0	$	1,547.3

Acquired intangible assets consisted of the following (in millions):

		June 30, 2020						December 31, 2019
	Estimated Useful Life in Years	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Subject to amortization:
Customer and contractual relationships	2 - 12.75	$	403.6	$	200.4	$	203.2	$	384.9	$	179.9	$	205.0
Contractor relationships	2 - 5	71.1		70.7		0.4		71.1		70.6		0.5
Backlog	1 - 2.75	28.3		25.9		2.4		25.0		23.9		1.1
Non-compete agreements	2 - 7	25.6		15.9		9.7		24.8		13.8		11.0
In-use software	6	18.9		18.9		—		18.9		18.9		—
		547.5		331.8		215.7		524.7		307.1		217.6
Not subject to amortization:
Trademarks		258.9		—		258.9		258.9		—		258.9
Total		$	806.4	$	331.8	$	474.6	$	783.6	$	307.1	$	476.5

Estimated future amortization expense is as follows (in millions): 

Remainder of 2020	$	25.1
2021	41.0
2022	32.7
2023	28.0
2024	21.2
Thereafter	67.7
	$	215.7