Goodwill and Identifiable Assets (Tables)

3 Months Ended

Mar. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

The changes in the carrying amount of goodwill for the three months ended March 31, 2020 and the year ended December 31, 2019 were as follows (in millions):



	Apex Segment			Oxford Segment			ECS Segment		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	(0.3		)	(0.7		)	—		(1.0		)
Balance as of March 31, 2020	$	703.2		$	229.8		$	614.0	$	1,547.0

Schedule of Acquired Intangible Assets

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



		March 31, 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	$	403.4	$	189.9	$	213.5	$	384.9	$	179.9	$	205.0
Contractor relationships	2 - 5	71.0		70.6		0.4		71.1		70.6		0.5
Backlog	1 - 2.75	28.3		24.8		3.5		25.0		23.9		1.1
Non-compete agreements	2 - 7	25.6		14.8		10.8		24.8		13.8		11.0
In-use software	6	18.9		18.9		—		18.9		18.9		—
		547.2		319.0		228.2		524.7		307.1		217.6
Not subject to amortization:
Trademarks		258.9		—		258.9		258.9		—		258.9
Total		$	806.1	$	319.0	$	487.1	$	783.6	$	307.1	$	476.5

Schedule of Estimated Future Amortization Expense

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



Remainder of 2020	$	37.7
2021	41.0
2022	32.6
2023	28.0
2024	21.2
Thereafter	67.7
	$	228.2