Business Segments (Tables)

12 Months Ended

Dec. 31, 2019

Revenue from External Customer [Line Items]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

The following tables present revenues, gross profit, operating income and amortization by reportable segment (in millions):

	Year ended December 31,
	2019			2018			2017
Apex:
Revenues	$	2,520.0		$	2,300.3		$	2,037.2
Gross profit	746.0			687.9			606.3
Operating income	287.7			262.4			222.0
Amortization	20.3			26.2			29.4
Oxford:
Revenues	$	605.7		$	606.5		$	588.8
Gross profit	242.9			248.9			243.8
Operating income	48.4			54.1			53.8
Amortization	3.7			4.2			4.0
ECS:
Revenues	$	798.2		$	493.0		$	—
Gross profit	141.1			86.9			—
Operating income	42.2			15.5			—
Amortization	27.1			28.1			—
Corporate:
Operating loss(1)	$	(69.7	)	$	(71.8	)	$	(51.1	)
Consolidated:
Revenues	$	3,923.9		$	3,399.8		$	2,626.0
Gross profit	1,130.0			1,023.7			850.1
Operating income	308.6			260.2			224.7
Amortization	51.1			58.5			33.4

_________

⁽¹⁾ Corporate expenses primarily consist of consolidated stock-based compensation expense, compensation for corporate employees, acquisition, integration and strategic planning expenses, public company expenses and depreciation expense for corporate assets.

Disaggregation of Revenue [Table Text Block]

The following table presents revenues by type (in millions):

	Year Ended December 31,
	2019		2018		2017
Apex:
Assignment	$	2,463.6	$	2,244.5	$	1,993.3
Permanent placement	56.4		55.8		43.9
	$	2,520.0	$	2,300.3	$	2,037.2
Oxford:
Assignment	$	522.7	$	516.0	$	503.1
Permanent placement	83.0		90.5		85.7
	$	605.7	$	606.5	$	588.8
ECS:
Firm-fixed-price	$	214.0	$	133.1	$	—
Time and Materials	267.8		143.4		—
Cost Reimbursable	316.4		216.5		—
	$	798.2	$	493.0	$	—
Consolidated	$	3,923.9	$	3,399.8	$	2,626.0

Revenue from External Customers by Products and Services [Table Text Block]

The following table presents the ECS segment revenues by customer type (in millions):

	Year Ended December 31,
	2019		2018
Department of Defense and Intelligence Agencies	$	453.9	$	311.0
Federal Civilian	293.6		150.9
Commercial and Other	50.7		31.1
	$	798.2	$	493.0

Revenue from External Customers by Geographic Areas [Table Text Block]

The Company operates internationally, with operations in the United States, Europe and Canada. The following table presents revenues by geographic location (in millions):

	Year Ended December 31,
	2019		2018		2017
Domestic	$	3,749.2	$	3,241.8	$	2,494.5
Foreign	174.7		158.0		131.5
	$	3,923.9	$	3,399.8	$	2,626.0

Reconciliation of Assets from Segment to Consolidated [Table Text Block]

The following table presents total assets by reportable segment (in millions):

	December 31,
	2019		2018
Apex	$	1,504.5	$	1,368.5
Oxford	433.8		421.2
ECS	935.2		865.6
Corporate(1)	67.9		32.5
	$	2,941.4	$	2,687.8

Long-lived Assets by Geographic Areas [Table Text Block]

The following table presents long-lived assets by geographic location (in millions):

	December 31,
	2019		2018
Domestic	$	71.4	$	76.7
Foreign	2.3		2.4
	$	73.7	$	79.1