Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2018

Segment Reporting Information [Line Items]

Schedule of Segment Reporting Information, by Segment

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



	Three Months Ended
	March 31, 2018
	Apex		Oxford		Corporate⁽¹⁾			Total
Revenues	$	538,504	$	146,669	$	—		$	685,173
Gross profit	158,648		59,089		—			217,737
Operating income	56,264		9,826		(20,398		)	45,692
Amortization	6,546		1,055		—			7,601



	Three Months Ended
	March 31, 2017
	Apex		Oxford		Corporate⁽¹⁾			Total
Revenues	$	482,515	$	144,013	$	—		$	626,528
Gross profit	139,919		58,225		—			198,144
Operating income	46,893		8,663		(11,948		)	43,608
Amortization	7,527		937		—			8,464

(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. Corporate expenses for the three months ended March 31, 2018 included $9.8 million of one-time expenses related to the acquisition of ECS Federal, LLC, which closed on April 2, 2018, see "Note 12. Subsequent Events."

Disaggregation of Revenue [Table Text Block]

The following table presents our revenues disaggregated by type (in thousands):



	Three Months Ended						Three Months Ended
	March 31, 2018						March 31, 2017
	Apex		Oxford		Total		Apex		Oxford		Total
Revenues:
Assignment	$	524,854	$	125,402	$	650,256	$	471,266	$	123,249	$	594,515
Permanent placement	13,650		21,267		34,917		11,249		20,764		32,013
	$	538,504	$	146,669	$	685,173	$	482,515	$	144,013	$	626,528

Schedule of Revenue by Geographical Areas

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



	Three Months Ended
	March 31,
	2018		%		2017		%
Revenues:
Domestic	$	647,267	94.5	%	$	596,301	95.2	%
Foreign	37,906		5.5	%	30,227		4.8	%
	$	685,173	100.0	%	$	626,528	100.0	%