Segment Reporting (Tables)

6 Months Ended

Jun. 30, 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						Six Months Ended
	June 30,						June 30,
	2018			2017			2018			2017
Apex:
Revenues	$	567,507		$	502,455		$	1,106,011		$	984,970
Gross profit	169,667			150,223			328,315			290,142
Operating income	64,903			56,770			121,167			103,663
Amortization	6,546			7,262			13,092			14,789
Oxford:
Revenues	$	155,852		$	150,858		$	302,521		$	294,871
Gross profit	65,520			62,714			124,609			120,939
Operating income	14,812			14,774			24,638			23,437
Amortization	1,048			1,037			2,103			1,974
ECS:
Revenues	$	155,150		$	—		$	155,150		$	—
Gross profit	28,659			—			28,659			—
Operating income	3,698			—			3,698			—
Amortization	10,954			—			10,954			—
Corporate:
Operating income(1)	$	(17,731	)	$	(12,083	)	$	(38,129	)	$	(24,031	)
Consolidated:
Revenues	$	878,509		$	653,313		$	1,563,682		$	1,279,841
Gross profit	263,846			212,937			481,583			411,081
Operating income	65,682			59,461			111,374			103,069
Amortization	18,548			8,299			26,149			16,763

_____________

(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 our revenues disaggregated by type (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
Apex
Assignment	$	553,672	$	491,334	$	1,078,526	$	962,600
Permanent placement	13,835		11,121		27,485		22,370
	$	567,507	$	502,455	$	1,106,011	$	984,970
Oxford
Assignment	$	130,301	$	128,680	$	255,703	$	251,929
Permanent placement	25,551		22,178		46,818		42,942
	$	155,852	$	150,858	$	302,521	$	294,871
ECS
Firm-fixed-price	$	44,762	$	—	$	44,762	$	—
Time and materials	48,995		—		48,995		—
Cost-plus-fixed-fee	61,393		—		61,393		—
	$	155,150	$	—	$	155,150	$	—
Consolidated	$	878,509	$	653,313	$	1,563,682	$	1,279,841

Schedule of Revenue by Geographical Areas

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

	Three Months Ended								Six Months Ended
	June 30,								June 30,
	2018		%		2017		%		2018		%		2017		%
Revenues:
Domestic	$	837,972	95.4	%	$	620,682	95.0	%	$	1,485,239	95.0	%	$	1,216,983	95.1	%
Foreign	40,537		4.6	%	32,631		5.0	%	78,443		5.0	%	62,858		4.9	%
	$	878,509	100.0	%	$	653,313	100.0	%	$	1,563,682	100.0	%	$	1,279,841	100.0	%