11. Segment Reporting

The Company provides services through two operating segments, the Apex Segment and the Oxford Segment, with each addressing different sectors of the professional staffing and IT services market with distinct go-to-market strategies attuned to those sectors. Businesses in the Apex

Segment predominately serve markets with a large and local talent pool, and provide a full range of skills through a network of local offices where clients most value quality of talent relationship, speed, reliability and price. Businesses in the Oxford Segment predominately serve markets

with higher-end, specialized skills through a combination of national recruiting centers and local offices where clients most value the unique skill of the candidate and speed of response. The Apex Segment provides a broad spectrum of technical, digital, creative and scientific professionals for contract, contract-to-hire and permanent placement positions to Fortune 1000 and mid-market clients across the United States and Canada. The businesses in this segment include Apex Systems, Apex Life Sciences and Creative Circle. The Oxford Segment provides specialized staffing and permanent placement services in select skill and geographic markets. The businesses in this segment include Oxford, CyberCoders and Life Sciences Europe.

The Company’s management evaluates the performance of each segment primarily based on revenues, gross profit and operating income. The information in the following tables is derived directly from the segments’ internal financial reporting used for corporate management purposes. The Company's management does not evaluate, manage or measure performance of segments using asset information and such information is not readily available. Accordingly, assets by reportable segment are not disclosed.

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."

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

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	%