11. Segment Reporting

On Assignment provides services through two operating segments with each addressing different sectors of the professional staffing market with distinct business models attuned to those sectors. The Apex Segment provides a broad spectrum of technical, scientific, digital and creative professionals for contract, contract-to-hire and permanent placement positions to Fortune 1000 and mid-market clients across the United States and Canada. Businesses in this segment include Apex Systems, Apex Life Sciences and Creative Circle. The Oxford Segment provides specialized staffing, permanent placement and consulting services in select skill and geographic markets. Businesses in this segment include Oxford Global Resources, 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 internal financial reports 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									Three Months Ended
	September 30, 2017									September 30, 2016
	Apex		Oxford		Corporate⁽¹⁾			Total		Apex		Oxford		Corporate⁽¹⁾			Total
Revenues	$	517,492	$	149,556	$	—		$	667,048	$	473,546	$	155,855	$	—		$	629,401
Gross profit	155,783		62,532		—			218,315		143,681		63,439		—			207,120
Operating income	59,016		16,088		(14,234		)	60,870		53,982		14,429		(13,001		)	55,410
Amortization	7,194		1,054		—			8,248		8,590		1,152		—			9,742



	Nine Months Ended									Nine Months Ended
	September 30, 2017									September 30, 2016
	Apex		Oxford		Corporate⁽¹⁾			Total		Apex		Oxford		Corporate⁽¹⁾			Total
Revenues	$	1,502,462	$	444,427	$	—		$	1,946,889	$	1,360,424	$	459,105	$	—		$	1,819,529
Gross profit	445,925		183,471		—			629,396		407,990		188,998		—			596,988
Operating income	162,679		39,525		(38,265		)	163,939		144,158		41,045		(41,332		)	143,871
Amortization	21,983		3,028		—			25,011		25,770		4,148		—			29,918


(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.

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



	Three Months Ended								Nine Months Ended
	September 30,								September 30,
	2017		%		2016		%		2017		%		2016		%
Revenues:
Assignment	$	634,339	95.1	%	$	596,437	94.8	%	$	1,848,868	95.0	%	$	1,720,312	94.5	%
Permanent placement	32,709		4.9	%	32,964		5.2	%	98,021		5.0	%	99,217		5.5	%
	$	667,048	100.0	%	$	629,401	100.0	%	$	1,946,889	100.0	%	$	1,819,529	100.0	%

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								Nine Months Ended
	September 30,								September 30,
	2017		%		2016		%		2017		%		2016		%
Revenues:
Domestic	$	632,584	94.8	%	$	599,991	95.3	%	$	1,849,567	95.0	%	$	1,732,594	95.2	%
Foreign	34,464		5.2	%	29,410		4.7	%	97,322		5.0	%	86,935		4.8	%
	$	667,048	100.0	%	$	629,401	100.0	%	$	1,946,889	100.0	%	$	1,819,529	100.0	%