Business Segments (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

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

	Year ended December 31, 2015
	Apex		Oxford		Corporate(1)			Total
Revenues	$	1,487,042	$	577,966	$	—		$	2,065,008
Gross Profit	437,507		241,238		—			678,745
Operating income	151,559		70,385		(69,836		)	152,108
Amortization	28,371		6,096		—			34,467

	Year ended December 31, 2014
	Apex		Oxford		Corporate(1)			Total
Revenues	$	1,190,052	$	534,689	$	—		$	1,724,741
Gross Profit	335,322		222,113		—			557,435
Operating income	121,334		70,193		(53,745		)	137,782
Amortization	16,356		5,765		9			22,130

	Year ended December 31, 2013
	Apex		Oxford		Corporate(1)			Total
Revenues	$	1,059,993	$	463,108	$	—		$	1,523,101
Gross Profit	294,611		160,264		—			454,875
Operating income	98,588		66,118		(48,119		)	116,587
Amortization	19,524		1,329		90			20,943

Revenue by Type [Table Text Block]

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

	Year Ended December 31,
	2015		2014		2013
Revenues:
Assignment	$	1,947,001	$	1,641,706	$	1,500,157
Permanent placement	118,007		83,035		22,944
	$	2,065,008	$	1,724,741	$	1,523,101

Disclosure on Geographic Areas, Description of Revenue from External Customers

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

	Year Ended December 31,
	2015		2014		2013
Revenues:
Domestic	$	1,972,888	$	1,643,598	$	1,446,805
Foreign	92,120		81,143		76,296
	$	2,065,008	$	1,724,741	$	1,523,101

Long Lived Assets By Geographic Location Domestic And Foreign

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

	December 31,
	2015		2014
Long-lived Assets:
Domestic	$	52,228	$	43,659
Foreign	968		652
	$	53,196	$	44,311