Business Segments (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Reconciliation of Revenue and Operating Income by Reportable Segment to Consolidated Results

The following table provides a reconciliation of revenue and operating income by reportable segment to consolidated results (in thousands):

	Years Ended December 31,
	2017			2016			2015
Net service revenues
Temporary and consultant staffing	$	4,011,042		$	4,026,777		$	3,930,843
Permanent placement staffing	439,214			419,314			421,411
Risk consulting and internal audit services	816,533			804,308			742,679
	$	5,266,789		$	5,250,399		$	5,094,933
Operating income
Temporary and consultant staffing	$	355,700		$	393,704		$	399,808
Permanent placement staffing	77,673			80,001			85,019
Risk consulting and internal audit services	83,907			80,754			95,845
	517,280			554,459			580,672
Amortization of intangible assets	1,563			1,237			192
Interest income, net	(1,799		)	(888		)	(550		)
Income before income taxes	$	517,516		$	554,110		$	581,030

Revenue and Long-Lived Assets by Geographic Location

The following tables represent revenues and long-lived assets by geographic location (in thousands):

	Years Ended December 31,
	2017		2016		2015
Net service revenues (a)
Domestic	$	4,121,701	$	4,220,477	$	4,105,013
Foreign (b)	1,145,088		1,029,922		989,920
	$	5,266,789	$	5,250,399	$	5,094,933
	December 31,
	2017		2016		2015
Assets, long-lived
Domestic	$	113,069	$	136,434	$	117,176
Foreign	31,818		25,075		25,730
	$	144,887	$	161,509	$	142,906

(a) There were no customers that accounted for more than 10% of the Company’s total net revenue in any year presented.

(b) No individual country represented more than 10% of revenues in any year presented.