Business Segments (Tables)

12 Months Ended

Dec. 31, 2018

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,
	2018			2017			2016
Net service revenues
Temporary and consultant staffing	$	4,330,566		$	4,011,042		$	4,026,777
Permanent placement staffing	511,989			439,214			419,314
Risk consulting and internal audit services	957,716			816,533			804,308
	$	5,800,271		$	5,266,789		$	5,250,399
Operating income
Temporary and consultant staffing	$	404,800		$	355,700		$	393,704
Permanent placement staffing	90,801			77,673			80,001
Risk consulting and internal audit services	93,324			83,907			80,754
	588,925			517,280			554,459
Amortization of intangible assets	1,705			1,563			1,237
Interest income, net	(4,382		)	(1,799		)	(888		)
Income before income taxes	$	591,602		$	517,516		$	554,110

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,
	2018		2017		2016
Net service revenues (a)
Domestic	$	4,433,767	$	4,121,701	$	4,220,477
Foreign (b)	1,366,504		1,145,088		1,029,922
	$	5,800,271	$	5,266,789	$	5,250,399
	December 31,
	2018		2017		2016
Assets, long-lived
Domestic	$	96,169	$	113,069	$	136,434
Foreign	29,007		31,818		25,075
	$	125,176	$	144,887	$	161,509

(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.