Goodwill and Identifiable Assets (Tables)

9 Months Ended

Sep. 30, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

The changes in the carrying amount of goodwill for the year ended December 31, 2014 and the nine months ended September 30, 2015 are as follows (in thousands):



	Apex Segment			Oxford Segment			Total
Balance as of December 31, 2013	$	289,712		$	224,714		$	514,426
Translation adjustment	(1,761		)	(605		)	(2,366		)
Balance as of December 31, 2014	287,951			224,109			512,060
Creative Circle Acquisition (See Note 3)	358,460			—			358,460
LabResource Acquisition (See Note 3)	—			6,104			6,104
Translation adjustment	(963		)	53			(910		)
Balance as of September 30, 2015	$	645,448		$	230,266		$	875,714

Schedule of Acquired Intangible Assets

cquired intangible assets consisted of the following (in thousands):



		As of September 30, 2015						As of December 31, 2014
	Estimated Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Intangible assets subject to amortization:
Customer relationships	2 - 10 years	$	197,230	$	67,934	$	129,296	$	101,141	$	53,434	$	47,707
Contractor relationships	2 - 5 years	69,806		37,314		32,492		39,332		32,021		7,311
Non-compete agreements	2 - 7 years	10,916		2,755		8,161		3,654		1,922		1,732
In-use software	6 years	18,900		5,729		13,171		18,900		3,366		15,534
Favorable contracts⁽¹⁾	5 years	900		97		803		—		—		—
		297,752		113,829		183,923		163,027		90,743		72,284
Intangible assets not subject to amortization:
Trademarks		245,698		—		245,698		178,325		—		178,325
Total		$	543,450	$	113,829	$	429,621	$	341,352	$	90,743	$	250,609

Schedule of Estimated Future Amortization Expense

Estimated amortization expense for the remainder of this year, each of the next four years, and thereafter is as follows (in thousands):



2015	$	11,373
2016	39,700
2017	33,068
2018	28,940
2019	22,039
Thereafter	48,803
	$	183,923