Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2014

Changes in Carrying Amount of Goodwill by Reporting Units

The changes in the carrying amount of goodwill by reportable segments for the years ended December 31, 2014 and 2013 are as follows:

	Semiconductor Test			System Test			Wireless Test			Total
	(in thousands)
Balance at December 31, 2012:
Goodwill	$	260,540		$	148,183		$	349,272		$	757,995
Accumulated impairment losses		(260,540	)		(148,183	)		—			(408,723	)
		—			—			349,272			349,272
ZTEC acquisition		—			—			12,520			12,520
Balance at December 31, 2013:
Goodwill		260,540			148,183			361,792			770,515
Accumulated impairment losses		(260,540	)		(148,183	)		—			(408,723	)
		—			—			361,792			361,792
ZTEC adjustment		—			—			27			27
AIT acquisition		—			10,516			—			10,516
Balance at December 31, 2014:
Goodwill		260,540			158,699			361,819			781,058
Accumulated impairment losses		(260,540	)		(148,183	)		(98,897	)		(507,620	)
	$	—		$	10,516		$	262,922		$	273,438

Schedule of Amortizable Intangible Assets

Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheets:

	December 31, 2014
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Weighted Average Useful Life
	(in thousands)
Developed technology	$	345,513	$	224,059	$	121,454		6.2 years
Customer relationships		146,635		93,998		52,637		7.7 years
Tradenames and trademarks		30,414		14,205		16,209		9.0 years
Non-competes		320		20		300		4.0 years
Customer backlog		170		170		—		0.0 years
Total intangible assets	$	523,052	$	332,452	$	190,600		6.8 years

	December 31, 2013
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Weighted Average Useful Life
	(in thousands)
Developed technology	$	342,933	$	174,563	$	168,370		6.2 years
Customer relationships		141,497		76,963		64,534		8.0 years
Tradenames and trademarks		30,034		10,647		19,387		9.1 years
Customer backlog		1,000		1,000		—		0.4 years
Total intangible assets	$	515,464	$	263,173	$	252,291		6.9 years

Schedule of Estimated Intangible Asset Amortization Expense

Estimated intangible assets amortization expense for each of the five succeeding fiscal years is as follows:

Year	Amortization Expense
	(in thousands)
2015	$	55,231
2016		55,231
2017		49,046
2018		24,405
2019		4,889