Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2013

Changes in Carrying Amount of Goodwill by Reporting Units

The changes in the carrying amount of goodwill by reporting units for the years ended December 31, 2013 and 2012 are as follows:

	Semiconductor Test			System Test			Wireless Test			Total
	(in thousands)
Balance at December 31, 2011:
Goodwill	$	260,540		$	148,183		$	352,778		$	761,501
Accumulated impairment losses		(260,540	)		(148,183	)		—			(408,723	)
		—			—			352,778			352,778
Activity during the year		—			—			(3,506	)		(3,506	)
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

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, 2013
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Weighted Average Useful Life
	(in thousands)
Developed technology	$	362,055	$	193,756	$	168,299		6.3 years
Customer relationships		146,341		81,742		64,599		8.0 years
Tradenames and trademarks		33,840		14,447		19,393		9.0 years
Customer backlog		1,000		1,000		—		0.4 years
Total intangible assets	$	543,236	$	290,945	$	252,291		7.0 years

	December 31, 2012
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Weighted Average Useful Life
	(in thousands)
Developed technology	$	357,555	$	143,126	$	214,429		6.3 years
Customer relationships		144,971		63,464		81,507		8.0 years
Tradenames and trademarks		33,840		10,909		22,931		9.0 years
Customer backlog		1,000		1,000		—		0.4 years
Total intangible assets	$	537,366	$	218,499	$	318,867		7.0 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)
2014	$	70,141
2015		53,391
2016		53,391
2017		47,232
2018		22,691