Intangible Assets Schedule of Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2015

The gross carrying amount and accumulated amortization of our intangible assets, other than goodwill, are as follows:



	December 31, 2015							December 31, 2014
	Gross Assets		Accumulated Amortization			Net		Gross Assets		Accumulated Amortization			Net
	(in thousands)
Core-developed technology	$	388,981	$	(358,092	)	$	30,889	$	405,434	$	(359,500	)	$	45,934
Customer contracts and relationships	238,379		(168,885		)	69,494		262,930		(172,755		)	90,175
Trademarks and trade names	64,069		(62,571		)	1,498		68,205		(64,905		)	3,300
Other	11,078		(11,027		)	51		11,579		(11,079		)	500
Total intangible assets	$	702,507	$	(600,575	)	$	101,932	$	748,148	$	(608,239	)	$	139,909

A summary of the intangible asset account activity is as follows:



	Year Ended December 31,
	2015			2014
	(in thousands)
Beginning balance, intangible assets, gross	$	748,148		$	804,281
Intangible assets acquired	4,827			1,453
Intangible assets impaired	(497		)	—
Effect of change in exchange rates	(49,971		)	(57,586		)
Ending balance, intangible assets, gross	$	702,507		$	748,148

The following table reflects our allocation of purchase price for intangible assets acquired on August 26, 2015:



	Fair Value		Weighted Average Useful Life
	(in thousands)		(in years)
Identified intangible assets
Core-developed technology	$	4,378	7.0
Customer contracts and relationships	337		7.0
Trademarks and trade names	56		3.0
Other	56		2.0
Total identified intangible assets subject to amortization	$	4,827	6.9

A summary of intangible asset amortization expense is as follows:

Estimated future annual amortization expense is as follows:



Year Ending December 31,	Estimated Annual Amortization
	(in thousands)
2016	$	25,240
2017	18,749
2018	13,068
2019	10,281
2020	8,388
Beyond 2020	26,206
Total intangible assets subject to amortization	$	101,932