Intangible Assets

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Intangible Assets

Intangible assets are summarized as follows (in thousands):

	Weighted Average Estimated Useful Life	December 31,
		2016			2015
Product technology	11 years	$	98,895		$	76,182
Customer relationships	11 years	87,013			69,272
Trademarks and trade name portfolios	14 years	8,160			7,540
Trade name portfolio not subject to amortization	indefinite	37,494			37,673
In-process research and development	n/a	4,700			2,250
Other	3 years	1,827			1,474
Acquired identifiable intangibles		238,089			194,391
Less accumulated amortization		(73,535		)	(58,173		)
Net acquired identifiable intangibles		164,554			136,218
Patents	7 years	6,083			6,104
Less accumulated amortization		(2,531		)	(1,671		)
Net patents		3,552			4,433
Acquired in-place leases and other	7 years	2,074			2,080
Less accumulated amortization		(1,720		)	(1,429		)
Net acquired in-place leases and other		354			651
		$	168,460		$	141,302

Note 8.        Intangible Assets - (Continued)

During the year ended December 31, 2016, the Company acquired $47.4 million of identifiable intangible assets as part of the acquisitions of Armasight and Point Grey and during the year ended December 31, 2015, the Company acquired $27.4 million of identifiable intangible assets as part of the acquisition of DVTEL, as described in Note 18, "Business Acquisitions."

The aggregate amortization expense recorded in 2016, 2015 and 2014 was $18.4 million, $16.4 million and $21.1 million, respectively. For intangible assets recorded at December 31, 2016, the estimated future aggregate amortization expense for the years ending December 31, 2017 through 2021 is approximately (in thousands):

2017	$	23,594
2018	19,962
2019	19,041
2020	16,095
2021	14,411