Intangible Assets Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets

Intangible assets are summarized as follows (in thousands):

	Weighted Average Estimated Useful Life	December 31,
		2017			2016
Product technology	10 years	$	123,474		$	98,895
Customer relationships	11 years	73,382			87,013
Trademarks and trade name portfolios	13 years	9,606			8,160
Trade name portfolio not subject to amortization	indefinite	32,076			37,494
In-process research and development	7 years	5,602			4,700
Other	3 years	1,929			1,827
Acquired identifiable intangibles		246,069			238,089
Less accumulated amortization		(80,841		)	(73,535		)
Net acquired identifiable intangibles		165,228			164,554
Patents	7 years	6,112			6,083
Less accumulated amortization		(3,399		)	(2,531		)
Net patents		2,713			3,552
Acquired in-place leases and other	7 years	456			2,074
Less accumulated amortization		(267		)	(1,720		)
Net acquired in-place leases and other		189			354
		$	168,130		$	168,460

Estimated future aggregate amortization expense

For intangible assets recorded at December 31, 2017, the estimated future aggregate amortization expense for the years ending December 31, 2018 through 2022 is approximately (in thousands):

2018	$	23,949
2019	23,028
2020	20,132
2021	18,456
2022	18,119