Intangible Assets Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets

Intangible assets are summarized as follows (in thousands):

	Weighted Average Estimated Useful Life	December 31,
		2018			2017
Product technology	10 years	$	117,563		$	123,474
Customer relationships	11 years	73,260			73,382
Trademarks and trade name portfolios	12 years	7,220			9,606
Trade name portfolio not subject to amortization	indefinite	32,076			32,076
In-process research and development	3 years	6,272			5,602
Other	7 years	1,638			1,929
Acquired identifiable intangibles		238,029			246,069
Less accumulated amortization		(93,154		)	(80,841		)
Net acquired identifiable intangibles		144,875			165,228
Patents	7 years	6,086			6,112
Less accumulated amortization		(4,253		)	(3,399		)
Net patents		1,833			2,713
Acquired in-place leases and other	10 years	446			456
Less accumulated amortization		(309		)	(267		)
Net acquired in-place leases and other		137			189
		$	146,845		$	168,130

Estimated future aggregate amortization expense

For intangible assets recorded at December 31, 2018, the estimated future aggregate amortization expense for the years ending December 31, 2019 through 2023 is approximately (in thousands):

2019	$	23,918
2020	22,049
2021	19,588
2022	18,726
2023	15,426