Intangible Assets (Details) - USD ($) $ in Thousands		12 Months Ended
	Nov. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets [Line Items]
In Process Research and Development		$ 6,272	$ 5,602
Net carrying amount		146,845	168,130
Aggregate amortization expense		24,700	27,500	$ 18,400
2017		23,918
2018		22,049
2019		19,588
2020		18,726
2021		15,426
Armasight, Inc. and Point Grey Research, Inc.
Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		47,400
Prox Dynamics, AS [Member]
Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 123,100		31,400
acquired indefinite life intangible asset	31400000
Fishidy [Member]
Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		3,782
Acquired identifiable intangibles
Intangible Assets [Line Items]
Acquired identifiable intangibles,Gross		238,029	246,069
Less accumulated amortization		(93,154)	(80,841)
Net carrying amount		144,875	165,228
Aggregate amortization expense		(24,524)	(27,391)	$ (18,266)
Product technology | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 117,563	123,474
Weighted average estimated useful life		10 years
Trade name | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 73,260	73,382
Weighted average estimated useful life		11 years
Trademarks and tradename portfolios | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 7,220	9,606
Weighted average estimated useful life		12 years
Tradename not subject to amortization | Acquired identifiable intangibles
Intangible Assets [Line Items]
acquired indefinite life intangible asset		indefinite
In Process Research and Development | Acquired identifiable intangibles
Intangible Assets [Line Items]
Weighted average estimated useful life		3 years
Trade Secrets | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 1,638	1,929
Weighted average estimated useful life		7 years
Patents | Nonacquired intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 6,086	6,112
Less accumulated amortization		(4,253)	(3,399)
Net carrying amount		$ 1,833	2,713
Weighted average estimated useful life		7 years
Acquired in-place leases and other | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 446	456
Less accumulated amortization		(309)	(267)
Net carrying amount		$ 137	189
Acquired in-place leases and other | Nonacquired intangibles
Intangible Assets [Line Items]
Weighted average estimated useful life		10 years
Trade Names [Member] | Prox Dynamics, AS [Member]
Intangible Assets [Line Items]
acquired indefinite life intangible asset	1400
Weighted average estimated useful life	8 years
Trade Names [Member] | Acquired identifiable intangibles
Intangible Assets [Line Items]
Infinite-Lived Intangibles, Gross		$ 32,076	$ 32,076