Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Intangible Assets [Line Items]
In Process Research and Development	$ 4,700	$ 2,250
Net carrying amount	168,460	141,302
Aggregate amortization expense	18,400	16,400	$ 21,100
2017	23,594
2018	19,962
2019	19,041
2020	16,095
2021	14,411
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
DVTEL [Member]
Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	27,380	27,380
Acquired identifiable intangibles
Intangible Assets [Line Items]
Acquired identifiable intangibles,Gross	238,089	194,391
Less accumulated amortization	(73,535)	(58,173)
Net carrying amount	164,554	136,218
Product technology | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 98,895	76,182
Weighted average estimated useful life	11 years
Trade name | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 87,013	69,272
Weighted average estimated useful life	11 years
Trademarks and tradename portfolios | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 8,160	7,540
Weighted average estimated useful life	14 years
Tradename not subject to amortization | Acquired identifiable intangibles
Intangible Assets [Line Items]
acquired indefinite life intangible asset	indefinite
Trade Secrets | Acquired identifiable intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 1,827	1,474
Weighted average estimated useful life	3 years
Patents | Nonacquired intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 6,083	6,104
Less accumulated amortization	(2,531)	(1,671)
Net carrying amount	$ 3,552	4,433
Weighted average estimated useful life	7 years
Acquired in-place leases and other | Nonacquired intangibles
Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 2,074	2,080
Less accumulated amortization	(1,720)	(1,429)
Net carrying amount	$ 354	651
Weighted average estimated useful life	7 years
Trade Names [Member] | Acquired identifiable intangibles
Intangible Assets [Line Items]
Infinite-Lived Intangibles, Gross	$ 37,494	$ 37,673