Operating Segments and Related Information (Details 4) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	$ 758,547	$ 723,391
Segment Reporting Information goodwill	930,846	801,406
Surveillance
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	290,353	283,324
Segment Reporting Information goodwill	259,400	152,383
Instruments
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	132,642	114,681
Segment Reporting Information goodwill	153,677	147,595
Security
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	95,063	93,174
Segment Reporting Information goodwill	111,883	102,983
OEM & Emerging Markets [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	141,212	144,862
Segment Reporting Information goodwill	255,490	252,647
Maritime [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	65,276	61,494
Segment Reporting Information goodwill	102,384	97,860
Detection
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	34,001	25,856
Segment Reporting Information goodwill	$ 48,012	$ 47,938