Operating Segments and Related Information (Details 4) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	$ 541,971	$ 553,335
Surveillance
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	120,358	121,268
Instruments
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	150,803	155,527
OEM & Emerging Markets
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	70,470	72,687
Maritime
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	107,883	109,980
Security
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	44,322	45,710
Detection
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	$ 48,135	$ 48,163