Operating Segments and Related Information (Details 4) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	$ 601,247	$ 596,316
Surveillance
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	120,549	120,145
Instruments
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	151,974	149,582
OEM & Emerging Markets
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	71,081	69,973
Maritime
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	105,413	106,549
Detection
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	$ 48,081	$ 48,112