Operating Segments and Related Information (Details 4) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	$ 592,946	$ 596,316
Surveillance
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	120,113	120,145
Instruments
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	150,457	149,582
OEM & Emerging Markets
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	70,332	69,973
Maritime
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	102,025	106,549
Detection
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting Information Goodwill	$ 48,015	$ 48,112