Operating Segments and Related Information (Details 3) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	$ 691,383	$ 675,263
Surveillance
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	284,147	309,473
Instruments
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	121,995	119,629
OEM & Emerging Markets
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	91,582	79,053
Maritime
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	72,802	67,775
Security
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	90,271	59,182
Detection
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	$ 30,586	$ 40,151