Operating Segments and Related Information Operating Segments and Related Information (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	$ 609,059	$ 631,292
Surveillance
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	271,834	282,839
Instruments
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	109,957	117,336
OEM & Emerging Markets
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	85,112	88,317
Maritime
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	79,462	68,915
Security
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	36,916	45,053
Detection
Segment Reporting, Asset Reconciling Item [Line Items]
Segment assets (accounts receivable, net and inventories)	$ 25,778	$ 28,832