Operating Segments and Related Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 434,366	$ 375,366	$ 369,380	$ 351,542	$ 400,319	$ 358,141	$ 389,329	$ 348,583	$ 1,530,654	$ 1,496,372	$ 1,405,358
Intersegment revenue									0	0	0
Earnings (loss) from operations									259,244	240,743	303,330
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									492,213	531,338	560,165
Intersegment revenue									7,209	5,928	16,418
Earnings (loss) from operations									113,048	122,095	170,015
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									354,124	337,531	339,029
Intersegment revenue									1,793	7,312	11,738
Earnings (loss) from operations									98,954	81,070	87,133
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									226,865	207,204	194,982
Intersegment revenue									21,856	25,063	31,448
Earnings (loss) from operations									64,423	52,724	61,995
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									192,636	189,076	178,294
Intersegment revenue									2,936	0	7
Earnings (loss) from operations									24,494	22,287	18,467
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									179,090	141,005	52,013
Intersegment revenue									11,017	0	0
Earnings (loss) from operations									24,871	17,340	15,133
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									85,726	90,218	80,875
Intersegment revenue									95	1,730	4,233
Earnings (loss) from operations									10,958	8,888	588
Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue									44,906	40,033	63,844
Other Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Earnings (loss) from operations									$ (77,504)	$ (63,661)	$ (50,001)