BUSINESS SEGMENT INFORMATION (Details 3) (USD $)	3 Months Ended								12 Months Ended			1 Months Ended	12 Months Ended						3 Months Ended		12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014 item	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2014 Transportation Systems item	Sep. 30, 2014 Transportation Systems	Sep. 30, 2013 Transportation Systems	Sep. 30, 2012 Transportation Systems	Sep. 30, 2014 Defense Systems	Sep. 30, 2013 Defense Systems item	Sep. 30, 2012 Defense Systems	Sep. 30, 2014 Change in estimated total costs Adjustment	Sep. 30, 2013 Change in estimated total costs Adjustment	Sep. 30, 2014 Change in estimated total costs Adjustment	Sep. 30, 2013 Change in estimated total costs Adjustment	Sep. 30, 2012 Change in estimated total costs Adjustment
Revenue recognition
Increase (decrease) in operating income	$ 39,268,000	$ 19,215,000	$ 22,177,000	$ 11,830,000	$ (44,055,000)	$ 26,905,000	$ 37,376,000	$ 20,509,000	$ 92,490,000	$ 40,735,000	$ 136,205,000		$ 65,900,000	$ 66,800,000	$ 84,600,000	$ 26,800,000	$ 14,200,000	$ 35,300,000	$ (10,700,000)	$ 9,900,000	$ 1,300,000	$ 1,700,000	$ 15,700,000
Increase (decrease) in net income									69,580,000	25,269,000	97,631,000								(7,600,000)	6,600,000	(3,500,000)	300,000	10,700,000
Increase (decrease) in net income per common share (in dollars per share)	$ 1.22	$ 0.46	$ 0.60	$ 0.31	$ (1.39)	$ 0.69	$ 1.11	$ 0.53	$ 2.59	$ 0.94	$ 3.64								$ (0.28)	$ 0.25	$ 0.13	$ 0.01	$ 0.40
Number of transportation systems service contracts contains annual system usage incentives									1
Sales related to annual system usage incentives									12,200,000	13,200,000	12,200,000
Reduction in employee headcount												20					230
Restructuring costs									$ 1,094,000	$ 8,139,000		$ 1,100,000