BUSINESS SEGMENT INFORMATION (Details) (USD $)	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 segment	Sep. 30, 2013	Sep. 30, 2012
BUSINESS SEGMENT INFORMATION
Number of primary business segments									3
Revenue recognition
Sales	$ 396,366,000	$ 340,357,000	$ 354,492,000	$ 307,137,000	$ 340,776,000	$ 337,226,000	$ 368,609,000	$ 314,796,000	$ 1,398,352,000	$ 1,361,407,000	$ 1,404,084,000
Operating income (loss)	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
Depreciation and amortization									30,440,000	25,359,000	22,857,000
Assets	1,194,606,000				1,109,618,000				1,194,606,000	1,109,618,000	1,014,600,000
Capital expenditures									16,620,000	9,052,000	14,226,000
Transportation Systems
Revenue recognition
Sales									599,700,000	529,500,000	522,200,000
Operating income (loss)									65,900,000	66,800,000	84,600,000
Depreciation and amortization									11,500,000	5,000,000	3,700,000
Assets	422,200,000				369,800,000				422,200,000	369,800,000	268,400,000
Capital expenditures									1,800,000	2,800,000	2,700,000
Sales to Transport for London									213,200,000	193,400,000	184,700,000
Mission Support Services
Revenue recognition
Sales									398,100,000	468,700,000	491,400,000
Operating income (loss)									7,800,000	(36,100,000)	21,100,000
Depreciation and amortization									10,700,000	13,000,000	12,500,000
Assets	195,800,000				205,200,000				195,800,000	205,200,000	212,800,000
Capital expenditures										300,000	1,100,000
Defense Systems
Revenue recognition
Sales									400,600,000	363,000,000	389,400,000
Operating income (loss)									26,800,000	14,200,000	35,300,000
Depreciation and amortization									7,400,000	6,100,000	5,500,000
Assets	252,400,000				228,900,000				252,400,000	228,900,000	211,200,000
Capital expenditures									13,200,000	4,600,000	8,900,000
Other
Revenue recognition
Sales										200,000	1,100,000
Corporate and other
Revenue recognition
Depreciation and amortization									800,000	1,300,000	1,200,000
Assets	324,200,000				304,500,000				324,200,000	304,500,000	322,200,000
Capital expenditures									1,600,000	1,400,000	1,500,000
MSS and CDS Segments
Revenue recognition
Sales to U.S. government agencies									651,500,000	691,800,000	699,400,000
Unallocated corporate expenses and other
Revenue recognition
Operating income (loss)									$ (8,000,000)	$ (4,200,000)	$ (4,800,000)