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PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jan. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Property and equipment
Property and equipment, gross			$ 246,836	$ 389,655
Less accumulated depreciation and amortization			(131,312)	(248,116)
Property and equipment, net			115,524	141,539
Depreciation expense			43,300	56,000	$ 52,200
AS&E facility in Billerica, MA
Property and equipment
Purchase of property and equipment		$ 19,800
Mexican government
Contract with Mexican government
Term of agreement with Mexican government to provide security screening services	2 years
Net book value of certain fixed assets transferred	$ 29,500
Recognized amortization expense			6,900
Mexican government \| Prepaid expenses and other current assets
Contract with Mexican government
Remaining cost to obtain the contract			14,700
Mexican government \| Other assets
Contract with Mexican government
Remaining cost to obtain the contract			7,900
Land
Property and equipment
Property and equipment, gross			16,569	14,212
Buildings, civil works and improvements
Property and equipment
Property and equipment, gross			$ 56,585	157,123
Buildings, civil works and improvements \| Minimum
Property and equipment
Estimated Useful Lives			5 years
Buildings, civil works and improvements \| Maximum
Property and equipment
Estimated Useful Lives			40 years
Leasehold improvements
Property and equipment
Property and equipment, gross			$ 9,681	9,025
Leasehold improvements \| Minimum
Property and equipment
Estimated Useful Lives			1 year
Leasehold improvements \| Maximum
Property and equipment
Estimated Useful Lives			13 years
Equipment and tooling
Property and equipment
Property and equipment, gross			$ 117,294	166,991
Equipment and tooling \| Minimum
Property and equipment
Estimated Useful Lives			3 years
Equipment and tooling \| Maximum
Property and equipment
Estimated Useful Lives			10 years
Furniture and fixtures
Property and equipment
Property and equipment, gross			$ 3,331	3,371
Furniture and fixtures \| Minimum
Property and equipment
Estimated Useful Lives			3 years
Furniture and fixtures \| Maximum
Property and equipment
Estimated Useful Lives			10 years
Computer equipment
Property and equipment
Property and equipment, gross			$ 18,759	17,991
Computer equipment \| Minimum
Property and equipment
Estimated Useful Lives			3 years
Computer equipment \| Maximum
Property and equipment
Estimated Useful Lives			5 years
Computer software
Property and equipment
Property and equipment, gross			$ 19,509	17,303
Computer software \| Minimum
Property and equipment
Estimated Useful Lives			3 years
Computer software \| Maximum
Property and equipment
Estimated Useful Lives			10 years
Computer software implementation in process
Property and equipment
Property and equipment, gross			$ 4,318	2,590
Construction in process
Property and equipment
Property and equipment, gross			$ 790	$ 1,049