Goodwil, Long-lived Assets, and Other Charges Long-lived Asset Impairment details (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Oct. 31, 2016	Jan. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Impaired Long-Lived Assets Held and Used [Line Items]
Finite-Lived Intangible Assets, Net		$ 12,956				$ 12,048	$ 12,956	$ 18,490
Impairment of Long-Lived Assets Held-for-use						87	3,826	0
Vista Reporting Unit [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived assets, fair value			$ 103		$ 103
Impairment of Long-Lived Assets Held-for-use			3,813		3,813		3,826	0
Long-Lived Assets			3,916		3,916
Lighter than Air asset group [Member] | Aerostar [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived assets excess of fair value over carrying value	$ 110,000			$ 110,000
Long-lived asset, percentage fair value exceeds carrying value	800.00%			800.00%
Radar Technology and Radar Customers [Member] | Aerostar [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived assets, fair value	$ 175			$ 175
Finite-Lived Intangible Assets, Net	262			262
Radar Technology and Radar Customers [Member] | Aerostar [Member] | Operating Income (Loss) [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use	87			87		87
Radar Technology and Radar Customers [Member] | Vista Reporting Unit [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use	0		3,154		3,154	0	3,154
Patented Technology [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Finite-Lived Intangible Assets, Net		2,090				2,158	2,090	$ 2,002
Patented Technology [Member] | Aerostar [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use	25			25		25
Patented Technology [Member] | Vista Reporting Unit [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use		$ 13	105		105		118
Property, Plant and Equipment [Member] | Aerostar [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 62			$ 62		$ 62
Property, Plant and Equipment [Member] | Vista Reporting Unit [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use			$ 554		$ 554		$ 554