Goodwill and Other Intangibles Inventory write-downs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Cost of Sales [Member] | Aerostar [Member]
Schedule of Inventory write-down [Line Items]
Inventory Write-down	$ 2,278	$ 0	$ 2,278	$ 0