Goodwill, Long-lived Assets and Other Intangibles Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Goodwill [Line Items]
Goodwill impairment loss	$ 0	$ 0	$ 0	$ 0
Goodwill [Roll Forward]
Goodwill Beginning balance			50,942
Goodwill, Measurement Period Adjustment			(33)
Goodwill, Foreign Currency Translation Gain (Loss)			(82)
Goodwill Ending balance	50,827		50,827
Applied Technology [Member]
Goodwill [Roll Forward]
Goodwill Beginning balance			17,076
Goodwill, Measurement Period Adjustment			(33)
Goodwill, Foreign Currency Translation Gain (Loss)			(82)
Goodwill Ending balance	16,961		16,961
Engineered Films [Member]
Goodwill [Roll Forward]
Goodwill Beginning balance			33,232
Goodwill, Measurement Period Adjustment			0
Goodwill, Foreign Currency Translation Gain (Loss)			0
Goodwill Ending balance	33,232		33,232
Aerostar [Member]
Goodwill [Roll Forward]
Goodwill Beginning balance			634
Goodwill, Measurement Period Adjustment			0
Goodwill, Foreign Currency Translation Gain (Loss)			0
Goodwill Ending balance	$ 634		$ 634