Financial and Product Information About Foreign and Domestic Operations Geographical Data (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	Aug. 31, 2017	May 31, 2017	Feb. 28, 2017	Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 107,457	$ 129,637	$ 108,867	$ 100,855	$ 122,236	$ 156,563	$ 113,470	$ 114,823	$ 514,530	$ 446,816	$ 507,092	$ 514,530
Long-Lived Assets	60,493				65,259				65,589	60,493	65,259	65,589
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									59,856	49,970	57,447
Long-Lived Assets	11,553				12,979				11,688	11,553	12,979	11,688
Non-US [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									4,809	3,012	3,383
Long-Lived Assets	70				3,709				3,964	70	3,709	3,964
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax									449,865	393,834	446,262
Long-Lived Assets	$ 48,870				$ 48,571				$ 49,937	$ 48,870	$ 48,571	$ 49,937