CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Income Statement [Abstract]
Net loss	$ (100,357)	$ (14,816)
Other comprehensive gain in relation to defined benefit plans, net of tax	268	397
Changes in unrealized gain (loss) on marketable securities, net of tax	(30)	1,639
Foreign currency translation adjustments, net of tax	(384)	0
Comprehensive loss	$ (100,503)	$ (12,780)