Shareholders' Equity | Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) balance	$ 1,464	$ 43,786
Other comprehensive income (loss), before reclassification	(56,145)	(41,098)
Reclassification of (gain) loss form AOCI into income	(417)	364
Accumulated other comprehensive income (loss) balance	(55,098)	3,052
Foreign currency translation adjustment, net of taxes
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) balance	1,449	43,786
Other comprehensive income (loss), before reclassification	(56,547)	(40,523)
Reclassification of (gain) loss form AOCI into income	0	0
Accumulated other comprehensive income (loss) balance	(55,098)	3,263
Unrealized gains (losses) on cash flow hedges, net of taxes
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) balance	15	0
Other comprehensive income (loss), before reclassification	402	(575)
Reclassification of (gain) loss form AOCI into income	(417)	364
Accumulated other comprehensive income (loss) balance	$ 0	$ (211)