Restructuring - Restructuring charges (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended			4 Months Ended	5 Months Ended	7 Months Ended	8 Months Ended	12 Months Ended
	Jul. 31, 2021	Jan. 31, 2022	Oct. 31, 2021	Apr. 30, 2020	Jun. 11, 2021	Jan. 31, 2021	Aug. 27, 2020	Jan. 31, 2022	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Restructuring
Restructuring	$ 316	$ 2,603	$ 777		$ (703)	$ 4,341	$ 1,179	$ 3,696			$ 1,900
Restructuring credit					$ 700
Financial Designation, Predecessor and Successor [Fixed List]				Predecessor	Predecessor	Predecessor	Predecessor	Successor	Successor	Predecessor	Predecessor