| Restructuring - Restructuring charges (Details) - USD ($) $ in Thousands | 1 Months Ended | 2 Months Ended | 3 Months Ended | 4 Months Ended | 5 Months Ended | 7 Months Ended | 9 Months Ended | 12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Jun. 12, 2021 | Aug. 28, 2020 | Jun. 11, 2021 | Aug. 27, 2020 | Jul. 31, 2021 | Jul. 31, 2021 | Oct. 31, 2020 | Oct. 31, 2021 | Apr. 30, 2021 | Oct. 31, 2020 | Jul. 31, 2020 | Apr. 30, 2020 | Jun. 11, 2021 | Oct. 31, 2021 | Aug. 27, 2020 | Oct. 31, 2020 | Jan. 31, 2021 | Jan. 31, 2020 | |
| Restructuring | ||||||||||||||||||
| Restructuring charges incurred | $ 38 | $ 80 | $ 777 | $ (703) | $ 1,093 | $ 1,179 | ||||||||||||
| Restructuring credit | $ (700) | |||||||||||||||||
| Financial Designation, Predecessor and Successor [Fixed List] | Successor | Predecessor | Predecessor | Predecessor | Successor | Successor | Predecessor | Successor | Predecessor | Predecessor | Predecessor | Predecessor | Predecessor | Successor | Predecessor | Predecessor | Predecessor | Predecessor | 
| X | ||||||||||
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- Definition Amount of expense (reversal of expense) which increases (decreases) the restructuring reserve from an acquisition adjustment. No definition available. 
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| X | ||||||||||
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- Definition Indicates designation of financial information when substantially all business or separately identifiable line of business transfers from one entity to another entity. Acceptable values are "Predecessor" and "Successor". Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- References No definition available. 
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| X | ||||||||||
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- Definition Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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