Debt - Sale of accounts receivable (Details) - U.K. Subsidiary $ in Thousands	12 Months Ended
Mar. 31, 2020 USD ($)
Debt
Receivables sold under the terms of the financing agreement	$ 30,702
Amounts due related to a financing agreement to sell certain accounts receivable balances	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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