Credit risk related to accounts receivables - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2021	Mar. 31, 2021
Receivables [Abstract]
Net accounts receivables pledged as security	$ 3.2	$ 2.3

The carrying amount, as of the date of the latest financial statement presented, of finance receivables which are owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

Name:	us-gaap_PledgedAssetsNotSeparatelyReportedFinanceReceivables
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant