CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK (Parenthetical) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($)
Series B Convertible Preferred Stock
Issuance costs	$ 50
Series C Convertible Preferred Stock
Issuance costs	$ 314

The cost incurred in connection with issuance of temporary equity.

No definition available.

Name:	xlo_TemporaryEquityIssuanceCosts
Namespace Prefix:	xlo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration