SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Convertible preferred shares (Details)	May 03, 2022 shares
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Number of total convertible preferred shares issued and outstanding converted to ordinary shares	7,820,914

Number of shares converted from temporary equity to permanent equity.

No definition available.

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Namespace Prefix:	blte_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration