Net loss per common stock - Additional Information (Detail)	3 Months Ended
Mar. 31, 2020 shares
Pre Funded Common Stock Warrants [Member]
Number of pre-funded warrants included in computation of basic and diluted net loss per common stock	10,925,481

Fully vested and exercisable prefunded warrants included in the computation of basic and diluted net loss per common stock.

No definition available.

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