Condensed Consolidated Statements of Convertible Preferred Stock & Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands		3 Months Ended
Apr. 01, 2024	Jun. 30, 2024
Common stock reserved for the conversion of Series A convertible preferred stock
Issuance costs	$ 2,250	$ 2,250

Amount of issuance cost incurred on issuance of temporary equity.

No definition available.

Name:	rytm_TemporaryEquityStockIssuanceCost
Namespace Prefix:	rytm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration