Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 24, 2015
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Trading Symbol	RGLS
Entity Registrant Name	REGULUS THERAPEUTICS INC.
Entity Central Index Key	0001505512
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		51,919,532