Cover Page - shares	6 Months Ended
	Jun. 30, 2022	Jul. 29, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-39186
Entity Registrant Name	ARCUTIS BIOTHERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-2974255
Entity Address, Address Line One	3027 Townsgate Road
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Westlake Village
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91361
City Area Code	805
Local Phone Number	418-5006
Title of 12(b) Security	Common Stock, par value $0.0001
Trading Symbol	ARQT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		51,562,525
Entity Central Index Key	0001787306
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Amendment Flag	false