Cover - USD ($)	12 Months Ended
	Dec. 31, 2022	Feb. 28, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36485
Entity Registrant Name	ARDELYX, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1303944
Entity Address, Address Line One	400 FIFTH AVE.
Entity Address, Address Line Two	SUITE 210
Entity Address, City or Town	WALTHAM
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02451
City Area Code	510
Local Phone Number	745-1700
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	ARDX
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 89,227,062
Entity Common Stock, Shares Outstanding		206,492,664
Entity Central Index Key	0001437402
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference	Portions of the Registrant’s Definitive Proxy Statement for its 2023 Annual Meeting of Stockholders, which will be filed with the Commission within 120 days of December 31, 2022, the close of the Registrant’s 2022 fiscal year, are incorporated by reference into Part III of this Report.