Document And Entity Information - USD ($)	12 Months Ended
	Jun. 30, 2020	Aug. 07, 2020	Dec. 31, 2019
Document And Entity Information [Abstract]
Document Type	10-K/A
Document Annual Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	001-15317
Entity Registrant Name	ResMed Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	98-0152841
Entity Address, Address Line One	9001 Spectrum Center Blvd.
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92123
Entity Address, Country	US
City Area Code	858
Local Phone Number	836-5000
Title of 12(b) Security	Common Stock, par value $0.004 per share
Trading Symbol	RMD
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Current Fiscal Year End Date	--06-30
Entity Public Float			$ 22,240,443,784
Entity Common Stock, Shares Outstanding		144,900,654
Amendment Description	This Amendment No. 1 on Form 10-K/A (this “Amendment”) amends the Annual Report on Form 10-K of ResMed Inc. for the fiscal year ended June 30, 2020, as filed with the Securities and Exchange Commission on August 12, 2020 (the “Original Filing”). The Consent of Independent Registered Public Accounting Firm (the “Auditor Consent”) was inadvertently omitted in the Original Filing. This Amendment is being filed solely to file the Auditor Consent. No other changes were made to the Original Filing. Further, no attempt has been made in this Amendment to modify or update the other disclosures presented in the Original Filing. This Amendment does not reflect events occurring after the filing of the Form 10-K (i.e., occurring after August 12, 2020) or modify or update those disclosures that may be affected by subsequent events. Accordingly, this Amendment should be read in conjunction with the Form 10-K and the registrant’s other filings with the Securities and Exchange Commission. In addition, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), new certifications by the Company’s principal executive officer and principal financial officer are filed herewith as exhibits to this Amendment No. 1 pursuant to Rule 13a-14(a) or 15d-14(a) of the Exchange Act. As no financial statements have been included in this Amendment No. 1 and it does not contain or amend any disclosure with respect to Items 307 or 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted. The Company is not including certifications pursuant to Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350) as no financial statements are being filed with this Amendment.
Amendment Flag	true
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000943819