Document And Entity Information - shares	3 Months Ended
	Sep. 30, 2020	Oct. 26, 2020
Document And Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 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 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		144,915,153
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--06-30
Entity Central Index Key	0000943819