Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2023	Feb. 06, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-15149
Entity Registrant Name	LENNOX INTERNATIONAL INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	42-0991521
Entity Address, Address Line One	2140 Lake Park Blvd
Entity Address, City or Town	Richardson
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75080
City Area Code	972
Local Phone Number	497-5000
Title of 12(b) Security	Common stock, $0.01 par value per share
Trading Symbol	LII
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
Entity Shell Company	false
Entity Public Float			$ 11.6
Entity Common Stock, Shares Outstanding		35,586,684
Documents Incorporated by Reference	Portions of the registrant’s 2024 Definitive Proxy Statement to be filed with the Securities and Exchange Commission in connection with the registrant’s 2024 Annual Meeting of Stockholders to be held on May 16, 2024 are incorporated by reference into Part III of this report.
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Central Index Key	0001069202
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY