Cover Page - shares	6 Months Ended
	Jun. 30, 2019	Jul. 22, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	001-35971
Entity Central Index Key	0001579241
Entity Registrant Name	Allegion plc
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	98-1108930
Entity Address, Address Line One	Block D
Entity Address, Address Line Two	Iveagh Court
Entity Address, Address Line Three	Harcourt Road
Entity Address, City or Town	Dublin
Entity Address, Postal Zip Code	2
Entity Address, Country	IE
Country Region	353
City Area Code	1
Local Phone Number	2546200
Title of 12(b) Security	Ordinary shares, par value $0.01 per share
Trading Symbol	ALLE
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		93,376,344