Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATIONThe accompanying Condensed and Consolidated Financial Statements of Allegion plc, an Irish public limited company, and its consolidated subsidiaries ("Allegion" or "the Company"), reflect the consolidated operations of the Company and have been prepared in accordance with United States ("U.S.") Securities and Exchange Commission ("SEC") interim reporting requirements. Accordingly, the accompanying Condensed and Consolidated Financial Statements do not include all disclosures required by accounting principles generally accepted in the United States of America ("GAAP") for full financial statements and should be read in conjunction with the Consolidated Financial Statements included in the Allegion Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of management, the accompanying Condensed and Consolidated Financial Statements contain all adjustments, which include normal recurring adjustments, necessary to state fairly the consolidated unaudited results for the interim periods presented.