Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net revenues	$ 893.9	$ 923.0
Cost of goods sold	502.5	532.0
Selling and administrative expenses	219.3	220.0
Operating income	172.1	171.0
Interest expense	22.9	23.6
Other income, net	(3.7)	(0.3)
Earnings before income taxes	152.9	147.7
Provision for income taxes	29.1	24.1
Net earnings	123.8	123.6
Less: Net earnings attributable to noncontrolling interests	0.0	0.1
Net earnings attributable to Allegion plc	$ 123.8	$ 123.5
Earnings per share attributable to Allegion plc ordinary shareholders:
Basic net earnings (in dollars per share)	$ 1.41	$ 1.40
Diluted net earnings (in dollars per share)	$ 1.41	$ 1.40
Weighted-average shares outstanding:
Basic (in shares)	87.6	88.0
Diluted (in shares)	88.1	88.4
Total comprehensive income	$ 99.8	$ 133.9
Less: Total comprehensive income attributable to noncontrolling interests	0.0	0.2
Total comprehensive income attributable to Allegion plc	$ 99.8	$ 133.7