Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net revenues	$ 912.5	$ 773.1	$ 1,835.5	$ 1,496.7
Cost of goods sold	510.6	458.1	1,042.6	893.0
Selling and administrative expenses	217.3	167.9	437.3	339.6
Operating income	184.6	147.1	355.6	264.1
Interest expense	23.7	17.2	47.3	29.1
Other income, net	(1.6)	(3.4)	(1.9)	(5.6)
Earnings before income taxes	162.5	133.3	310.2	240.6
Provision for income taxes	20.5	18.1	44.6	32.3
Net earnings	142.0	115.2	265.6	208.3
Less: Net earnings attributable to noncontrolling interests	0.0	0.1	0.1	0.2
Net earnings attributable to Allegion plc	$ 142.0	$ 115.1	$ 265.5	$ 208.1
Earnings per share attributable to Allegion plc ordinary shareholders:
Basic net earnings (in dollars per share)	$ 1.62	$ 1.31	$ 3.02	$ 2.36
Diluted net earnings (in dollars per share)	$ 1.61	$ 1.30	$ 3.01	$ 2.35
Weighted-average shares outstanding:
Basic (in shares)	87.9	87.9	88.0	88.0
Diluted (in shares)	88.3	88.2	88.3	88.4
Total comprehensive income	$ 149.9	$ 65.4	$ 283.8	$ 137.5
Less: Total comprehensive loss attributable to noncontrolling interests	(0.9)	(0.5)	(0.7)	(0.4)
Total comprehensive income attributable to Allegion plc	$ 150.8	$ 65.9	$ 284.5	$ 137.9