v3.25.2
Business Segment Information (Summary of Operations by Reportable Segments) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Segment Reporting Information [Line Items]        
Net revenues $ 1,022.0 $ 965.6 $ 1,963.9 $ 1,859.5
Cost of goods sold 555.5 537.3 1,074.9 1,039.8
Selling and administrative expenses 246.8 219.3 472.9 438.6
Operating income (loss) 219.7 209.0 416.1 381.1
Interest expense 24.6 25.1 49.3 48.0
Other income, net (5.3) (5.1) (8.8) (8.8)
Total earnings before income taxes 200.4 189.0 375.6 341.9
Operating Segments        
Segment Reporting Information [Line Items]        
Operating income (loss) 252.3 232.0 475.4 432.0
Operating Segments | Allegion Americas        
Segment Reporting Information [Line Items]        
Net revenues 821.5 770.7 1,579.3 1,480.0
Cost of goods sold 440.7 425.2 853.2 818.4
Selling and administrative expenses 144.2 131.2 278.1 260.3
Operating income (loss) 236.6 214.3 448.0 401.3
Operating Segments | Allegion International        
Segment Reporting Information [Line Items]        
Net revenues 200.5 194.9 384.6 379.5
Cost of goods sold 114.8 113.2 221.7 223.5
Selling and administrative expenses 70.0 64.0 135.5 125.3
Operating income (loss) 15.7 17.7 27.4 30.7
Corporate, Non-Segment        
Segment Reporting Information [Line Items]        
Operating income (loss) $ 32.6 $ 23.0 $ 59.3 $ 50.9