v3.26.1
Business Segment Information (Summary of Operations by Reportable Segments) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Net revenues $ 1,151.5 $ 1,022.0 $ 2,185.1 $ 1,963.9
Cost of goods sold 634.0 555.5 1,213.1 1,074.9
Selling and administrative expenses 262.8 246.8 522.0 472.9
Operating income (loss) 254.7 219.7 450.0 416.1
Interest expense 24.8 24.6 49.0 49.3
Other expense (income), net 2.0 (5.3) 1.6 (8.8)
Total earnings before income taxes 227.9 200.4 399.4 375.6
Operating Segments        
Segment Reporting [Line Items]        
Operating income (loss) 281.6 252.3 505.0 475.4
Operating Segments | Allegion Americas        
Segment Reporting [Line Items]        
Net revenues 918.6 821.5 1,728.5 1,579.3
Cost of goods sold 498.4 440.7 946.7 853.2
Selling and administrative expenses 153.4 144.2 299.9 278.1
Operating income (loss) 266.8 236.6 481.9 448.0
Operating Segments | Allegion International        
Segment Reporting [Line Items]        
Net revenues 232.9 200.5 456.6 384.6
Cost of goods sold 135.6 114.8 266.4 221.7
Selling and administrative expenses 82.5 70.0 167.1 135.5
Operating income (loss) 14.8 15.7 23.1 27.4
Depreciation, Depletion and Amortization 14.4 10.8 28.8 21.2
Operating Segments | alle_Allegion Americas        
Segment Reporting [Line Items]        
Depreciation, Depletion and Amortization 20.5 19.9 40.8 38.8
Corporate, Non-Segment        
Segment Reporting [Line Items]        
Operating income (loss) $ 26.9 $ 32.6 $ 55.0 $ 59.3