Segments - Revenue and Long-Lived Assets, Geographic Region (Detail) - USD ($) $ in Millions	Mar. 29, 2025	Dec. 28, 2024
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	$ 8,069.0	$ 7,896.8
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	6,441.7	6,355.7
Operating Segments | Commercial & Industrial Group
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	1,268.1	1,230.8
Operating Segments | Snap-on Tools Group
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	949.9	937.5
Operating Segments | Repair Systems & Information Group
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	1,737.4	1,695.5
Operating Segments | Financial Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	2,486.3	2,491.9
Corporate
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	1,716.6	1,633.0
Intersegment net sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	$ (89.3)	$ (91.9)