Realized and Unrealized Gains and Loss (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 28, 2025	Sep. 29, 2024	Sep. 28, 2025	Sep. 29, 2024
Realized gains and losses included in 'Other (income) expense, net' in the condensed consolidated statement of operations
Realized gains	$ 0.7	$ 0.8	$ 1.8	$ 2.1
Realized losses	0.0	0.0	1.3	0.3
Unrealized gains and losses on equity securities included in 'Other (income) expense, net' in the condensed consolidated statement of operations
Unrealized gains on equity securities	3.1	2.2	7.4	5.4
Unrealized losses on equity securities	$ 0.1	$ 0.0	$ 3.2	$ 0.0

$ 0.7

$ 0.8

$ 1.8

$ 2.1

$ 0.1

$ 0.0

$ 3.2

$ 0.0