Pension - Schedule of Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Net loss (gain)	$ (11.5)	$ 19.5	$ 2.6
Pension Benefits
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Net loss (gain)	(11.5)	19.5	2.4
Amortization of net loss	(1.9)	(1.6)	(1.5)
Amortization of prior service cost	0.0	0.0	0.1
Settlements	(66.3)	0.0	0.0
Curtailments	0.0	0.0	(0.3)
Total recognized in other comprehensive income (loss)	(79.7)	17.9	0.7
Total Recognized in Net Periodic Benefit Cost and Other Comprehensive Income (Loss)	$ (9.7)	$ 18.5	$ 2.9