Share Plans - Stock Option Activity (Detail) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) $ / shares shares
Shares
Beginning balance (shares) | shares	1.7
Granted (shares) | shares	0.1
Exercised (shares) | shares	(0.5)
Ending balance (shares) | shares	1.3
Options exercisable | shares	0.9
Options expected to vest at end of period | shares	0.4
Weighted Average Exercise Price
Beginning balance (USD per share) | $ / shares	$ 50.35
Granted (USD per share) | $ / shares	100.37
Exercised (USD per share) | $ / shares	43.73
Ending Balance (USD per share) | $ / shares	57.48
Options exercisable at end of period (USD per share) | $ / shares	51.43
Options expected to vest at end of period (USD per share) | $ / shares	$ 73.37
Weighted Average Remaining Contractual Life
Ending balance	5 years 7 months 6 days
Options exercisable at end of period	4 years 8 months 12 days
Options expected to vest at end of period	7 years 9 months 18 days
Aggregate Intrinsic value
Balance at end of period | $	$ 60.0
Options exercisable at end of period | $	49.3
Options expected to vest at end of period | $	$ 10.7