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Share-Based Compensation Plans (Narrative) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost related to unvested RSUs and PRSUs	$ 33.2
Incentive Compensation Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incentive Compensation Plan, termination period, in years	10 years
Common stock that will be made available for sale, in shares	3.0
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock purchase plan percentage of purchase price on closing price	85.00%
Shares issued Employee Stock Purchase Plan	0.5	0.6	0.5
Shares reserved for future issuances	8.5
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant-date fair value			$ 56.65
Total fair value of shares distributed	$ 62.7	$ 57.2	$ 49.1
Shares vested but not distributed	0.9
RSUs and PRSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost related to unvested RSUs and PRSUs that is expected to be recognized over a weighted-average period, Years	1 year 10 months 24 days
Weighted average grant-date fair value	$ 63.73	$ 67.65
Amended Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement, term of plan	Jul. 01, 2032
Incentive Compensation Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock that will be made available for sale, in shares				4.3
Amended Incentive Compensation Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock that will be made available for sale, in shares				6.5