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Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended				9 Months Ended		110 Months Ended
	Oct. 22, 2025	Jul. 29, 2016	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, repurchased cost			$ 27.3			$ 15.1	$ 79.7	$ 40.4
O 2025 Q1 Dividends [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared					$ 0.308
Dividends payable, date to be paid, year and month					2025-03
O 2025 Q2 Dividends [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared				$ 0.308
Dividends payable, date to be paid, year and month				2025-05
O 2025 Q3 Dividends [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared			$ 0.308
Dividends payable, date to be paid, year and month			2025-08				2025-08		2025-08
O 2025 Q4 Dividends [Member] \| Forecast [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared	$ 0.339
Dividends payable, date to be paid, year and month	2025-11
Common Stock [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, expiration date		Dec. 31, 2026
Stock repurchase program, remaining authorized repurchase amount			$ 582.8				$ 582.8		$ 582.8
Shares repurchase program, shares repurchased			(149,230)			(125,992)	(505,935)	(352,385)
Common Stock [Member] \| Share Repurchase Program Excluding Accelerated Share Repurchase [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, shares repurchased			100,000				500,000
Shares repurchase program, repurchased cost			$ 27.0				$ 79.0
Shares repurchase program, average price per share			$ 181.19				$ 156.22
Common Stock [Member] \| Share Repurchase Program Including Accelerated Share Repurchase [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, shares repurchased									15,100,000
Shares repurchase program, repurchased cost									$ 1,117.2
Shares repurchase program, average price per share									$ 73.74
Common Stock [Member] \| July 2018 Program [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, authorized amount		$ 150.0
Common Stock [Member] \| December 2026 Program [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, authorized amount		$ 1,700.0