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Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended				9 Months Ended		122 Months Ended
	Oct. 21, 2026	Jul. 29, 2016	Sep. 30, 2026	Jun. 30, 2026	Mar. 31, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, repurchased cost			$ 75.8			$ 27.3	$ 211.9	$ 79.7
O 2026 Q1 Dividends [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared					$ 0.339
Dividends payable, date to be paid, year and month					2026-03
O 2026 Q2 Dividends [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared				$ 0.339
Dividends payable, date to be paid, year and month				2026-05
O 2026 Q3 Dividends [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared			$ 0.339
Dividends payable, date to be paid, year and month			2026-08				2026-08		2026-08
O 2026 Q4 Dividends Member \| Subsequent Event [Member]
Equity Class Of Treasury Stock [Line Items]
Quarterly dividends declared	$ 0.373
Dividends payable, date to be paid, year and month	2026-11
Common Stock [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, expiration date		Dec. 31, 2029
Stock repurchase program, remaining authorized repurchase amount			$ 1,122.9				$ 1,122.9		$ 1,122.9
Shares repurchase program, shares repurchased			(430,147)			(149,230)	(1,229,979)	(505,935)
Common Stock [Member] \| Share Repurchase Program Excluding Accelerated Share Repurchase [Member]
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program, shares repurchased			400,000				1,200,000		16,600,000
Shares repurchase program, repurchased cost			$ 75.0				$ 209.9		$ 1,377.1
Shares repurchase program, average price per share			$ 174.36				$ 170.65		$ 82.74
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		$ 2,500.0