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Share Transactions - Share repurchases (Details) - Common shares shares in Millions, $ in Millions | 9 Months Ended
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Sep. 30, 2022 USD ($) shares
Class of Stock [Line Items] |
Cumulative number of shares acquired since inception of share repurchase program | shares | 433.6
Aggregate purchase price of shares acquired since inception of share repurchase program | $ 5,870.0
Treasury stock, shares acquired (shares) | shares | 12.9
Shares repurchased for treasury | $ 585.8
Remaining authorized repurchase amount | $ 596.4

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