Shareholders' Equity Share Repurchase (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
Mar. 31, 2020	May 31, 2019
Shareholders' Equity [Abstract]
Stock Repurchase Program, Authorized Amount		$ 1,000.0
Stock Repurchased and Retired During Period, Shares	8.1
Stock Repurchased and Retired During Period, Value	$ 126.9
Cumulative shares repurchased under share repurchase program	13.8
Cumulative treasury stock, retired, cost method, amount	$ 317.1

Number of shares that have been repurchased and retired during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Period Type:	duration