Earnings Per Share (Details) - shares	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Class of Stock [Line Items]
Weighted average common shares outstanding for basic calculation (shares)	269,216,820	290,559,025
Add: Effect of stock options, deferred stock units and restricted stock units (shares)	19,742	7,138
Weighted average common shares outstanding for diluted calculation (shares)	269,236,562	290,566,163
Participating securities (shares)	53,204	21,413
Anti-dilutive shares (shares)	1,297,661	981,330
Common Stock
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares	3,328,574

Participating Securities

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- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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