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Earnings Per Share (Details) - shares | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Mar. 31, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Class of Stock [Line Items] |  |  |  |  |
Weighted average common shares outstanding for basic calculation (shares) | 267,265,705 |  | 290,112,233 | 267,908,427 | 290,410,859
Add: Effect of stock options, deferred stock units and restricted stock units (shares) | 13,850 |  | 15,063 | 12,463 | 11,492
Weighted average common shares outstanding for diluted calculation (shares) | 267,279,555 |  | 290,127,296 | 267,920,890 | 290,422,351
Participating securities (shares) | 77,157 |  | 36,546 | 65,264 | 28,914
Anti-dilutive shares (shares) | 1,730,960 |  | 1,303,854 | 1,644,002 | 1,203,220
Common Stock |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Stock Repurchased and Retired During Period, Shares |  | 3,328,574 | 879,134 | 3,328,574 | 0

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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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1707-109256 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 28A -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1500-109256 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 23 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1757-109256 + Details
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