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Earnings Per Share (Schedule of Earnings Per Share, Basic And Diluted) (Details) - USD ($) | 3 Months Ended
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Mar. 31, 2018 | Mar. 31, 2017
Numerators: |  |
Numerator for both basic and diluted EPS, net income | $ 111,248,743 | $ 97,556,741
Denominators: |  |
Denominator for basic EPS, weighted-average shares outstanding (in shares) | 274,759,516 | 287,408,900
Potentially dilutive shares resulting from stock plans (in shares) | 2,749,912 | 4,070,938
Denominator for diluted EPS (in shares) | 277,509,428 | 291,479,838
Shares related to stock plans not included in diluted average common shares outstanding because their effect would be anti-dilutive (in shares) | 156,467 | 2,311

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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/presentationRef -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 The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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