Earnings Per Common Share (Calculations) (Details) - $ / shares	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share, Diluted [Abstract]
Weighted average common shares outstanding	236,700,000	249,800,000
Effect of dilutive securities:
Stock options	700,000	900,000
Other stock compensation plans	600,000	700,000
Potentially dilutive common shares	1,300,000	1,600,000
Adjusted weighted average common shares outstanding	238,000,000	251,400,000
Outstanding stock options excluded from the computation of diluted earnings per share due to their antidilutive effect	1,600,000.0	1,100,000.0
Common Stock, Dividends, Per Share, Cash Paid	$ 0.0048	$ 0.0045

Incremental Common Shares Attributable To Other Stock Compensation Plans

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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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Aggregate dividends paid during the period for each share of common stock outstanding.

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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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The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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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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