Net Earnings Per Share Net Earnings Per Share (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Income (loss) Available to Common Stockholders, Basic	$ 60,663	$ 62,047	$ 137,344	$ 169,913
Weighted Average Number of Shares Outstanding, Basic	131,125	134,741	131,848	135,264
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	558	1,309	993	1,562
Weighted Average Number of Shares Outstanding, Diluted	131,683	136,050	132,841	136,826

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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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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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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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