Earnings Per Share (Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Net income | |||||||||||
| Net income | $ 43,520 | $ 20,158 | $ 26,445 | $ 28,585 | $ 59,710 | $ 34,208 | $ 41,632 | $ 33,689 | $ 118,708 | $ 169,239 | $ 172,984 |
| Weighted average number of shares outstanding: | |||||||||||
| Basic (shares) | 52,359 | 52,627 | 52,736 | ||||||||
| Dilutive effect of stock-based compensation awards (shares) | 504 | 878 | 897 | ||||||||
| Diluted (shares) | 52,863 | 53,505 | 53,633 | ||||||||
| Earnings Per Share, Basic and Diluted [Abstract] | |||||||||||
| Basic (usd per share) | $ 0.83 | $ 0.39 | $ 0.50 | $ 0.55 | $ 1.14 | $ 0.65 | $ 0.79 | $ 0.64 | $ 2.27 | $ 3.22 | $ 3.28 |
| Diluted (usd per share) | $ 0.82 | $ 0.38 | $ 0.50 | $ 0.54 | $ 1.12 | $ 0.64 | $ 0.78 | $ 0.63 | $ 2.25 | $ 3.16 | $ 3.23 |
| Unexercised employee stock options and stock appreciation rights and unvested restricted stock units excluded from the diluted EPS calculation because their effect would have been antidilutive | 2,076 | 560 | 763 | ||||||||
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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