Earnings Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted Earnings Per Computations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Numerator / net income
Income and shares used in basic calculations	$ 3,212	$ 37,165
Denominator / shares
Income and shares used in basic calculations (in shares)	66,306	88,458
Income and shares used in diluted calculations (in shares)	67,642	89,605
Basic earnings per share (in dollars per share)	$ 0.05	$ 0.42
Diluted earnings per share (in dollars per share)	$ 0.05	$ 0.41
Restricted awards
Denominator / shares
Effect of dilutive stock based awards (in shares)	800	992
Stock options and SARs
Denominator / shares
Effect of dilutive stock based awards (in shares)	536	155

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Numerator [Abstract]

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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.

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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.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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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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- 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.

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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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