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Summary of Significant Accounting Policies (Tables) | 6 Months Ended
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Jun. 30, 2015
Accounting Policies [Abstract] |
Awards outstanding [Table Text Block] | The following table presents the number of shares or units outstanding for each award type as of June 30, 2015 and December 31, 2014, respectively, (in thousands):
Award type |  | June 30, 2015 |  | December 31, 2014
Stock options |  | 868 |  |  | 961 |
Restricted stock units (time based) |  | 2,104 |  |  | 1,830 |
Restricted stock units (performance based) |  | 32 |  |  | 34 |
Stock appreciation rights |  | 606 |  |  | 673 |
Market stock units |  | 563 |  |  | 444 |
Market Stock Units Valuation Assumptions [Table Text Block] | The weighted average assumptions used to value the MSUs granted during the three and six months ended June 30, 2015 were as follows:
|  | June 30, 2015
Volatility |  | 42.06%
Risk-free interest rate |  | 0.89%
Expected option life in years |  | 2.95
Dividend yield |  | —

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- Definition Schedule of awards outstanding for each share-based compansation award type. + References No definition available. + Details
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- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of Market Stock Units which are performance-based awards that vest based upon the Company's relative shareholder return. + References No definition available. + Details
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