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Share Based Compensation (Tables) | 12 Months Ended
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Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] |
Weighted Average Fair Value and Assumptions | The following table shows the weighted average fair value for our stock appreciation rights and the assumptions we used to estimate fair value:
| 2014 |  | 2013 |  | 2012
Weighted average estimated fair value | $ | 18.12 |  |  | $ | 18.89 |  |  | $ | 18.48 |
Quarterly dividend rate | $ | 0.33 |  |  | $ | 0.30 |  |  | $ | 0.29 |
Expected term of stock appreciation rights, in years | 4.4 |  |  | 4.7 |  |  | 4.7 |
Risk-free interest rate | 1.3 | % |  | 0.7 | % |  | 1.0 | %
Dividend yield | 2.3 | % |  | 2.6 | % |  | 2.7 | %
Expected stock price volatility | 30.3 | % |  | 42.4 | % |  | 43.3 | %
Present value of dividends | $ | 5.76 |  |  | $ | 5.60 |  |  | $ | 5.37 |
Data With Respect to Stock Options SARs Activity | The following table shows information about outstanding stock options and stock appreciation rights for the year ended December 31, 2014:
| Number of Stock Options and Stock Appreciation Rights (in thousands) |  | Weighted Average Exercise Price
Outstanding at beginning of the year | 1,694 |  | $ | 36.03 |
Granted | 297 |  | 58.50 |
Exercised | (467) |  | 37.71 |
Forfeited/Cancelled | (33) |  | 50.71 |
Expired | (1) |  | 41.02 |
Outstanding at end of the year | 1,490 |  | 39.65 |
Vested and exercisable at end of the year | 919 |  | 32.08 |
Schedule of Share-Based Compensation, Aggregate Intrinsic Value and Weighted Average Remaining Contractual Term | The following table shows the aggregate intrinsic value of stock options and stock appreciation rights exercised in 2014, 2013, and 2012, and the weighted average remaining contractual term and aggregate intrinsic value of stock appreciation rights outstanding and vested as of December 31, 2014:
Stock Options and Stock Appreciation Rights | Weighted Average Remaining Contractual Term (Years) |  | Aggregate Intrinsic Value (in millions)
Exercised in 2012 |  |  | $ | 4.9 |
Exercised in 2013 |  |  | 6.9 |
Exercised in 2014 |  |  | 11.8 |
Outstanding at December 31, 2014 (a) | 3.7 |  | 27.5 |
Vested and exercisable at December 31, 2014 | 2.6 |  | 23.8 |
__________________ (a) As of December 31, 2014, there are no remaining stock options outstanding.
Schedule of Share-Based Compensation, Restricted Stock Units and Performance Shares Award Activity | The following table shows information about restricted stock units and performance shares for the year ended December 31, 2014:
| Number of Share Units Outstanding |  | Weighted Average Grant-Date Fair Value
Restricted Stock Units: |  |  |
Nonvested at beginning of the year | 200,050 |  |  | $ | 41.17 |
Granted | 56,020 |  |  | 58.66 |
Vested | (70,986 | ) |  | 34.77 |
Forfeited | (7,874 | ) |  | 49.42 |
Nonvested at end of the year | 177,210 |  |  | 48.90 |
Performance Shares: |  |  |
Nonvested at beginning of the year | 160,332 |  |  | $ | 44.48 |
Granted | 62,670 |  |  | 53.63 |
Net increase due to estimated performance | 67,392 |  |  | 47.49 |
Vested | (92,958 | ) |  | 44.02 |
Forfeited | (22,367 | ) |  | 46.57 |
Nonvested at end of the year | 175,069 |  |  | 48.95 |

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