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Incentive Plans (Tables) | 12 Months Ended
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Dec. 31, 2011
Incentive Plans [Abstract] |
Summary of activity in outstanding grants |
Outstanding grants at the beginning of the period |  |  | 753,868 |
Grants during the period |  |  | 279,078 |
Grants vested and paid during the period |  |  | (162,186 | )
Forfeitures during the period |  |  | (416 | )
Outstanding grants at the end of the period |  |  | 870,344 |

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- Definition Summary of long term incentive plan disclosure. + References No definition available. + Details
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