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Accounting policies (Tables) | 12 Months Ended
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Dec. 31, 2012
Accounting Policies [Abstract] |
Schedule of range of estimated service lives |
Buildings |  |  | 10 – 45 Years |
Machinery and equipment |  |  | 7 – 35 Years |
Other |  |  | 4 – 40 Years |

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- Definition The range of estimated service lives used to calculate financial reporting depreciation for principal items of plant and equipment. + References No definition available. + Details
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