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Contingencies - Additional Information (Detail) (CAD) In Billions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2012
Amount related to damages | 3.5
KS Centoco Ltd [Member] |
Number of subsidiaries sued by KS Centoco Ltd | 2
Percentage of equity interest owned by company | 23.00%
Percentage of equity interest owned by third party | 77.00%
MST Automotive Inc [Member] |
Percentage of equity interest owned by company | 77.00%
Percentage of equity interest owned by third party | 23.00%

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