Common Shares - Additional Information (Detail) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Class of Stock [Line Items]
Normal course issuer bid share repurchase shares authorized	1
Normal course issuer bid share repurchase programs	18
Normal course issuer bid share repurchase term, months	12 months
Exxon Mobil Corporation's ownership interest in Imperial	69.60%

Period which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration