Segment Information (Balance Sheet) (Details) (USD $) | Sep. 30, 2011 | Dec. 31, 2010 | Sep. 30, 2010 | |||
|---|---|---|---|---|---|---|
| Current assets | $ 9,607,000,000 | [1] | $ 5,555,000,000 | |||
| Property and equipment, net | 23,170,000,000 | 19,652,000,000 | ||||
| Goodwill | 5,951,000,000 | 6,080,000,000 | ||||
| Other assets | 1,138,000,000 | |||||
| Total assets | 39,866,000,000 | 32,927,000,000 | ||||
| Current liabilities | 6,031,000,000 | 4,583,000,000 | ||||
| Long-term debt | 5,969,000,000 | 3,819,000,000 | ||||
| Asset retirement obligations | 1,460,000,000 | 1,423,000,000 | 1,394,000,000 | |||
| Other liabilities | 495,000,000 | |||||
| Deferred income taxes | 4,809,000,000 | 2,756,000,000 | ||||
| Stockholders' equity | 21,102,000,000 | 19,253,000,000 | ||||
| Total liabilities and stockholders' equity | 39,866,000,000 | 32,927,000,000 | ||||
| Cash, Cash Equivalents, and Short-term Investments | 6,800,000,000 | |||||
Canada [Member] | ||||||
| Current assets | 7,025,000,000 | [1] | ||||
| Property and equipment, net | 7,531,000,000 | |||||
| Goodwill | 2,905,000,000 | |||||
| Other assets | 365,000,000 | |||||
| Total assets | 17,826,000,000 | |||||
| Current liabilities | 660,000,000 | |||||
| Long-term debt | 1,235,000,000 | |||||
| Asset retirement obligations | 867,000,000 | |||||
| Other liabilities | 67,000,000 | |||||
| Deferred income taxes | 1,323,000,000 | |||||
| Stockholders' equity | 13,674,000,000 | |||||
| Total liabilities and stockholders' equity | 17,826,000,000 | |||||
| Cash, Cash Equivalents, and Short-term Investments | 6,100,000,000 | |||||
US [Member] | ||||||
| Current assets | 2,556,000,000 | [1] | ||||
| Property and equipment, net | 15,639,000,000 | |||||
| Goodwill | 3,046,000,000 | |||||
| Other assets | 662,000,000 | |||||
| Total assets | 21,903,000,000 | |||||
| Current liabilities | 5,321,000,000 | |||||
| Long-term debt | 4,734,000,000 | |||||
| Asset retirement obligations | 593,000,000 | |||||
| Other liabilities | 426,000,000 | |||||
| Deferred income taxes | 3,486,000,000 | |||||
| Stockholders' equity | 7,343,000,000 | |||||
| Total liabilities and stockholders' equity | 21,903,000,000 | |||||
International [Member] | ||||||
| Current assets | 26,000,000 | [1] | ||||
| Other assets | 111,000,000 | |||||
| Total assets | 137,000,000 | |||||
| Current liabilities | 50,000,000 | |||||
| Other liabilities | 2,000,000 | |||||
| Stockholders' equity | 85,000,000 | |||||
| Total liabilities and stockholders' equity | $ 137,000,000 | |||||
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- Definition Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise separates deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets are classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, are classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total of all Liabilities and Stockholders' Equity items (or Partners' Capital, as applicable), including the portion of equity attributable to noncontrolling interests, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The aggregate carrying amounts, as of the balance sheet date, of assets not separately disclosed in the balance sheet. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The aggregate carrying amount, as of the balance sheet date, of liabilities not separately disclosed in the balance sheet. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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