For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Percent of net assets at close of period. For schedules of investments that are categorized, each category has a percent of net assets for the aggregated value of the Investments in the category.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 320
-Section S99
-Paragraph 1
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of the extent of enterprise reliance on its major customers. For example, includes revenues from transactions with a single external customer amounting to 10 percent or more of the entity's revenues, the total amount of revenues from each such customer, and the identity of the segment or segments reporting the revenues. A group of entities that the entity knows to be under common control generally will be considered a single customer for inclusion in this item. The federal government, a state government, a local government (for example, a county or municipality), or a foreign government each will generally be considered as a single customer for inclusion in this item.

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-Topic 280
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BUSINESS SEGMENTS INFORMATION (Customers and Labor Matters) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Major Customer and Labor Matters [Line Items]
Segment Reporting, Disclosure of Major Customers									0
Revenues	$ 4,377	$ 3,877	$ 3,334	$ 3,242	$ 3,516	$ 3,382	$ 3,938	$ 3,771	$ 14,830	$ 14,607	$ 20,001
Workforce Subject to Collective Bargaining Arrangements \| Labor Force Concentration Risk
Major Customer and Labor Matters [Line Items]
Concentration risk percentage									50.00%
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year \| Labor Force Concentration Risk
Major Customer and Labor Matters [Line Items]
Concentration risk percentage									33.00%
Affiliated Entity \| Noncontrolling Interest Owners Of South America Mining Operations
Major Customer and Labor Matters [Line Items]
Revenues									$ 1,000		1,600
Affiliated Entity \| PT Smelting
Major Customer and Labor Matters [Line Items]
Revenues									1,400	1,100	1,800
Phillips 66
Major Customer and Labor Matters [Line Items]
Revenues											$ 2,500
Phillips 66 \| Revenue \| Customer Concentration
Major Customer and Labor Matters [Line Items]
Concentration risk percentage											12.00%
Indonesia
Major Customer and Labor Matters [Line Items]
Revenues									$ 1,402	$ 1,054	$ 1,792
Indonesia \| PT Smelting
Major Customer and Labor Matters [Line Items]
Investment Owned, Percent of Net Assets	25.00%								25.00%