New Accounting Standard (Unaudited)	9 Months Ended
Sep. 30, 2017
New Accounting Standards [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	NEW ACCOUNTING STANDARDS In May 2014, the Financial Accounting Standards Board (FASB) issued an Accounting Standard Update (ASU) that provides a single comprehensive revenue recognition model, which will replace most existing revenue recognition guidance, and also requires expanded disclosures. The core principle of the model is that revenue is recognized when control of goods or services has been transferred to customers at an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. For public entities, this ASU is effective for annual reporting periods beginning after December 15, 2017, and interim reporting periods within that reporting period. Early adoption is permitted for annual reporting periods beginning after December 15, 2016, and interim reporting periods within that reporting period. FCX will adopt this ASU January 1, 2018, and currently expects to apply the modified retrospective approach under which any cumulative effect adjustment would be recorded to retained earnings as of the adoption date. FCX has substantially completed its review of the impact of this guidance, and based on the terms of its sales contracts, does not expect the guidance to have any impact on its revenue recognition policies or processes. FCX continues to review the impact of the new guidance on its financial reporting and disclosures. In March 2016, FASB issued an ASU that simplifies various aspects of the accounting for share-based payment transactions, including the income tax consequences, statutory tax withholding requirements, an accounting policy election for forfeitures and the classification on the statement of cash flows. FCX adopted this ASU effective January 1, 2017, and adoption did not have a material impact on its financial statements. In March 2017, FASB issued an ASU that changes how entities with a defined benefit pension or other postretirement benefit plans present net periodic benefit cost in the income statement. This ASU requires the service cost component of net periodic benefit cost to be presented in the same income statement line item or items as other compensation costs for those employees who are receiving the retirement benefit. In addition, only the service cost component is eligible for capitalization when applicable (i.e., as a cost of inventory or an internally constructed asset). The other components of net periodic benefit cost are required to be presented separately from the service cost component and outside of operating income. These other components of net periodic benefit cost are not eligible for capitalization, and the income statement line item or items must be disclosed. For public entities, this ASU is effective for annual periods beginning after December 15, 2017, and interim reporting periods within that reporting period. Early adoption is permitted. FCX will adopt this ASU on January 1, 2018, and does not expect it to have a material impact on its presentation of the statements of operations.

NEW ACCOUNTING STANDARDS

In May 2014, the Financial Accounting Standards Board (FASB) issued an Accounting Standard Update (ASU) that provides a single comprehensive revenue recognition model, which will replace most existing revenue recognition guidance, and also requires expanded disclosures. The core principle of the model is that revenue is recognized when control of goods or services has been transferred to customers at an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. For public entities, this ASU is effective for annual reporting periods beginning after December 15, 2017, and interim reporting periods within that reporting period. Early adoption is permitted for annual reporting periods beginning after December 15, 2016, and interim reporting periods within that reporting period. FCX will adopt this ASU January 1, 2018, and currently expects to apply the modified retrospective approach under which any cumulative effect adjustment would be recorded to retained earnings as of the adoption date. FCX has substantially completed its review of the impact of this guidance, and based on the terms of its sales contracts, does not expect the guidance to have any impact on its revenue recognition policies or processes. FCX continues to review the impact of the new guidance on its financial reporting and disclosures.

In March 2016, FASB issued an ASU that simplifies various aspects of the accounting for share-based payment transactions, including the income tax consequences, statutory tax withholding requirements, an accounting policy election for forfeitures and the classification on the statement of cash flows. FCX adopted this ASU effective January 1, 2017, and adoption did not have a material impact on its financial statements.

In March 2017, FASB issued an ASU that changes how entities with a defined benefit pension or other postretirement benefit plans present net periodic benefit cost in the income statement. This ASU requires the service cost component of net periodic benefit cost to be presented in the same income statement line item or items as other compensation costs for those employees who are receiving the retirement benefit. In addition, only the service cost component is eligible for capitalization when applicable (i.e., as a cost of inventory or an internally constructed asset). The other components of net periodic benefit cost are required to be presented separately from the service cost component and outside of operating income. These other components of net periodic benefit cost are not eligible for capitalization, and the income statement line item or items must be disclosed. For public entities, this ASU is effective for annual periods beginning after December 15, 2017, and interim reporting periods within that reporting period. Early adoption is permitted. FCX will adopt this ASU on January 1, 2018, and does not expect it to have a material impact on its presentation of the statements of operations.