Contingencies and Commitments - Litigation (Details) - Louisiana Parishes Coastal Erosion Cases - FCX affiliates	Dec. 31, 2019 case
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number	42
Number of Parishes That Filed Claims	6
Settled litigation
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number	13

Number of pending claims pertaining to a loss contingency.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant