Litigation, Environmental and Other Contingencies Environmental Matters (Details)						240 Months Ended
	Apr. 16, 2019	Mar. 29, 2019 Parties	May 04, 2018 USD ($) a	Dec. 18, 2015 USD ($)	Nov. 08, 2013 Parties	Dec. 31, 1969	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2015 cases
Loss Contingencies [Line Items]
Recorded Third-Party Environmental Recoveries Receivable | $							$ 12,000,000	$ 15,000,000
Percentage of Response Costs	35.00%
Rare Metals Inc.
Loss Contingencies [Line Items]
Number of Uranium Mines						20
Parish of Plaquemines, Louisiana | Coastal Zone | TGP
Loss Contingencies [Line Items]
Loss Contingency, Number of Defendants | Parties					17
Parish Orleans, Louisiana | Coastal Zone | SNG
Loss Contingencies [Line Items]
Loss Contingency, Number of Defendants | Parties		10
Judicial District of Louisiana | Coastal Zone
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number									40
Judicial District of Louisiana | Coastal Zone | TGP
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number									1
Judicial District of Louisiana | Coastal Zone | SNG
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number									1
Vintage Assets Inc. | Parish of Plaquemines, Louisiana | TGP and SNG
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value | $				$ 80,000,000
Restore acreage | a			9.6
Loss Contingency, Damages Awarded, Value | $			$ 1,104
Louisiana Landowner Coastal Erosion Litigation | Judicial District of Louisiana | TGP and SNG
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number									2
Louisiana Landowner Coastal Erosion Litigation | Judicial District of Louisiana | TGP
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number									2
Louisiana Landowner Coastal Erosion Litigation | Judicial District of Louisiana | SNG
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number									2