Other Income and Expense (Other Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Schedule of other operating expense [Line Items]
Gain (Loss) on Disposition of Assets	$ (27)		$ (43)	$ (38)
Allowance for other receivables	7		0	52	[1]
Loss On Sale And Disposal Of Assets	30	[2]	28	12
Water Rights Write-Off	0		19	6
Other	11		10	7
Defined Benefit Plan, Other Cost (Credit)	10		1	3
Other Expenses	58		$ 58	$ 80
Other Expense [Member]
Schedule of other operating expense [Line Items]
Gain (Loss) on Disposition of Assets	$ 20

[1] During the fourth quarter of 2016, we recognized a full allowance on a non-trade receivable in the MCAC SBU as a result of payment delays and discussions with the counterparty. The allowance was related to certain reimbursements the Company was expecting in connection with a legal matter.

[2] In September 2018, the Company recorded a $20 million loss due to damage associated with a lightning incident at the Andres facility in the Dominican Republic