Guarantees, Contingencies and Commitments (Tables)

12 Months Ended

Dec. 31, 2018

Commitments And Contingencies Disclosure [Abstract]

Schedule of Unconditional Purchase Obligations and Commitments

The following table shows aggregate information for certain unconditional purchase obligations and commitments at December 31, 2018, which are not included elsewhere within these Consolidated Financial Statements:

			Payments Due by Period
					2020 and		2022 and
	Total		2019		2021		2023		Thereafter
	(In millions)
Capital expenditures	$	1,069	$	443	$	551	$	75	$	—
Operating expenses		433		219		99		61		54
Transportation and related contracts		1,050		212		401		336		101