Supplementary Information Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Millions		Sep. 30, 2019		Jun. 01, 2019	Dec. 31, 2018	Sep. 30, 2018		Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents		$ 1,980			$ 2,270	$ 1,657
Restricted Cash				$ 319
Cash and cash equivalents of discontinued operations		0			2,254	1,965
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Total Company		2,400	[1]		5,024	4,128	[1]	$ 7,914
Other Current Assets [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash		420			460	462
Restricted cash of discontinued operations	[2],[3]	0			40	44
Continuing Operations [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash, Cash Equivalents, and Restricted Cash, Continuing Operations		$ 2,400			$ 2,730	$ 2,119

[1] See page 27 for reconciliation of cash and cash equivalents and restricted cash presented in Condensed Consolidated Balance Sheets to total cash, cash equivalents and restricted cash presented in the Condensed Consolidated Statements of Cash Flows.

[2] Amount included in other current assets within assets of discontinued operations - current. Refer to Note 5 - Divestitures and Other Transactions, for additional information.

[3] Refer to Note 5 - Divestitures and Other Transactions, for additional information.