Recent Accounting Guidance Lease ASU - Balance Sheet Impact of Adoption (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018		Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment - net	$ 4,503		$ 4,544	[1]	$ 4,384
Other assets	2,440		1,932	[1]	1,888
Assets of discontinued operations - non-current	0		56,545		57,185
Assets of discontinued operations - current	0		9,089	[1]	9,055
Short-term borrowings and finance lease obligations	3,604		2,154	[1]	4,371
Accrued and other current liabilities	2,249		4,005	[1]	2,117
Liabilities of discontinued operations - current	0		3,167	[1]	2,888
Long-term Debt	116		5,784	[1]	10,215
Other noncurrent obligations	2,132		1,795	[1]	1,799
Liabilities of discontinued operations - non-current	$ 0		$ 5,484		$ 5,532
Effect of Adoption of ASU 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment - net		$ 9
Other assets		546
Assets of discontinued operations - non-current		461
Short-term borrowings and finance lease obligations		1
Accrued and other current liabilities		143
Liabilities of discontinued operations - current		141
Long-term Debt		8
Other noncurrent obligations		403
Liabilities of discontinued operations - non-current		320
Updated
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment - net		4,553
Other assets		2,478
Assets of discontinued operations - non-current		57,006
Short-term borrowings and finance lease obligations		2,155
Accrued and other current liabilities		4,148
Liabilities of discontinued operations - current		3,308
Long-term Debt		5,792
Other noncurrent obligations		2,198
Liabilities of discontinued operations - non-current		$ 5,804

[1] Includes adjustments for discontinued operations and common control business combination.