Schedule II - Valuation and Qualifying Accounts and Allowances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015		Jun. 30, 2017
Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts Receivable, Net of Allowance for Uncollectible Accounts of $156 in 2017 and $129 in 2016	$ 1,103	$ 1,383
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
of Period	129	113	$ 108
Expense (a)	238	69	48
Additions	0	0	1
Reductions (b) (c)	(38)	(53)	(42)
Period	329	129	113
Valuation allowance on deferred tax assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
of Period	1,738	868	732
Expense (a)	158	872	159
Additions	0	0	0
Reductions (b) (c)	(9)	(2)	(23)	[1]
Period	1,887	1,738	$ 868
VENEZUELA | Other Noncurrent Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts Receivable, Net of Allowance for Uncollectible Accounts of $156 in 2017 and $129 in 2016					$ 158
Allowance for Doubtful Accounts Receivable	158
Short [Member] | Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
of Period	129
Expense (a)	80
Additions	0
Reductions (b) (c)	(53)
Period	156	129
Long [Member] | Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
of Period	0
Expense (a)	158
Additions	0
Reductions (b) (c)	15
Period	$ 173	$ 0

[1] in 2017 for valuation allowance on deferred taxes primarily due to currency translation.All oth