Income and Other Taxes - Allocation of Income Tax Expense Benefit (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Income Tax Interperiod Allocaion [Line Items]
Pre-tax income		$ 481		$ 62	$ 193
Discontinued Operation, Tax Effect of Discontinued Operation	[2]	(12)	[1]	(250)	(134)
Stock option and incentive plans, net		0		0	(18)
Total Income Tax Expense (Benefit)		538		(179)	115
Changes in defined benefit plans
Income Tax Interperiod Allocaion [Line Items]
Other comprehensive income (loss), tax		63		15	59
Cash flow hedges
Income Tax Interperiod Allocaion [Line Items]
Other comprehensive income (loss), tax		5		(8)	15
Translation adjustments
Income Tax Interperiod Allocaion [Line Items]
Other comprehensive income (loss), tax		$ 1		$ 2	$ 0

[1] Primarily reflects changes in estimates.

[2] Refer to Note 5 - Divestitures for additional information regarding discontinued operations.