Basis of Presentation (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Summary of Reclassification From Prior Period [Line Items]
Prepaid pension	$ 720		$ 1,033
Reclassification adjustment, amount transferred from operating activities to issuance of shares for employee benefit plans in financing activities		$ 213
Reclassification adjustment, amount transferred from account payable and accrued liabilities in operating activities to financing activities		150
Reclassification Adjustment, amount transferred from other assets and liabilities in operating activities to financing activities		63
Noncontrolling interests and other financing activities	$ (62)	(23)
Dividends paid to noncontrolling interests		(18)
Restructuring reserve		(19)
Scenario, Previously Reported [Member]
Summary of Reclassification From Prior Period [Line Items]
Noncontrolling interests and other financing activities		$ (5)