Restructuring and Reorganization Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Before tax charge	$ 353
After tax charge	223
Payments for Restructuring	60
Restructuring Reserve [Roll Forward]
Balance at January 1, 2015	0
Accruals/Adjustments	353
Payments	(60)
Balance at December 31, 2015	293
Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Before tax charge	134
After tax charge	87
United States [Member] | Upstream [Member]
Restructuring Cost and Reserve [Line Items]
Before tax charge	113
After tax charge	73
International [Member] | Upstream [Member]
Restructuring Cost and Reserve [Line Items]
Before tax charge	106
After tax charge	63
Operating Expense [Member]
Restructuring Cost and Reserve [Line Items]
Before tax charge	219
Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Before tax charge	$ 134