Benefit Plans (Amounts Recognized in the Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
AMOUNTS RECOGNIZED ON THE CONSOLIDATED BALANCE SHEETS
Accrued benefit liability—noncurrent	$ (1,396)	$ (919)
U.S. Defined Benefit Plans
AMOUNTS RECOGNIZED ON THE CONSOLIDATED BALANCE SHEETS
Noncurrent assets	0	0
Accrued benefit liability—current	0	0
Accrued benefit liability—noncurrent	(144)	(151)
Net amount recognized at end of year	(144)	(151)
Foreign Defined Benefit Plans
AMOUNTS RECOGNIZED ON THE CONSOLIDATED BALANCE SHEETS
Noncurrent assets	60	67
Accrued benefit liability—current	(5)	(5)
Accrued benefit liability—noncurrent	(1,223)	(743)
Net amount recognized at end of year	$ (1,168)	$ (681)