Long-Term Employee Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 01, 2013
Other Long-Term Employee Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Pre-tax net loss that will be amortized from accumulated other comprehensive income in next fiscal year	$ 69
Pre-tax prior service cost/(credit) that will be amortized from accumulated other comprehensive income in next fiscal year	$ (156)
Discount rate	4.13%	4.60%	3.85%
Expected return on plan assets	0.00%	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%	4.40%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Charge related to prior period settlements	$ 32
Charge related to prior period settlements, after-tax	21
Accumulated other comprehensive loss revision for pension settlement charges				$ 54
Accumulated benefit obligation	24,984	$ 27,923
Pre-tax net loss that will be amortized from accumulated other comprehensive income in next fiscal year	689
Pre-tax prior service cost/(credit) that will be amortized from accumulated other comprehensive income in next fiscal year	$ (6)
Discount rate	3.93%	4.55%	3.90%
Expected return on plan assets	8.10%	8.35%	8.39%
Rate of compensation increase	4.01%	4.22%	4.14%
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.29%	4.90%	4.10%
Expected return on plan assets	8.50%	8.75%	8.75%
Rate of compensation increase	4.20%	4.50%	4.40%