Long-Term Employee Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 27,923	$ 24,685
Pre-tax net loss that will be amortized from accumulated other comprehensive income in next fiscal year	838
Pre-tax prior service cost/(credit) that will be amortized from accumulated other comprehensive income in next fiscal year	(7)
Net periodic benefit costs, discount rate	4.55%	3.90%	4.32%
Net periodic benefit costs, expected return on plan assets	8.35%	8.39%	8.61%
Rate of compensation increase	4.22%	4.14%	4.18%
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit costs, discount rate	4.90%	4.10%	4.38%
Net periodic benefit costs, expected return on plan assets	8.75%	8.75%	8.96%
Rate of compensation increase	4.50%	4.40%	4.40%
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	76
Pre-tax prior service cost/(credit) that will be amortized from accumulated other comprehensive income in next fiscal year	$ (208)