Employee Benefits (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Maximum annual increase percentage to company contribution for retiree medical coverage	4.00%
Defined benefit plan, estimated future employer contributions in next fiscal year beginning after the date of the latest statement of financial position			$ 1,000
Defined benefit plan, contributions by employer to employee pension plan		961
Defined benefit plan, expected contributions in current fiscal year		1,200
Contribution to other post retirement plans		151
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to other post retirement plans		77
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, estimated future employer contributions in next fiscal year beginning after the date of the latest statement of financial position			650
Defined benefit plan, contributions by employer to employee pension plan		809
Defined benefit plan, expected contributions in current fiscal year		850
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, estimated future employer contributions in next fiscal year beginning after the date of the latest statement of financial position			350
Defined benefit plan, expected contributions in current fiscal year		$ 350