Restructuring and Other Charges (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges	$ 252	$ 846	$ 156
Severance charges		41	46
Tax (expense)/benefit	$ (466)	$ (123)	$ 498
Restructuring and related cost, number of positions eliminated	69	957	1,384
Cellulosic Bio Fuel Tax Credit [Member]
Restructuring Cost and Reserve [Line Items]
Tax (expense)/benefit		$ 753