Accounts Receivable and Inventory (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts Receivable And Inventory (Textuals) [Abstract]
Allowance for doubtful accounts receivable	$ 79	$ 85
Percentage of inventory at FIFO accounted for using the LIFO method	45.00%	43.00%
Inventory Disclosure [Abstract]
Raw materials	955	915
Work-in-process	428	423
Finished goods	1,115	1,131
Inventory at FIFO	2,498	2,469
Excess of FIFO over LIFO cost	(116)	(133)
Total inventory	$ 2,382	$ 2,336