Fair Value Measurements (Details-Recurring) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	$ 90
Derivative Liabilities	3
Commodity [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	48
Derivative Liabilities	2
Interest rate [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	22
Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	20
Derivative Liabilities	1
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	0
Fair Value, Inputs, Level 1 [Member] | Commodity [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	0
Fair Value, Inputs, Level 1 [Member] | Interest rate [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Fair Value, Inputs, Level 1 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	0
Fair Value Inputs Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	89
Derivative Liabilities	3
Fair Value Inputs Level 2 [Member] | Commodity [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	47
Derivative Liabilities	2
Fair Value Inputs Level 2 [Member] | Interest rate [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	22	5
Fair Value Inputs Level 2 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	20
Derivative Liabilities	1
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	0
Fair Value, Inputs, Level 3 [Member] | Commodity [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	0
Fair Value, Inputs, Level 3 [Member] | Interest rate [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	0
Fair Value (no inputs) Collateral [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	1
Derivative Liabilities	0
Fair Value (no inputs) Collateral [Member] | Commodity [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	1
Derivative Liabilities	0
Fair Value (no inputs) Collateral [Member] | Interest rate [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Fair Value (no inputs) Collateral [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Derivative Assets	0
Derivative Liabilities	$ 0