Fair Value Measurements, Nonrecurring (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Assets:
Asset impairment loss	$ 611,000,000	$ 0
Fair Value Measurements (Textual)
Long-lived assets, carrying value	25,155,000,000		25,177,000,000
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements (Textual)
Assets, nonrecurring			0
Liabilities, nonrecurring	0		0
Aruba Refinery [Member]
Assets:
Long-lived assets, fair value	350,000,000
Asset impairment loss	595,000,000
Fair Value Measurements (Textual)
Long-lived assets, carrying value	945,000,000
Aruba Refinery [Member] | Fair Value, Measurements, Nonrecurring [Member]
Assets:
Long-lived assets, fair value	350,000,000
Aruba Refinery [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Long-lived assets, fair value	0
Aruba Refinery [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Long-lived assets, fair value	0
Aruba Refinery [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Long-lived assets, fair value	350,000,000
Construction in Progress [Member]
Assets:
Asset impairment loss	16,000,000
Construction in Progress [Member] | Fair Value, Measurements, Nonrecurring [Member]
Assets:
Long-lived assets, fair value	2,000,000
Construction in Progress [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Long-lived assets, fair value	0
Construction in Progress [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Long-lived assets, fair value	0
Construction in Progress [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Long-lived assets, fair value	$ 2,000,000