Assets and Liabilities Related to Superior and Meraux Refineries and Associated Marketing Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2010 Superior and Meraux Refineries
Current assets:
Accounts receivable	$ 1,554,184	$ 1,467,311	$ 1,191
Liquid inventories			115,014
Materials and supplies inventories			39,853
Total current assets	3,447,671	3,550,693	156,058
Noncurrent assets:
Property, plant and equipment, net of accumulated depreciation, depletion and amortization	10,475,149	10,367,847	723,980
Other	173,455	271,853	48,604
Total noncurrent assets - U.S. refineries			772,584
Total assets	14,138,138	14,233,243	928,642
Liabilities:
Current liabilities	2,824,928	2,930,910	2,637
Other noncurrent liabilities	439,604	395,972	14,133
Liabilities associated with assets sold - U.S. refineries			$ 16,770