Disposals And Impairments of Long-Lived Assets (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Gain (loss) on impairment of assets	$ 6,621	$ (9,497)	$ (105,050)
Gain (loss) on goodwill impairment		(47,804)	(61,173)
Corporate and other [Member]
Gain (loss) on impairment of assets			(91,756)	[1]
SemCrude [Member]
Loss on deconsolidation			(6,828)	[2]
SemMexico [Member]
Gain (loss) on goodwill impairment			$ (8,863)	[3]

[1] During the year ended December 31, 2010, we revised downward our projections of the future earnings potential of the SemCanada Crude segment, following a significant loss of customers, coupled with a significant decline in profitability and an assessment by a national consultancy firm that certain market conditions that are adversely impacting this segment were likely to continue. In response to these events, we tested SemCanada Crude’s goodwill and other intangible assets for impairment as of May 31, 2010.During December 2010, we completed the sale of the property, plant and equipment of the SemCanada Crude segment. The proceeds from the sale were not significantly different than the net book value of the assets sold. Certain marketing operations in the Northern United States that were previously conducted with the participation of the SemCanada Crude segment are now being conducted in their entirety by the Crude segment, and the remaining operations of the SemCanada Crude segment were wound down.

[2] As described in Note 5, we sold a portion of our ownership interests in White Cliffs during September 2010. We received $140.8 million of proceeds from these transactions, which were used to make principal payments on long-term debt. The net assets of White Cliffs prior to the deconsolidation were as follows (in thousands):Accounts receivable$4,625Other current assets143Property, plant and equipment, net237,506Goodwill17,000Other intangible assets43,267Accounts payable and accrued liabilities(3,736)Payables to affiliates(659)Net assets$298,146

[3] We test goodwill for impairment as of October 1 of each year. Upon completing this impairment test for 2010, we concluded that the goodwill attributable to our SemMexico segment was impaired, due primarily to a decline in demand for asphalt resulting from a slowdown in road construction. To calculate the impairment loss, we estimated the fair value of the SemMexico segment using the present value of estimated future cash flows, discounted at a rate of 13.84%.