Related Party Transactions	6 Months Ended
Jun. 30, 2012
Related Party Transactions [Abstract]
Related Party Transactions	(10) Related Party Transactions BGP, Inc., China National Petroleum Corporation (“BGP”) owned approximately 15.3% of the Company’s outstanding common stock as of June 30, 2012. For the three and six months ended June 30, 2012, the Company recorded revenues from BGP of $4.1 million and $10.2 million, respectively, compared to revenues from BGP for the three and six months ended June 30, 2011 of $0.3 million and $1.3 million, respectively. Total receivables due from BGP were $5.2 million at June 30, 2012.

The entire disclosure for related party transactions, including the nature of the relationship(s), a description of the transactions, the amount of the transactions, the effects of any change in the method of establishing the terms of the transaction from the previous period, stated interest rate, expiration date, terms and manner of settlement per the agreement with the related party, and amounts due to or from related parties. If the entity and one or more other entities are under common ownership or management control and this control affects the operating results or financial position, disclosure includes the nature of the control relationship even if there are no transactions between the entities. Disclosure may also include the aggregate amount of current and deferred tax expense for each statement of earnings presented where the entity is a member of a group that files a consolidated tax return, the amount of any tax related balances due to or from affiliates as of the date of each statement of financial position presented, the principal provisions of the method by which the consolidated amount of current and deferred tax expense is allocated to the members of the group and the nature and effect of any changes in that method. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

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