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Basis of Presentation - Additional Information (Detail) | Dec. 31, 2012 | Dec. 31, 2011
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Basis Of Presentation [Line Items] |  |
Ownership interest of sole general partner | 95.50% | 94.30%
Ownership interest of limited partners | 4.50% | 5.70%

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- Details
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- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
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- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
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