Basis of Presentation (Policies)	6 Months Ended
Jun. 30, 2012
Accounting Policies [Abstract]
Principles of Consolidation	The consolidated financial statements include the accounts of OMG and its consolidated subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation.

Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

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