Basis of presentation (Policies)	12 Months Ended
Dec. 31, 2011
Basis of presentation [Abstract]
Principles of consolidation	Principles of consolidation The consolidated financial statements include the accounts of MGIC Investment Corporation and its majority-owned subsidiaries. All intercompany transactions have been eliminated.

Basis of presentation (Policies)

12 Months Ended

Dec. 31, 2011

The consolidated financial statements include the accounts of MGIC Investment Corporation and its majority-owned subsidiaries. All intercompany transactions have been eliminated.

- Definition

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.

+ References

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+ Details