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           NATURE OF OPERATIONS AND ACCOUNTING POLICIES Nature of Operations Narrative (Details) (USD $) 
        In Millions, except Share data, unless otherwise specified  | 
        0 Months Ended | |
|---|---|---|
| 
           Jan. 31, 2013 
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           Jan. 31, 2013
 
          stock_class 
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| Recapitalization [Line Items] | ||
| Newly issued common stock | 19,883,583us-gaap_StockIssuedDuringPeriodSharesNewIssues | |
| Common stock, par value | $ 0.01us-gaap_CommonStockParOrStatedValuePerShare | $ 0.01us-gaap_CommonStockParOrStatedValuePerShare | 
| Number of stock classes | 1era_NumberofClassesofStock | 1era_NumberofClassesofStock | 
| Series A Preferred Stock [Member] | ||
| Recapitalization [Line Items] | ||
| Value of preferred stock outstanding | 
$ 140.0us-gaap_PreferredStockValueOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_SeriesAPreferredStockMember  | 
        
$ 140.0us-gaap_PreferredStockValueOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_SeriesAPreferredStockMember  | 
      
| Preferred stock percentage | 
6.00%us-gaap_PreferredStockDividendRatePercentage / us-gaap_StatementClassOfStockAxis = us-gaap_SeriesAPreferredStockMember  | 
        
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- Definition 
          Number of Classes of Stock No definition available. 
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- Details 
          
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- Definition 
          Face amount or stated value per share of common stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The percentage rate used to calculate dividend payments on preferred stock. No definition available. 
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- Definition 
          Value of all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by shareholders, which is net of related treasury stock. May be all or a portion of the number of preferred shares authorized. These shares represent the ownership interest of the preferred shareholders. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          Number of new stock issued during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
          
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