Annual report pursuant to Section 13 and 15(d)

Series A Preferred Stock (Details)

v2.4.1.9
Series A Preferred Stock (Details) (Series A Preferred Stock [Member], USD $)
In Millions, except Share data, unless otherwise specified
0 Months Ended
Dec. 23, 2011
Jan. 31, 2013
Dec. 23, 2011
Jul. 31, 2011
Series A Preferred Stock [Member]
       
Class of Stock [Line Items]        
Preferred stock, shares authorized (in shares)       10,000,000us-gaap_PreferredStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, par value $ 100us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
  $ 100us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
$ 0.01us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, shares issued (in shares) 1,400,000us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
  1,400,000us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
 
Exchange of advances from SEACOR for Series A Preferred Stock $ 140.0era_ExchangeofAdvancesfromAffiliateforPreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
     
Shares exchanged (in shares)   1,400,000era_PreferredStockSharesExchanged
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember