Annual report pursuant to Section 13 and 15(d)

SERIES B PREFERRED STOCK (Details)

v2.4.1.9
SERIES B PREFERRED STOCK (Details) (USD $)
12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 20, 2012
Dec. 18, 2012
Sep. 25, 2012
Jun. 08, 2012
Class of Stock [Line Items]              
Issuance of Series B preferred stock $ 0us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock $ 0us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock $ 100,000,000us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock        
Series B Convertible Preferred Stock [Member]              
Class of Stock [Line Items]              
Preferred stock, shares authorized (in shares)             300,000us-gaap_PreferredStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
Preferred Stock, Additional Shares Authorized           700,000era_PreferredStockAdditionalSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
 
Issuance of Series B preferred stock           100,000,000us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
 
Preferred stock, par value           $ 100us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
 
Stock Redeemed or Called During Period, Shares       500,000us-gaap_StockRedeemedOrCalledDuringPeriodShares
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
500,000us-gaap_StockRedeemedOrCalledDuringPeriodShares
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
   
Preferred Stock, Liquidation Preference, Value         50,000,000us-gaap_PreferredStockLiquidationPreferenceValue
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
   
Payments for Repurchase of Convertible Preferred Stock       50,000,000us-gaap_PaymentsForRepurchaseOfConvertiblePreferredStock
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember
     
Line of credit outstanding       $ 50,000,000us-gaap_LineOfCredit
/ us-gaap_StatementClassOfStockAxis
= era_ConvertibleSeriesBPreferredStockMember