Annual report pursuant to Section 13 and 15(d)

NATURE OF OPERATIONS AND ACCOUNTING POLICIES Revenue Recognition Narrative (Details)

v2.4.1.9
NATURE OF OPERATIONS AND ACCOUNTING POLICIES Revenue Recognition Narrative (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]        
Deferred revenue $ 31,047us-gaap_DeferredRevenue $ 24,243us-gaap_DeferredRevenue $ 8,953us-gaap_DeferredRevenue $ 123us-gaap_DeferredRevenue
Revenue recognized during period 25,338us-gaap_DeferredRevenueRevenueRecognized 22,646us-gaap_DeferredRevenueRevenueRecognized 17,078us-gaap_DeferredRevenueRevenueRecognized  
Service agreement cancellation period 30 days      
Aeroleo [Member]        
Schedule of Equity Method Investments [Line Items]        
Deferred revenue 31,000us-gaap_DeferredRevenue
/ us-gaap_MajorCustomersAxis
= era_AeroleoMember 		21,000us-gaap_DeferredRevenue
/ us-gaap_MajorCustomersAxis
= era_AeroleoMember 		   
Customer [Member]        
Schedule of Equity Method Investments [Line Items]        
Deferred revenue 0us-gaap_DeferredRevenue
/ us-gaap_MajorCustomersAxis
= era_CustomerMember 		3,200us-gaap_DeferredRevenue
/ us-gaap_MajorCustomersAxis
= era_CustomerMember 		   
Revenue recognized during period $ 1,700us-gaap_DeferredRevenueRevenueRecognized
/ us-gaap_MajorCustomersAxis
= era_CustomerMember 		     
Minimum [Member]        
Schedule of Equity Method Investments [Line Items]        
Service agreement period 1 month      
Hospital service agreement termination period 2 years      
Maximum [Member]        
Schedule of Equity Method Investments [Line Items]        
Service agreement period 5 years      
Hospital service agreement termination period 5 years