Quarterly report pursuant to Section 13 or 15(d)

Escrow Deposits (Details)

v2.4.1.9
Escrow Deposits (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 1 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Feb. 28, 2015
helicopter
Dec. 31, 2014
Significant Acquisitions and Disposals [Line Items]        
Escrow deposits $ 2,800us-gaap_EscrowDeposit     $ 0us-gaap_EscrowDeposit
Proceeds from disposition of property and equipment 5,379us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment 3,566us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment    
Light Twin Helicopter [Member]        
Significant Acquisitions and Disposals [Line Items]        
Number of disposals     1era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightTwinHelicopterMember
 
Proceeds from disposition of property and equipment     $ 2,800us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightTwinHelicopterMember