Annual report pursuant to Section 13 and 15(d)

ACQUISITIONS AND DISPOSITIONS (Details)

v2.4.1.9
ACQUISITIONS AND DISPOSITIONS (Details) (USD $)
In Thousands, unless otherwise specified
 1 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2014
May 31, 2014
helicopter
Dec. 31, 2014
helicopter
Dec. 31, 2013
helicopter
Dec. 31, 2012
helicopter
Property, Plant and Equipment [Line Items]          
Capital expenditures     106,732us-gaap_PaymentsToAcquirePropertyPlantAndEquipment 110,105us-gaap_PaymentsToAcquirePropertyPlantAndEquipment 112,986us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Proceeds from disposition of property and equipment     7,051us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment 65,151us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment 5,188us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
Equipment Additions (in helicopters)     4era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions 6era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions [1] 18era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions [2]
Equipment Dispositions (in helicopters)     3era_SignificantAcquisitionsAndDisposalsNumberOfDisposals 15era_SignificantAcquisitionsAndDisposalsNumberOfDisposals 8era_SignificantAcquisitionsAndDisposalsNumberOfDisposals [3]
Light Helicopters - Single Engine [Member]          
Property, Plant and Equipment [Line Items]          
Equipment Additions (in helicopters)     0era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember 		0era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember 		[1] 3era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember 		[2]
Equipment Dispositions (in helicopters)     0era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember 		0era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember 		0era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember 		[3]
Previously Leased-in (in helicopters)         3era_NumberofHelicoptersPreviouslyLeasedIn
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember
Previously Disposed (in helicopters)         1era_NumberOfHelicoptersPreviouslyDisposed
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersSingleEngineMember
Light Helicopters - Twin Engine [Member]          
Property, Plant and Equipment [Line Items]          
Equipment Additions (in helicopters)     0era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		2era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		[1] 4era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		[2]
Equipment Dispositions (in helicopters)     0era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		4era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		6era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		[3]
Previously Leased-in (in helicopters)       2era_NumberofHelicoptersPreviouslyLeasedIn
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember 		 
Removed from Service (in helicopters)         2era_NumberofHelicoptersRemovedfromService
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_LightHelicoptersTwinEngineMember
Medium Helicopter [Member]          
Property, Plant and Equipment [Line Items]          
Proceeds from disposition of property and equipment $ 3,000us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		$ 6,400us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		     
Equipment Additions (in helicopters)     4era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		4era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		[1] 8era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		[2]
Equipment Dispositions (in helicopters)   2era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		3era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		10era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		2era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		[3]
Previously Leased-in (in helicopters)       1era_NumberofHelicoptersPreviouslyLeasedIn
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember 		1era_NumberofHelicoptersPreviouslyLeasedIn
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_MediumHelicopterMember
Heavy Helicopter [Member]          
Property, Plant and Equipment [Line Items]          
Equipment Additions (in helicopters)     0era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_HeavyHelicopterMember 		0era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_HeavyHelicopterMember 		[1] 3era_SignificantAcquisitionsAndDisposalsNumberOfAcquisitions
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_HeavyHelicopterMember 		[2]
Equipment Dispositions (in helicopters)     0era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_HeavyHelicopterMember 		1era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_HeavyHelicopterMember 		0era_SignificantAcquisitionsAndDisposalsNumberOfDisposals
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= era_HeavyHelicopterMember 		[3]
[1] Includes two light-twin helicopters and one medium helicopter that were previously leased-in.
[2] Includes three light-single helicopters and one medium helicopter that were previously leased-in.
[3] Excludes two light-twin helicopters that were removed from service and includes one light-single helicopter that had previously been removed from service.