Annual report pursuant to Section 13 and 15(d)

VARIABLE INTEREST ENTITIES AND EQUITY INVESTMENTS AND ADVANCES Schedule of Equity Method Investment, Financial Information, Balance Sheets (Details)

v2.4.1.9
VARIABLE INTEREST ENTITIES AND EQUITY INVESTMENTS AND ADVANCES Schedule of Equity Method Investment, Financial Information, Balance Sheets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dart Helicopter Services LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Current assets $ 22,447us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
$ 19,231us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
Non-current assets 34,309us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
37,636us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
Current liabilities 4,386us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
8,613us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
Non-current liabilities 8,907us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
6,963us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= era_DartHelicopterServicesLLCMember
Other Investments [Member]    
Schedule of Equity Method Investments [Line Items]    
Current assets 1,151us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
4,378us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
Non-current assets 5,899us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
20,018us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
Current liabilities 465us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
2,789us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
Non-current liabilities $ 4,298us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember
$ 7,918us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= us-gaap_OtherInvestmentsMember