Annual report pursuant to Section 13 and 15(d)

SHARE-BASED COMPENSATION Narrative (Details)

v2.4.1.9
SHARE-BASED COMPENSATION Narrative (Details) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation expense $ 5.8us-gaap_AllocatedShareBasedCompensationExpense $ 2.0us-gaap_AllocatedShareBasedCompensationExpense
Unrecognized compensation costs 4.2us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized  
Fair value of stock options granted $ 10.86us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue $ 9.59us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Aggregate intrinsic value of exercised stock options 0.2us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 0.4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Weighted average remaining contractual term for total outstanding stock options and vested/exercisable stock options 4 years 5 months 23 days 3 years 3 months 15 days
Aggregate intrinsic value of all options outstanding and all vested/exercisable options outstanding 0.7us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue  
Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted (in shares) 127,050us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
270,360us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Granted $ 29.23us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
$ 21.28us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Fair value of closing price on grant date 4.1us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
0.1us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Accelerated vesting of shares $ 1.6era_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsAcceleratedVestingFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
 
Era Group Inc. 2013 Employee Stock Purchase Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Maximum number of shares authorized   300,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= era_EraGroupInc.2013EmployeeStockPurchasePlanMember
Shares remaining available for grant 246,914us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= era_EraGroupInc.2013EmployeeStockPurchasePlanMember
300,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= era_EraGroupInc.2013EmployeeStockPurchasePlanMember
Percentage of stock price employees can purchase   85.00%era_SharebasedCompensationArrangementbySharebasedPaymentAwardEmployeeSockPricePercentage
/ us-gaap_PlanNameAxis
= era_EraGroupInc.2013EmployeeStockPurchasePlanMember
Offering period   6 months
Expiration period   10 years
Common Stock [Member] | Era Group Inc. 2012 Incentive Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Maximum number of shares authorized   4,000,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= era_EraGroupInc2012IncentivePlanMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember
Shares remaining available for grant 3,216,798us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= era_EraGroupInc2012IncentivePlanMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember
3,364,998us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= era_EraGroupInc2012IncentivePlanMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember