Quarterly report pursuant to Section 13 or 15(d)

EARNINGS (LOSS) PER COMMON SHARE (Details)

v2.4.1.9
EARNINGS (LOSS) PER COMMON SHARE (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Net income attributable to common shares $ (42)era_NetIncomeLossAvailabletoVestedCommonStockholdersBasic [1] $ 4,389era_NetIncomeLossAvailabletoVestedCommonStockholdersBasic [1]
Weighted average number of common shares outstanding—basic (in shares) 20,195,955us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 19,952,930us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Weighted average number of common shares outstanding—diluted (in shares) 20,195,955us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 20,025,135us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Basic Earnings per Common Share (in dollars per share) $ 0.00us-gaap_EarningsPerShareBasic $ 0.22us-gaap_EarningsPerShareBasic
Diluted Earnings per Common Share (in dollars per share) $ 0.00us-gaap_EarningsPerShareDiluted $ 0.22us-gaap_EarningsPerShareDiluted
Restricted Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Net income attributable to common shares $ 0era_NetIncomeLossAvailabletoUnvestedCommonStockholdersBasic
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_RestrictedStockMember
$ 56era_NetIncomeLossAvailabletoUnvestedCommonStockholdersBasic
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_RestrictedStockMember
Stock Options and Restricted Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Net effect of dilutive stock options and restricted stock awards based on the treasury stock method (in shares) 0us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= era_StockOptionsAndRestrictedStockMember
[2] 72,205us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= era_StockOptionsAndRestrictedStockMember
[2]
Unvested restricted common shares 114,955us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= era_StockOptionsAndRestrictedStockMember
6,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= era_StockOptionsAndRestrictedStockMember
[1] Excludes net income of $0 and $56 attributable to unvested common shares for the three months ended March 31, 2015 and 2014, respectively.
[2] Excludes weighted average common shares of 114,955 and 6,000 for the three months ended March 31, 2015 and 2014, respectively, for certain share awards as the effect of their inclusion would have been antidilutive.