Stockholders' Equity (Deficit) (Details Textual) (USD $)
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1 Months Ended |
12 Months Ended |
1 Months Ended |
0 Months Ended |
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Apr. 30, 2014
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Dec. 31, 2014
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Dec. 31, 2013
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Mar. 31, 2014
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Dec. 15, 2014
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Mar. 26, 2014
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Mar. 07, 2014
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Apr. 02, 2014
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Class of Stock [Line Items] |
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Common Stock, Shares Authorized |
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50,000,000us-gaap_CommonStockSharesAuthorized
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40,000,000us-gaap_CommonStockSharesAuthorized
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60,000,000us-gaap_CommonStockSharesAuthorized
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Preferred Stock, Shares Authorized |
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10,000,000us-gaap_PreferredStockSharesAuthorized
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0us-gaap_PreferredStockSharesAuthorized
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10,000,000us-gaap_PreferredStockSharesAuthorized
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Proceeds from Issuance Initial Public Offering |
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$ 24,872,170us-gaap_ProceedsFromIssuanceInitialPublicOffering
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$ 0us-gaap_ProceedsFromIssuanceInitialPublicOffering
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Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount |
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3,261,360us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
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3,525,904us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
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Sale of Stock, Price Per Share |
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$ 0.0001us-gaap_SaleOfStockPricePerShare
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Proceeds from Other Equity |
700,000us-gaap_ProceedsFromOtherEquity
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900,000us-gaap_ProceedsFromOtherEquity
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0us-gaap_ProceedsFromOtherEquity
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Payments for Commissions |
100,000us-gaap_PaymentsForCommissions
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100,000us-gaap_PaymentsForCommissions
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Payments of Stock Issuance Costs |
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2,816,149us-gaap_PaymentsOfStockIssuanceCosts
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Common Stock [Member] |
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Class of Stock [Line Items] |
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Stock Issued During Period, Shares, New Issues |
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4,600,000us-gaap_StockIssuedDuringPeriodSharesNewIssues / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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Proceeds from Issuance or Sale of Equity |
1,000,000us-gaap_ProceedsFromIssuanceOrSaleOfEquity / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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1,000,000us-gaap_ProceedsFromIssuanceOrSaleOfEquity / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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Stock Issued During Period, Shares, Issued for Services |
210,527us-gaap_StockIssuedDuringPeriodSharesIssuedForServices / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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210,527us-gaap_StockIssuedDuringPeriodSharesIssuedForServices / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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210,527us-gaap_StockIssuedDuringPeriodSharesIssuedForServices / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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Proceeds from Other Equity |
700,000us-gaap_ProceedsFromOtherEquity / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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300,000us-gaap_ProceedsFromOtherEquity / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
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IPO [Member] |
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Class of Stock [Line Items] |
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Stock Issued During Period, Shares, New Issues |
4,600,000us-gaap_StockIssuedDuringPeriodSharesNewIssues / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Shares Issued, Price Per Share |
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$ 6.00us-gaap_SharesIssuedPricePerShare / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Proceeds from Issuance or Sale of Equity |
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25,214,596us-gaap_ProceedsFromIssuanceOrSaleOfEquity / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Payments for Underwriting Expense |
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177,404us-gaap_PaymentsForUnderwritingExpense / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Proceeds from Issuance Initial Public Offering |
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24,783,851us-gaap_ProceedsFromIssuanceInitialPublicOffering / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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20,993,759us-gaap_ProceedsFromIssuanceInitialPublicOffering / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Common Stock, Discount on Shares |
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2,208,000us-gaap_CommonStockDiscountOnShares / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Payments of Stock Issuance Costs |
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430,745us-gaap_PaymentsOfStockIssuanceCosts / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_IPOMember
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Over-Allotment Option [Member] |
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Class of Stock [Line Items] |
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Stock Issued During Period, Shares, New Issues |
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600,000us-gaap_StockIssuedDuringPeriodSharesNewIssues / us-gaap_SubsidiarySaleOfStockAxis = us-gaap_OverAllotmentOptionMember
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Secondary Offering [Member] |
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Class of Stock [Line Items] |
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Sale of Stock, Price Per Share |
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$ 7.00us-gaap_SaleOfStockPricePerShare / us-gaap_SubsidiarySaleOfStockAxis = watt_SecondaryOfferingMember
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Payments of Stock Issuance Costs |
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246,239us-gaap_PaymentsOfStockIssuanceCosts / us-gaap_SubsidiarySaleOfStockAxis = watt_SecondaryOfferingMember
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Stock Issued During Period, Value, Other |
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3,285,714us-gaap_StockIssuedDuringPeriodValueOther / us-gaap_SubsidiarySaleOfStockAxis = watt_SecondaryOfferingMember
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Secondary Offering [Member] | Underwriter [Member] |
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Class of Stock [Line Items] |
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Proceeds from Issuance or Sale of Equity |
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21,239,998us-gaap_ProceedsFromIssuanceOrSaleOfEquity / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = watt_UnderwriterMember / us-gaap_SubsidiarySaleOfStockAxis = watt_SecondaryOfferingMember
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Payments for Underwriting Expense |
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150,000us-gaap_PaymentsForUnderwritingExpense / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = watt_UnderwriterMember / us-gaap_SubsidiarySaleOfStockAxis = watt_SecondaryOfferingMember
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Common Stock, Discount on Shares |
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$ 1,610,000us-gaap_CommonStockDiscountOnShares / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = watt_UnderwriterMember / us-gaap_SubsidiarySaleOfStockAxis = watt_SecondaryOfferingMember
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Initial Public Offering Warrant [Member] |
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Class of Stock [Line Items] |
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Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount |
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460,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount / us-gaap_StatementClassOfStockAxis = watt_InitialPublicOfferingWarrantMember
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Investment Warrants, Exercise Price |
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$ 7.50invest_InvestmentWarrantsExercisePrice / us-gaap_StatementClassOfStockAxis = watt_InitialPublicOfferingWarrantMember
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