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Stock Based Compensation (Details) (USD $)
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3 Months Ended | 12 Months Ended |
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Mar. 31, 2015
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Dec. 31, 2014
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Number of Options, Outstanding | 1,607,075us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber | |
| Number of Options, Granted | 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross | |
| Number of Options, Exercised | 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised | |
| Number of Options, Forfeited | 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod | |
| Number of Options, Outstanding | 1,607,075us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber | 1,607,075us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber |
| Number of Options, Exercisable | 550,298us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber | |
| Number of Options, Vested | 103,787watt_ShareBasedCompensationArrangementShareBasedPaymentAwardOptionsVestedInPeriodShares | |
| Number of Options, Exercisable | 654,085us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber | 550,298us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber |
| Weighted Average Exercise Price, Outstanding | $ 4.41us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice | |
| Weighted Average Exercise Price, Granted | $ 0us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice | |
| Weighted Average Exercise Price, Exercised | $ 0us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice | |
| Weighted Average Exercise Price, Forfeited | $ 0us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice | |
| Weighted Average Exercise Price, Outstanding | $ 4.41us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice | $ 4.41us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice |
| Weighted Average Exercise Price, Exercisable | $ 4.33us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice | |
| Weighted Average Exercise Price, Vested | $ 4.61watt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedInPeriodWeightedAverageExercisePrice | |
| Weighted Average Exercise Price, Exercisable | $ 4.37us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice | $ 4.33us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice |
| Weighted Average Grant Date Fair Value, Outstanding | $ 2.47us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue | |
| Weighted Average Grant Date Fair Value, Granted | $ 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue | |
| Weighted Average Grant Date Fair Value, Exercised | $ 0watt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageGrantDateFairValue | |
| Weighted Average Grant Date Fair Value, Forfeited | $ 0us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue | |
| Weighted Average Grant Date Fair Value, Outstanding | $ 2.47us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue | $ 2.47us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue |
| Weighted Average Grant Date Fair Value, Exercisable | $ 2.41watt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableGrantDateFairValue | |
| Weighted Average Grant Date Fair Value, Vested | $ 0us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue | |
| Weighted Average Grant Date Fair Value, Exercisable | $ 2.44watt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableGrantDateFairValue | $ 2.41watt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableGrantDateFairValue |
| Weighted Average Remaining Life In Years, Outstanding | 8 years 10 months 24 days | 9 years |
| Weighted Average Remaining Life In Years, Exercisable | 8 years 10 months 24 days | 9 years 1 month 6 days |
| Intrinsic Value, Outstanding | $ 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue | |
| Intrinsic Value, Exercised | ||
| Intrinsic Value, Outstanding | 8,089,568us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue | 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue |
| Intrinsic Value, Exercisable | 0us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 | |
| Intrinsic Value, Exercisable | $ 3,314,780us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 | $ 0us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 |
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- Details
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- Definition
Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Gross number of share options (or share units) granted during the period. No definition available.
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- Definition
The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average grant-date fair value of non-vested options forfeited. No definition available.
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- Definition
Weighted average grant-date fair value of non-vested options outstanding. No definition available.
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- Definition
Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of options outstanding, including both vested and non-vested options. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average grant-date fair value of options vested. No definition available.
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- Definition
Weighted average price at which option holders acquired shares when converting their stock options into shares. No definition available.
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- Definition
Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated. No definition available.
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- Definition
Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. No definition available.
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- Definition
Number of share options (or share units) exercised during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average grant-date fair value of options exercisable as of the balance sheet date No definition available.
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- Definition
The weighted average grant-date fair value of options exercised during the reporting period as calculated by applying the disclosed option pricing methodology. No definition available.
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- Definition
The weighted-average price of stock options vested in period. No definition available.
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- Definition
Number of options vested during the period which excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. No definition available.
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