Annual report pursuant to Section 13 and 15(d)

STOCK-BASED COMPENSATION (Details)

v2.4.1.9
STOCK-BASED COMPENSATION (Details) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Jun. 03, 2014
Stock-based compensation      
Granted (in shares) 491,200us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross  
Vested (in shares) (142,895)us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares    
Aggregate grant date fair value at end of the reporting period (in dollars) $ 4.14resn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageGrantDateFairValue    
Fair values of stock options granted, as estimated using Black-Scholes option valuation model assumptions:      
Stock Price (in dollars per share)   $ 5.54us-gaap_SharePrice $ 6.00us-gaap_SharePrice
Common stock options      
Stock-based compensation      
Aggregate grant date fair value of options granted $ 2.0resn_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantedInPeriodFairValue1
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
   
Granted (in shares) 491,200us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
   
Number of quarters from the date of grant subsequent to initial vesting, over which the awards vest 16resn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfQuartersOverWhichAwardsVestFromGrantDateSubsequentToInitialVesting
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
   
Common stock options | Minimum      
Stock-based compensation      
Exercise price range, lower limit (in dollars per share) $ 5.79us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
   
Term of award 3 years    
Fair values of stock options granted, as estimated using Black-Scholes option valuation model assumptions:      
Stock Price (in dollars per share) $ 5.79us-gaap_SharePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
   
Expected Volatility (as a percent) 56.60%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
   
Risk-free interest rate (as a percent) 1.52%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
   
Expected Life 4 years    
Common stock options | Maximum      
Stock-based compensation      
Exercise price range, upper limit (in dollars per share) $ 8.06us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Term of award 10 years    
Fair values of stock options granted, as estimated using Black-Scholes option valuation model assumptions:      
Stock Price (in dollars per share) $ 8.06us-gaap_SharePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Dividend Yield (as a percent) 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Expected Volatility (as a percent) 82.20%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Risk-free interest rate (as a percent) 2.56%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Expected Life 7 years    
Restricted stock units      
Stock-based compensation      
Granted (in shares) 174,500us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
   
2014 Omnibus Incentive Plan      
Stock-based compensation      
Number of shares of common stock approved for issuance 1,400,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= resn_OmnibusIncentivePlan2014Member