Quarterly report pursuant to Section 13 or 15(d)

Derivative liability for Monte Carlo Simulations (Detail)

v2.4.1.9
Derivative liability for Monte Carlo Simulations (Detail) (Derivative Liability, USD $)
0 Months Ended 1 Months Ended
Mar. 15, 2015
Mar. 31, 2015
Derivative Liability
   
Derivative [Line Items]    
Stated interest rate 8.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
8.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
Exercise price per share $ 0.20us-gaap_FairValueAssumptionsExercisePrice
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
$ 0.20us-gaap_FairValueAssumptionsExercisePrice
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
Expected volatility 90.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
90.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
Risk-free interest rate 0.24%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
0.25%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
Credit adjusted discount rate 20.00%us-gaap_FairValueAssumptionsExpectedDividendRate
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
20.00%us-gaap_FairValueAssumptionsExpectedDividendRate
/ us-gaap_DebtInstrumentAxis
= arth_DerivativeLiabilityMember
Remaining expected term of underlying securities (years) 1 year 11 months 16 days