Quarterly report pursuant to Section 13 or 15(d)

NOTE PAYABLE - Additional Information (Detail)

v2.4.1.9
NOTE PAYABLE - Additional Information (Detail) (USD $)
3 Months Ended 6 Months Ended 1 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2015
Mar. 31, 2014
Sep. 30, 2013
Sep. 30, 2014
Note Payable [Line Items]            
Interest Expense, Debt $ 2,764us-gaap_InterestExpenseDebt $ 5,529us-gaap_InterestExpenseDebt $ 2,764us-gaap_InterestExpenseDebt $ 5,529us-gaap_InterestExpenseDebt    
Debt instrument, unamortized discount 961,295us-gaap_DebtInstrumentUnamortizedDiscount   961,295us-gaap_DebtInstrumentUnamortizedDiscount     955,766us-gaap_DebtInstrumentUnamortizedDiscount
Loans            
Note Payable [Line Items]            
Notes Payable, Total 944,707us-gaap_NotesPayable
/ us-gaap_AssetsSoldUnderAgreementsToRepurchaseAxis
= us-gaap_LoansMember
  944,707us-gaap_NotesPayable
/ us-gaap_AssetsSoldUnderAgreementsToRepurchaseAxis
= us-gaap_LoansMember
     
Warrant            
Note Payable [Line Items]            
Adjustments to Additional Paid in Capital, Warrant Issued     55,293us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_WarrantMember
     
Fair Value Assumptions, Risk Free Interest Rate     2.64%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_WarrantMember
     
Fair Value Assumptions, Expected Dividend Rate     0.00%us-gaap_FairValueAssumptionsExpectedDividendRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_WarrantMember
     
Fair Value Assumptions, Expected Term     10 years      
Fair Value Assumptions, Expected Volatility Rate     114.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_WarrantMember
     
Massachusetts Life Sciences Center            
Note Payable [Line Items]            
Subordinated Debt         $ 1,000,000us-gaap_SubordinatedDebt
/ dei_LegalEntityAxis
= arth_MassachusettsLifeSciencesCenterMember
 
Debt Instrument, Payment Terms         The loan bears interest at a rate of 10% per annum, and will become fully due and payable on the earlier of (i) September 30, 2018, (ii) the occurrence of an event of default under the MLSC Loan Agreement, or (iii) the completion of a sale of substantially all of our assets, a change-of-control transaction or one or more financing transactions in which we receive net proceeds of $5,000,000 or more in a 12-month period.  
Warrants Issued To Purchase Of Common Stock         145,985arth_WarrantsIssuedToPurchaseOfCommonStock
/ dei_LegalEntityAxis
= arth_MassachusettsLifeSciencesCenterMember
 
Class Of Warrant Or Right Expiration Date         Sep. 30, 2023  
Class of Warrant or Right, Exercise Price of Warrants or Rights         $ 0.27us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ dei_LegalEntityAxis
= arth_MassachusettsLifeSciencesCenterMember