Post-effective amendment to a registration statement that is not immediately effective upon filing

Related Party Transactions - Additional Information (Detail)

v2.4.1.9
Related Party Transactions - Additional Information (Detail) (USD $)
0 Months Ended 1 Months Ended 12 Months Ended 25 Months Ended 31 Months Ended 83 Months Ended 91 Months Ended 1 Months Ended
Jun. 05, 2011
Nov. 30, 2010
Sep. 30, 2014
Sep. 30, 2013
Feb. 28, 2011
Dec. 31, 2008
Jan. 31, 2013
Sep. 30, 2013
Feb. 28, 2009
Apr. 20, 2013
Mar. 31, 2013
Oct. 31, 2012
Sep. 30, 2012
Related Party Transaction [Line Items]                          
Proceeds from convertible debt $ 250,000us-gaap_ProceedsFromConvertibleDebt   $ 0us-gaap_ProceedsFromConvertibleDebt $ 250,000us-gaap_ProceedsFromConvertibleDebt $ 275,200us-gaap_ProceedsFromConvertibleDebt $ 105,000us-gaap_ProceedsFromConvertibleDebt $ 1,735,000us-gaap_ProceedsFromConvertibleDebt            
Convertible preferred stock, value, upon closing of preferred equity financing 750,000arth_ConvertiblePreferredStockValueUponClosingOfPreferredEquityFinancing   1,000,000arth_ConvertiblePreferredStockValueUponClosingOfPreferredEquityFinancing                    
Percentage of principle balance of notes on conversion price of notes     20.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes                    
Percentage of conversion price of convertible preferred stock     20.00%arth_PercentageOfConversionPriceOfConvertiblePreferredStock                    
Current maturities of convertible notes payable, related parties             105,000arth_ConvertibleNotesPayableRelatedPartiesCurrent       1,345,000arth_ConvertibleNotesPayableRelatedPartiesCurrent    
Convertible notes, total aggregate principal balance                   1,880,000us-gaap_DebtInstrumentCarryingAmount      
Cash bonus   500,000arth_CashBonus                      
Debt instrument, convertible, threshold amount   1,000,000arth_DebtInstrumentConvertibleThresholdAmount                      
Convertible preferred stock value upon closing   100,000arth_ConvertiblePreferredStockValueUponClosing                      
Matured Convertible Notes                       50,000arth_MaturedConvertibleNotes 1,245,000arth_MaturedConvertibleNotes
Related Parties                          
Related Party Transaction [Line Items]                          
Convertible notes, total aggregate principal balance                   1,880,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= arth_RelatedPartiesMember
     
Matured Convertible Notes             $ 50,000arth_MaturedConvertibleNotes
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= arth_RelatedPartiesMember
          $ 55,000arth_MaturedConvertibleNotes
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= arth_RelatedPartiesMember
Maximum                          
Related Party Transaction [Line Items]                          
Percentage of principle balance of notes on conversion price of notes     10.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
      50.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
50.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
         
Minimum                          
Related Party Transaction [Line Items]                          
Percentage of principle balance of notes on conversion price of notes     6.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
10.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
    10.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
10.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
         
Accrued Interest Through December Thirty One Two Thousand And Nine                          
Related Party Transaction [Line Items]                          
Percentage of principle balance of notes on conversion price of notes                 6.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_DebtInstrumentAxis
= arth_AccruedInterestThroughDecemberThirtyOneTwoThousandAndNineMember
       
Accrued Interest Beginning January One Two Thousand And Ten                          
Related Party Transaction [Line Items]                          
Percentage of principle balance of notes on conversion price of notes                 10.00%arth_PercentageOfPrincipleBalanceOfNotesOnConversionPriceOfNotes
/ us-gaap_DebtInstrumentAxis
= arth_CcruedInterestBeginningJanuaryOneTwoThousandAndTenMember