Fair Value Measurements Using Significant Unobservable Inputs Level 3 (Detail) (USD $)
|
2 Months Ended |
3 Months Ended |
Dec. 31, 2014
|
Dec. 31, 2014
|
Dec. 31, 2013
|
Modification of Warrants |
$ 1,300,170arth_GainOnWarrantDerivativeModification
|
$ (1,300,170)arth_GainOnWarrantDerivativeModification
|
$ 0arth_GainOnWarrantDerivativeModification
|
Exercises of Warrants |
224,000arth_GainOnExerciseOfWarrants
|
224,000arth_GainOnExerciseOfWarrants
|
0arth_GainOnExerciseOfWarrants
|
Adjustments to estimated fair value |
|
7,541,693arth_FairValueOfDerivativeLiabilitiesInExcessOfProceeds
|
|
Ending balance at December 31, 2014 |
4,593,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
|
4,593,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
|
|
Fair Value, Inputs, Level 3 |
|
|
|
Beginning balance at September 30, 2014 |
|
6,270,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue / dei_LegalEntityAxis = us-gaap_FairValueInputsLevel3Member
|
|
Modification of Warrants |
|
1,300,170arth_GainOnWarrantDerivativeModification / dei_LegalEntityAxis = us-gaap_FairValueInputsLevel3Member
|
|
Exercises of Warrants |
|
(224,000)arth_GainOnExerciseOfWarrants / dei_LegalEntityAxis = us-gaap_FairValueInputsLevel3Member
|
|
Adjustments to estimated fair value |
|
(2,753,170)arth_FairValueOfDerivativeLiabilitiesInExcessOfProceeds / dei_LegalEntityAxis = us-gaap_FairValueInputsLevel3Member
|
|
Ending balance at December 31, 2014 |
$ 4,593,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue / dei_LegalEntityAxis = us-gaap_FairValueInputsLevel3Member
|
$ 4,593,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue / dei_LegalEntityAxis = us-gaap_FairValueInputsLevel3Member
|
|