Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Claim Against ICAR On June 11, 2018, a claim was filed before the Juzgado de Primera Instancia number 5 of Barcelona, Spain, the first instance court in the Spanish civil procedure system, against ICAR. The claim, also directed to Mr. Xavier Codó Grasa, former controlling shareholder of ICAR and its current General Manager, was brought by the Spanish company Global Equity & Corporate Consulting, S.L. for the alleged breach by ICAR of a services agreement entered into in the context of the ICAR Acquisition. ICAR responded to the claim on September 7, 2018 and the court process is ongoing. The amount claimed is €0.8 million (or $0.9 million), plus the interests accrued during the court proceedings. Pursuant and subject to the terms of the sale and purchase agreement concerning the acquisition of the shares in ICAR, Mitek Holding B.V. is to be indemnified in respect of any damages suffered by ICAR and/or Mitek Holding B.V. in respect of this claim. Other Legal Matters In addition to the foregoing, the Company is subject to various claims and legal proceedings arising in the ordinary course of its business. The Company accrues for such liabilities when it is both (i) probable that a loss has occurred and (ii) the amount of the loss can be reasonably estimated in accordance with ASC 450. While any legal proceeding has an element of uncertainty, the Company believes that the disposition of such matters, in the aggregate, will not have a material effect on the Company’s financial condition or results of operations. Facility Leases The Company’s principal executive offices, as well as its research and development facility, are located in approximately 29,000 square feet of office space in San Diego, California and the term of the lease for the Company’s offices continues through June 30, 2024. The average annual base rent under this lease is approximately $1.0 million per year. In connection with this lease, the Company received tenant improvement allowances totaling $1.0 million. These lease incentives are being amortized as a reduction of rent expense over the term of the lease. As of December 31, 2018, the unamortized balance of the lease incentives was $0.8 million, of which $0.1 million has been included in other current liabilities and $0.6 million has been included in other non-current liabilities. The offices of A2iA are located in France and New York, New York and the terms of each lease continue through July 31, 2021 and September 30, 2019, respectively, with annual base rent of approximately €0.4 million (or approximately $0.4 million) and approximately $0.3 million per year, respectively. The offices of IDchecker are located in the Netherlands and the term of such lease continues through December 31, 2023 with annual base rent of approximately €0.2 million (or approximately $0.2 million) per year. The Company has a sales office in London, UK. The term of this lease continues through May 31, 2020. The annual base rent under this lease is approximately £63,000 (or approximately $80,000) per year. The offices of ICAR are located in Barcelona, Spain and the term of such lease continues through May 31, 2023 with annual base rent of approximately €0.1 million (or approximately $0.1 million) per year. The Company believes its existing properties are in good condition and are sufficient and suitable for the conduct of its business. Revolving Credit Facility On May 3, 2018, the Company and IDChecker, Inc. (together, the “Co-Borrowers”) entered into a Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (“SVB”). Pursuant to the Loan Agreement, the Company arranged for a $10.0 million secured revolving credit facility (the “Revolver”) with a floating per annum interest rate equal to the greater of the Wall Street Journal prime rate, plus 0.25%, or 4.5%. The Co-Borrowers must maintain, at all times when any amounts are outstanding under the Revolver, either (i) minimum unrestricted cash at SVB and unused availability on the Revolver of at least $15.0 million and (ii) Adjusted Quick Ratio of 1.75:1.00. The Revolver has a maturity date of May 3, 2019. There were no borrowings outstanding under the Revolver as of December 31, 2018.