Significant Accounting Policies (Policies)	3 Months Ended
Significant Accounting Policies (Policies)	Jun. 30, 2018
Accounting Policies [Abstract]
Basis Of Presentation and Consolidation [Policy Text Block]	Basis of Presentation and Consolidation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with the instructions to Form 10 -Q and, therefore, do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for complete financial statements. In the opinion of management, the accompanying Condensed Consolidated Financial Statements contain all adjustments, consisting of normal recurring accruals, necessary to present fairly the financial position of the Company at June 30, 2018, the Statements of Comprehensive Income for the three months ended June 30, 2018 and 2017, and Cash Flows for the three months ended June 30, 2018 and 2017. The results of operations for the three months ended June 30, 2018 are not necessarily indicative of the operating results expected for the fiscal year ending March 31, 2019. These financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s annual report on Form 10 -K for the fiscal year ended March 31, 2018. The Condensed Consolidated Financial Statements include the accounts of PetMed Express, Inc. and its wholly owned subsidiaries. All significant intercompany transactions have been eliminated upon consolidation.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of Condensed Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Condensed Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments The carrying amounts of the Company's cash and cash equivalents, accounts receivable, and accounts payable approximate fair value due to the short-term nature of these instruments.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014 - 09, “Revenue from Contracts with Customers” (“ASC 606” ). ASC 606 clarifies the accounting for revenue arising from contracts with customers and specifies the disclosures that an entity should include in its financial statements. During 2016, the FASB issued certain amendments to the standard relating to the principal versus agent guidance, accounting for licenses of intellectual property and identifying performance obligations as well as the guidance on transition, collectability, noncash consideration and the presentation of sales and other similar taxes. The Company adopted ASC 606 using the modified retrospective method on April 1, 2018. Therefore, the comparative financial information has not been restated and continues to be reported under the accounting standards in effect for those periods. The Company evaluated only contracts not completed at the date of initial application for each of the five steps in ASC 606, which are as follows: 1 ) Identify the contract with the customer; 2 ) Identify the performance obligations in the contract; 3 ) Determine the transaction price; 4 ) Allocate the transaction price to the performance obligations; and 5 ) Recognize revenue when (or as) performance obligations are satisfied. The effect of initially applying ASC 606 did not result in an opening balance adjustment to retained earnings or any other Balance Sheet accounts because the Company: ( 1 ) identified similar performance obligations under ASC 606 as compared with deliverables and separate units of account previously identified; ( 2 ) determined the transaction price to be consistent; and ( 3 ) concluded that revenue is recorded at the same point in time, upon shipment under both ASC 605 and ASC 606. Additionally, the Company concluded that the accounting for fulfillment costs or costs incurred to obtain a contract is unchanged by the adoption of ASC 606. The adoption of ASC 606 did not require significant changes in our internal controls and procedures over financial reporting and disclosures. However, we made enhancements to existing internal controls and procedures to ensure compliance with the new guidance. In February 2016, the FASB issued guidance on leases which supersedes the current lease guidance. The core principle requires lessees to recognize the assets and liabilities that arise from nearly all leases in the statement of financial position. Accounting applied by lessors will remain largely consistent with previous guidance. Additional changes are expected to align lessor accounting with the revised lessee model and the FASB’s revenue recognition guidance. The amendments are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company is currently assessing the impact of this standard on its consolidated financial statements. We do not expect the standard to have a material impact on our consolidated financial statements. The Company does not believe that any other recently issued, but not yet effective, accounting standards, if currently adopted, will have a material effect on the Company’s consolidated financial position, results of operations, or cash flows.