Summary of business and significant accounting policies | HealthEquity, Inc. was incorporated in the state of Delaware on September 18, 2002, and was organized to offer a full range of innovative solutions for managing health care accounts (Health Savings Accounts, Health Reimbursement Arrangements, and Flexible Spending Accounts) for health plans, insurance companies, and third-party administrators. Principles of consolidation —The condensed consolidated financial statements include the accounts of HealthEquity, Inc. and its wholly owned subsidiaries, HEQ Insurance Services, Inc., and HealthEquity Advisors, LLC (collectively referred to as the "Company"). During the year ended January 31, 2015, the Company and an unrelated company formed a limited partnership for investment in and the management of early stage companies in the healthcare industry. The Company has a 22% ownership interest in such partnership accounted for using the equity method of accounting. The investment was approximately $281,000 as of July 31, 2015 and is included in other assets on the accompanying condensed consolidated balance sheet. All significant intercompany balances and transactions have been eliminated. Basis of presentation —The accompanying condensed consolidated financial statements as of July 31, 2015 and for the three and six months ended July 31, 2015 and 2014 are unaudited and have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP") and the applicable rules and regulations of the Securities and Exchange Commission ("SEC") regarding interim financial reporting. In the opinion of management, the interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the results for the interim periods. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company's Annual Report on Form 10-K for the year ended January 31, 2015. The fiscal year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. Follow-on offering —On May 11, 2015, the Company closed its follow-on public offering and sold 972,500 shares of common stock at a public offering price of $25.90 per share, less the underwriters' discount. Certain selling stockholders sold 3,455,000 shares of common stock in the offering, including 380,000 shares of common stock which were issued upon the exercise of outstanding options. The Company received net proceeds of approximately $23.5 million after deducting underwriting discounts and commissions of approximately $1.0 million and other offering expenses payable by the Company of approximately $688,000 . The Company did not receive any proceeds from the sale of shares by the selling stockholders other than $222,000 representing the exercise price of the options that were exercised in connection with the offering. Marketable securities —Marketable securities consist primarily of mutual funds invested in corporate bonds, U.S. government agency securities, U.S. treasury bills, commercial paper, certificates of deposit, municipal notes, and bonds with original maturities beyond three months at the time of purchase. Marketable securities are classified as available-for-sale, held-to-maturity, or trading at the date of purchase. As of July 31, 2015 , all marketable securities have been classified as available-for-sale. The Company may sell these securities at any time for use in current operations or for other purposes even if they have not yet reached maturity. As a result, the Company classifies its marketable securities, including securities with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. All marketable securities are recorded at their estimated fair value. Unrealized gains and losses for available-for-sale securities are recorded in other comprehensive income. The Company evaluates its marketable securities to assess whether those with unrealized loss positions are other-than-temporarily impaired. The Company considers impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely it will sell the securities before the recovery of their cost basis. Realized gains and losses and declines in value judged to be other-than-temporary are determined based on the specific identification method and are reported in other expense, net in the condensed consolidated statements of operations and comprehensive income. Recent accounting pronouncements —On May 28, 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in GAAP when it becomes effective. In July 2015, the FASB voted to defer the effective date to fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017, with early adoption beginning for fiscal years, and interim periods within those fiscal years, beginning after December 31, 2016. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on the consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor determined the effect of the standard on the ongoing financial reporting. Business combinations —Acquisition-related expenses are recognized in earnings in the period in which they are incurred. During the three and six months ended July 31, 2015, the Company incurred $ 571,000 and $661,000 , respectively, of acquisition-related expenses which is included in other expense, net on the condensed consolidated statement of operations. There were no business combinations during the three and six months ended July 31, 2015. Revision of previously issued financial statements —During the three months ended October 31, 2014, the Company identified an error that originated in the three months ended July 31, 2014 . This error was caused by using an incorrect fair value amount in calculating the windfall tax benefit for a portion of the vested options exercised during the period. The adjustment increased other current assets and additional paid-in capital by approximately $1.0 million . The error also decreased cash provided by operating activities by $1.0 million and increased cash provided by financing activities by the same amount. The error had no impact to the condensed consolidated statement of operations and comprehensive income. The Company determined this error did not materially impact the July 31, 2014 financial statements nor the October 31, 2014 financial statements; however, in order to correctly present the financial statements, the condensed consolidated statement of cash flows for the six months ended July 31, 2014 has been revised to reflect this correction. |