DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Business Square, Inc. (together with its subsidiaries, Square or the Company) creates tools that empower businesses, sellers and individuals to participate in the economy. Square enables sellers to accept card payments and also provides reporting and analytics, and next-day settlement. Square’s point-of-sale software and other business services help sellers manage inventory, locations, and employees; access financing; engage buyers; build a website or online store; and grow sales. Cash App is an easy way for people to store, send, receive, spend, and invest money. Square was founded in 2009 and is headquartered in San Francisco, with offices in the United States, Canada, Japan, Australia, Ireland, the United Kingdom, Spain, and Lithuania. On March 1, 2021, the industrial loan company charter for Square Financial Services ("SFS"), a wholly owned subsidiary of the Company, was approved by the Federal Deposit Insurance Corporation ("FDIC") and the State of Utah to begin its banking operations. As of March 31, 2021, the operations of SFS have not been material. Basis of Presentation The accompanying interim condensed consolidated financial statements of the Company are unaudited. These interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) and the applicable rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The December 31, 2020 condensed consolidated balance sheet was derived from the audited financial statements as of that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The accompanying unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company's consolidated financial position, results of operations, comprehensive income (loss), and cash flows for the interim periods. All intercompany transactions and balances have been eliminated in consolidation. The interim results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021, or for any other future annual or interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Consolidated Financial Statements and related notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2020. Use of Estimates The preparation of the Company’s condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, as well as related disclosure of contingent assets and liabilities. Actual results could differ from the Company’s estimates. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be materially affected. The Company bases its estimates on current and past experience, to the extent that historical experience is predictive of future performance and other assumptions that the Company believes are reasonable under the circumstances. The Company evaluates these estimates on an ongoing basis. Estimates, judgments, and assumptions in these condensed consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, contingencies, valuation of the debt component of convertible senior notes, valuation of loans held for sale including loans under the Paycheck Protection Program ("PPP"), valuation of goodwill and acquired intangible assets, deferred revenue, determination of income and other taxes, operating and financing lease right-of-use assets and related liabilities, assessing the likelihood of adverse outcomes from claims and disputes, and share-based compensation. In March 2020, the World Health Organization declared the COVID-19 outbreak a global pandemic. The Company operates in geographic locations that have been impacted by COVID-19 and that are subject to various mandated local, state and federally issued public health ordinances, which have impacted the business operations and financial performance of the Company, its employees, and its customers. The extent to which the pandemic will further impact the Company and its customers will depend on future developments, including, but not limited to, various uncertainties that could negatively impact the Company's customers ability to repay outstanding amounts or even continue in business, the duration and ultimate scope of the pandemic, the impact of variants of the disease, the availability and efficacy of vaccines, the speed at which such vaccines are administered, the likelihood of a resurgence of positive cases, further government stimulus assistance programs, and the impact on regional and worldwide economies and financial markets in general, all of which are uncertain and cannot be predicted. The Company continues to revise and update the carrying values of its assets or liabilities based on estimates, judgments and circumstances it is aware of, particularly, the expected impact of COVID-19. The Company's estimates of accrued transaction losses and valuation of loans held for sale are based on historical experience, adjusted for market data relevant to the current economic environment. Specifically related to the COVID-19 pandemic, the Company considers market data for similar historical periods of unprecedented economic conditions and uncertainty in developing such estimates and assumptions. While the COVID-19 pandemic continues to have ongoing global effects, as of March 31, 2021, there have been no material impacts on our estimates, but facts and circumstances could change and impact our estimates and affect our results of operations in future periods. The Company will update its estimates as developments occur and additional information is obtained. The Company will continue to refine its estimates for transaction and loan losses based on actual realized results. Actual results could differ from the estimates, and such differences may be material to the Company's financial statements. See Note 9, Other Consolidated Balance Sheet Components (Current), for further details on transaction losses and Note 5, Fair Value of Financial Instruments, for further details on amortized cost over fair value of the loans. Concentration of Credit Risk For the three months ended March 31, 2021 and March 31, 2020, the Company had no customer that accounted for greater than 10% of total net revenue. The Company had two third-party payment processors that represented approximately 53% and 33% of settlements receivable as of March 31, 2021. As of December 31, 2020, there were two parties that represented approximately 59% and 27% of settlements receivable. All other third-party processors were insignificant. Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, marketable debt securities, settlements receivable, customer funds, reverse repurchase agreements, and loans held for sale. The associated risk of concentration for cash and cash equivalents and restricted cash is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed federal deposit insurance limits. The associated risk of concentration for marketable debt securities is mitigated by holding a diversified portfolio of highly rated investments. Settlements receivable are amounts due from well-established payment processing companies and normally take one or two business days to settle which mitigates the associated risk of concentration. The associated risk with reverse repurchase agreements is mitigated by the securities held as collateral and their short-term nature. The associated risk of concentration for loans held for sale is partially mitigated by credit evaluations that are performed prior to facilitating the offering of loans and ongoing performance monitoring of the Company’s loan customers. The risk associated with the PPP loans is considered low due to government guarantees on those loans. Sales and Marketing Expenses Advertising costs are expensed as incurred and included in sales and marketing expense in the condensed consolidated statements of operations. Total advertising costs for the three months ended March 31, 2021 and 2020, were $85.9 million and $36.2 million. respectively. In addition, services, incentives, and other costs to customers that are not directly related to a revenue generating transaction are recorded as sales and marketing expenses, as the Company considers these to be marketing costs to encourage the usage of Cash App. These expenses, which include, but are not limited to, Cash App peer-to-peer processing costs and related transaction losses, card issuance costs, customer referral bonuses, and promotional giveaways, were $183.6 million and $106.8 million, for the three months ended March 31, 2021 and 2020, respectively. Recently Adopted Accounting Pronouncements In August 2020, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2020-06, Accounting for Convertible Instruments and Contracts in an Entity's Own Equity, as part of its overall simplification initiative to reduce costs and complexity of applying accounting standards while maintaining or improving the usefulness of the information provided to users of financial statements. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2021, and interim periods within those fiscal years, with early adoption permitted, but only at the beginning of the fiscal year. The Company early adopted the new guidance on January 1, 2021 using the modified retrospective approach and recorded a cumulative effect upon adoption of $103.0 million as a reduction to accumulated deficit and a reduction to other paid in capital of $502.7 million related to amounts attributable to conversion options that had previously been recorded in equity. Additionally, the Company recorded an increase to its convertible notes balance by an aggregate amount of $399.7 million as a result of the reversal of the separation of the convertible debt between debt and equity. The adoption of this standard also significantly decreased the amount of non-cash interest expense to be recognized in future periods as a result of eliminating the discount associated with the equity component. There was no impact to the Company’s statements of cash flows as the result of the adoption of ASU No. 2020-06. In October 2020, the FASB issued ASU No. 2020-10, Codification Improvements ("Codification"). The update provides incremental improvements on various topics in the Codification to provide clarification, correct errors in, and to provide simplification on a variety of topics. Among other items, the guidance includes presentation disclosures for the amount of income tax expense or benefit related to other comprehensive income. The amendments are effective for public entities in fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Early adoption is permitted. The Company adopted this guidance effective January 1, 2021 and has applied the guidance prospectively. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures.