Block (XYZ) 10-Q 1 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 27, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Square, Inc.
Entity Central Index Key	1,512,673
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Class A
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		301,612,405
Class B
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		108,815,689

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,387,977	$ 696,474
Short-term investments	233,599	169,576
Restricted cash	27,487	28,805
Settlements receivable	806,688	620,523
Customer funds	208,855	103,042
Loans held for sale	85,040	73,420
Other current assets	120,250	86,454
Total current assets	2,869,896	1,778,294
Property and equipment, net	121,708	91,496
Goodwill	255,656	58,327
Acquired intangible assets, net	85,514	14,334
Long-term investments	168,150	203,667
Restricted cash	12,908	9,802
Other non-current assets	40,995	31,350
Total assets	3,554,827	2,187,270
Current liabilities:
Accounts payable	9,214	16,763
Customers payable	1,001,422	733,736
Settlements payable	140,616	114,788
Accrued transaction losses	29,207	26,893
Accrued expenses	74,816	52,280
Other current liabilities	60,635	28,367
Total current liabilities	1,315,910	972,827
Long-term debt (Note 12)	1,071,437	358,572
Other non-current liabilities	85,851	69,538
Total liabilities	2,473,198	1,400,937
Commitments and contingencies (Note 17)
Stockholders’ equity:
Preferred stock, $0.0000001 par value: 100,000,000 shares authorized at June 30, 2018 and December 31, 2017. None issued and outstanding at June 30, 2018 and December 31, 2017.	0	0
Additional paid-in capital	1,963,298	1,630,386
Accumulated other comprehensive loss	(4,456)	(1,318)
Accumulated deficit	(877,213)	(842,735)
Total stockholders’ equity	1,081,629	786,333
Total liabilities and stockholders’ equity	3,554,827	2,187,270
Class A
Stockholders’ equity:
Common stock	0	0
Class B
Stockholders’ equity:
Common stock	$ 0	$ 0

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Preferred stock, par value (in USD per share)	$ 0.00	$ 0.00
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A
Class of Stock [Line Items]
Common stock, par value (in USD per share)	$ 0.00	$ 0.00
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	297,371,047	280,400,813
Common stock, shares outstanding (in shares)	297,371,047	280,400,813
Class B
Class of Stock [Line Items]
Common stock, par value (in USD per share)	$ 0.00	$ 0.00
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	109,580,981	114,793,262
Common stock, shares outstanding (in shares)	109,580,981	114,793,262

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue:
Revenue	$ 814,938	$ 551,505	$ 1,483,541	$ 1,013,059
Cost of revenue:
Total cost of revenue	499,122	344,076	912,555	632,199
Gross profit	315,816	207,429	570,986	380,860
Operating expenses:
Product development	114,800	78,126	219,895	146,708
Sales and marketing	98,243	59,916	175,509	109,816
General and administrative	82,772	62,988	158,273	119,923
Transaction, loan and advance losses	21,976	18,401	40,007	30,292
Amortization of acquired customer assets	2,816	1,943	4,691	4,064
Total operating expenses	318,463	219,653	594,625	407,166
Operating loss	(2,647)	(12,224)	(23,639)	(26,306)
Interest and other expense, net	2,655	3,266	5,474	3,765
Loss before income tax	(5,302)	(15,490)	(29,113)	(30,071)
Provision for income taxes	604	472	779	981
Net loss	$ (5,906)	$ (15,962)	$ (29,892)	$ (31,052)
Net loss per share:
Basic (in USD per share)	$ (0.01)	$ (0.04)	$ (0.07)	$ (0.08)
Diluted (in USD per share)	$ (0.01)	$ (0.04)	$ (0.07)	$ (0.08)
Weighted-average shares used to compute net loss per share
Basic (in shares)	403,301	376,357	399,624	371,573
Diluted (in shares)	403,301	376,357	399,624	371,573
Transaction-based revenue
Revenue:
Revenue	$ 625,228	$ 482,065	$ 1,148,265	$ 885,543
Cost of revenue:
Cost of revenue	395,349	311,092	723,260	568,870
Subscription and services-based revenue
Revenue:
Revenue	134,332	59,151	231,386	108,211
Cost of revenue:
Cost of revenue	39,784	17,116	70,152	32,992
Hardware revenue
Revenue:
Revenue	18,362	10,289	32,779	19,305
Cost of revenue:
Cost of revenue	25,536	14,173	45,238	26,835
Bitcoin revenue
Revenue:
Revenue	37,016	0	71,111	0
Cost of revenue:
Cost of revenue	36,596	0	70,468	0
Technology assets
Cost of revenue:
Amortization of acquired technology	1,857	1,695	3,437	3,502
Customer assets
Operating expenses:
Amortization of acquired customer assets	$ 672	$ 222	$ 941	$ 427

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (5,906)	$ (15,962)	$ (29,892)	$ (31,052)
Net foreign currency translation adjustments	(2,944)	430	(2,395)	1,187
Net unrealized gain (loss) on revaluation of intercompany loans	(458)	432	207	403
Net unrealized gain (loss) on marketable securities	240	(139)	(950)	(120)
Total comprehensive loss	$ (9,068)	$ (15,239)	$ (33,030)	$ (29,582)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (29,892)	$ (31,052)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	22,488	18,562
Non-cash interest and other expense	11,855	5,680
Share-based compensation	98,943	71,263
Replacement stock awards issued in connection with acquisition	757	0
Recovery of common stock in connection with indemnification settlement agreement	(2,745)	0
Transaction, loan and advance losses	40,007	30,292
Deferred provision (benefit) for income taxes	(688)	99
Changes in operating assets and liabilities:
Settlements receivable	(191,987)	8,934
Customer funds	(105,813)	(30,022)
Purchase of loans held for sale	(734,251)	(570,819)
Sales and principal payments of loans held for sale	716,950	560,209
Other current assets	(33,495)	(2,201)
Other non-current assets	(9,696)	(110)
Accounts payable	(9,716)	143
Customers payable	267,746	34,149
Settlements payable	25,828	(9,317)
Charge-offs to accrued transaction losses	(26,030)	(22,243)
Accrued expenses	6,083	17,000
Other current liabilities	18,008	4,327
Other non-current liabilities	6,680	5,696
Net cash provided by operating activities	71,032	90,590
Cash flows from investing activities:
Purchase of marketable securities	(165,024)	(314,055)
Proceeds from maturities of marketable securities	79,273	52,064
Proceeds from sale of marketable securities	56,259	21,730
Purchase of property and equipment	(23,143)	(13,883)
Purchase of intangible assets	(1,584)	0
Business combinations, net of cash acquired	(111,828)	(1,600)
Net cash used in investing activities	(166,047)	(255,744)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes, net	855,663	428,250
Purchase of convertible senior note hedges	(172,586)	(92,136)
Proceeds from issuance of warrants	112,125	57,244
Settlement of deferred purchase consideration	(640)	0
Payment for termination of Starbucks warrant	0	(54,808)
Principal payments on capital lease obligation	(1,375)	(634)
Proceeds from the exercise of stock options and purchases under the employee stock purchase plan, net	67,199	89,863
Payments for tax withholding related to vesting of restricted stock units	(68,575)	0
Net cash provided by financing activities	791,811	427,779
Effect of foreign exchange rate on cash and cash equivalents	(3,505)	2,331
Net increase in cash, cash equivalents and restricted cash	693,291	264,956
Cash, cash equivalents and restricted cash, beginning of period	735,081	488,745
Cash, cash equivalents and restricted cash, end of period	$ 1,428,372	$ 753,701

DESCRIPTION OF BUSINESS AND SUM

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2018
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 help sellers start, run, and grow their businesses. Square enables sellers to accept card payments and also provides reporting and analytics, next-day settlement, and chargeback protection. 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. The Cash App is an easy way to send, spend, and receive money, and Caviar is a food-ordering platform. Square was founded in 2009 and is headquartered in San Francisco, with offices in the United States, Canada, Japan, Australia, Ireland, and the UK. 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, 2017 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 loss, and cash flows for the interim periods. All intercompany transactions and balances have been eliminated in consolidation. The interim results for the three and six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 , 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 “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Quantitative and Qualitative Disclosures About Market Risk,” and the Consolidated Financial Statements and notes thereto included in Items 7, 7A, and 8, respectively, in the Company's Annual Report on Form 10-K for the year ended December 31, 2017 . Use of Estimates The preparation of the Company’s 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 past experience and other assumptions that the Company believes are reasonable under the circumstances, and the Company evaluates these estimates on an ongoing basis. Estimates, judgments, and assumptions in these consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, valuation of the debt component of convertible senior notes, valuation of loans held for sale, goodwill, acquired intangible assets and deferred revenue, income and other taxes, and share-based compensation. Concentration of Credit Risk For the three and six months ended June 30, 2018 and 2017 , the Company had no customer that accounted for greater than 10% of total net revenue. The Company had three third-party payment processors that represented approximately 46% , 43% , and 7% of settlements receivable as of June 30, 2018 . The same three parties represented approximately 46% , 42% , and 8% of settlements receivable as of December 31, 2017 . 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 securities, settlements receivables, customer funds, 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 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 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. Accounting Policies Except for the adoption of ASC 606, Revenue from Contracts with Customers (ASC 606) , described in Note 2, and the accounting policy on cryptocurrency transactions, described below, there have been no material changes to the Company’s accounting policies during the six months ended June 30, 2018 , as compared to the accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Cryptocurrency transactions During the fourth quarter of 2017, the Company started offering its Cash App customers the ability to purchase bitcoin, a cryptocurrency denominated asset, from the Company. The Company purchases bitcoin from private broker dealers or from customers. Upon purchase, the Company records the cost of bitcoin within other current assets in its consolidated balance sheets. Upon sale, the Company records the total sale amount received from customers as bitcoin revenue and the associated cost as cost of revenue. The carrying value of bitcoin held by the Company was $0.4 million and $0.3 million as of June 30, 2018 and December 31, 2017 , respectively. The Company assesses the carrying value of bitcoin held by the Company at each reporting date and records an impairment charge if the cost exceeds the fair value. Losses on bitcoin for the three and six months ended June 30, 2018 , were insignificant. Recent Accounting Pronouncements Recently issued accounting pronouncements not yet adopted In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases , which will require, among other items, lessees to recognize a right of use asset and a related lease liability for most leases on the balance sheet. Qualitative and quantitative disclosures will be enhanced to better understand the amount, timing and uncertainty of cash flows arising from leases. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The new standard should be applied on a modified retrospective basis. The Company does not plan to early adopt this guidance. The Company’s operating leases primarily comprise of office spaces, with the most significant leases relating to corporate headquarters in San Francisco and an office in New York. While the Company continues to evaluate the impact of adopting this guidance on its consolidated financial statements, it does expect to record material right to use assets and related lease liabilities on its consolidated balance sheets upon adoption, which will increase total assets and liabilities. In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments , which requires measurement and recognition of expected credit losses for financial assets held. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact this new guidance may have on the consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment . The new guidance eliminates the requirement to calculate the implied fair value of goodwill assuming a hypothetical purchase price allocation (i.e., Step 2 of the goodwill impairment test) to measure a goodwill impairment charge. Instead, entities will record an impairment charge based on the excess of a reporting unit’s carrying amount over its fair value, not to exceed the carrying amount of goodwill. This standard should be adopted when the Company performs its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted. The amendments should be applied on a prospective basis. The Company does not expect the adoption of this guidance to have a material the impact on the consolidated financial statements and related disclosures. In March 2017, the FASB issued ASU No. 2017-08, Premium Amortization on Purchased Callable Debt Securities, which amends the amortization period for certain purchased callable debt securities held at a premium, shortening such period to the earliest call date. This standard is effective for annual periods beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The amendments in this guidance should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The Company is currently evaluating the impact this new guidance may have on the consolidated financial statements and related disclosures. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . When the Tax Cuts and Jobs Act of 2017 was enacted in December 2017, there was a valuation allowance on the deferred tax assets included within the Company's accumulated other comprehensive income; therefore no tax expense resulted from the change in the federal income tax rate. This guidance allows companies to reclassify such tax effects from accumulated other comprehensive income to retained earnings. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures. In February 2018, the FASB issued ASU 2018-03, Recognition and Measurement of Financial Assets and Financial Liabilities. This guidance clarifies that an entity that uses the measurement alternative for equity securities without readily determinable fair values can change its measurement approach to fair value. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years beginning after June 15, 2018. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures.

REVENUE

REVENUE	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE Adoption of ASC 606, Revenue from Contracts with Customers On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts are not adjusted and continue to be reported in accordance with the Company's historic revenue recognition methodology under ASC 605, Revenue Recognition . The Company recorded a net reduction to retained earnings of $4.6 million as of January 1, 2018, due to the cumulative impact of adopting ASC 606, primarily related to the effect on revenue and associated cost of revenue from hardware sold through the retail distribution channels and hardware installment sales. The impact to revenue for the three and six months ended June 30, 2018 was an increase of $2.4 million and $3.7 million , respectively, as a result of applying ASC 606. For the three months ended June 30, 2018 , the revenue recognized from contracts with customers was $792.3 million and revenue from other sources was $22.7 million . For the six months ended June 30, 2018 , the revenue recognized from contracts with customers was $1,441.0 million and revenue from other sources was $42.5 million . Impairment losses arising from contracts with customers were $0.9 million and $1.8 million for the three and six months ended June 30, 2018 , respectively. The impact of adoption of ASC 606 on the Company's condensed consolidated statement of operations was as follows (in thousands): Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 As reported Balances without adoption Effect of change As reported Balances without adoption Effect of change Impact on the Condensed Consolidated Statement of Operations: Subscription and services-based revenue $ 134,332 $ 134,240 $ 92 $ 231,386 $ 231,235 $ 151 Hardware revenue 18,362 16,079 2,283 32,779 29,233 3,546 Subscription and services-based costs 39,784 39,784 — 70,152 70,152 — Hardware costs $ 25,536 $ 22,939 $ 2,597 $ 45,238 $ 41,696 $ 3,542 The impact of adoption of ASC 606 on the Company's condensed consolidated balance sheets was as follows (in thousands): June 30, 2018 As reported Balances without adoption Effect of change Impact on the Condensed Consolidated Balance Sheets: Other current assets $ 120,250 $ 131,464 $ (11,214 ) Other current liabilities 60,635 67,486 (6,851 ) Other non-current assets 40,995 42,570 (1,575 ) Other non-current liabilities $ 85,851 $ 87,282 $ (1,431 ) Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The Company's contracts with customers generally do not include multiple performance obligations, except for domain name registration offered with website hosting services sold after May 31, 2018 following the acquisition of Weebly (see Note 7 , Acquisitions ). The following table presents the Company's revenue from contracts with customers disaggregated by revenue source (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Revenue from Contracts with Customers: Transaction-based revenue $ 625,228 $ 482,065 $ 1,148,265 $ 885,543 Subscription and services-based revenue 111,670 59,151 188,885 108,211 Hardware revenue $ 18,362 $ 10,289 $ 32,779 $ 19,305 Bitcoin revenue $ 37,016 $ — $ 71,111 $ — Transaction-based revenue The Company charges its sellers a transaction fee for managed payments solutions that is generally calculated as a percentage of the total transaction amount processed. The Company selectively offers custom pricing for certain sellers. The Company collects the transaction amount from the seller's customer's bank, net of acquiring interchange and assessment fees, processing fees, and bank settlement fees paid to third-party payment processors and financial institutions. The Company retains its fees and remits the net amount to the sellers. The Company acts as the merchant of record for its sellers and works directly with payment card networks and banks so that its sellers do not need to manage the complex systems, rules, and requirements of the payments industry. The Company satisfies its performance obligations and therefore recognizes the transaction fees as revenue upon authorization of a transaction by the seller's customer's bank. Revenue is recognized net of refunds, which arise from reversals of transactions initiated by sellers. The transaction fees collected from sellers are recognized as revenue on a gross basis as the Company is the principal in the delivery of the managed payments solutions to the sellers. The Company has concluded it is the principal because it controls the services before delivery to the seller, it is primarily responsible for the delivery of the services, and it has discretion in setting prices charged to sellers. As the merchant of record, Square is liable for settlement of the transactions the Company processes for its sellers, which is recorded as cost of revenue. Subscription and services-based revenue Subscription and services-based revenue is primarily comprised of revenue the Company generates from Instant Deposit and Cash Card, Caviar, website hosting and domain name registration services, and various other software as a service (SaaS) products. Instant Deposit is a functionality within the Cash App and the Company's managed payments solution that enables customers, including individuals and sellers, to instantly deposit funds into their bank accounts. The Company charges a per transaction fee which is recognized as revenue when customers instantly deposit funds to their bank account. The Company also offers Cash App customers the ability to use funds stored in the Cash App via a Visa prepaid card, for which the Company charges a per transaction fee that is recorded as revenue. Caviar is a food ordering platform that facilitates food delivery services for restaurants. The Company's performance obligation is the delivery of food orders from restaurants to customers. The Company charges fees to restaurants, as sellers, and also charges delivery and service fees to individual and corporate customers. All fees are billed upon delivery of food orders, when the Company considers that it has satisfied its performance obligations. Revenue is also recognized upon delivery of the food orders, net of refunds. Refunds are estimated based on historical experience. Following the acquisition of Weebly, the Company offers customers website hosting services for a fee that is generally billed at inception. The Company also acts as a reseller of domain names registration services for a registrar for a fee, which is also generally billed at inception. The Company considers that it satisfies its performance obligations over time and as such recognizes revenue ratably over the term of the relevant arrangements, which vary from one month to twenty four months for website hosting, and one year to ten years for domain name registration. SaaS represents software products and solutions that provide customers with access to various technologies for a fee which is recognized ratably as the service is provided. The Company's contracts with customers are generally for a term of one month and renew automatically each month. The Company invoices its customers monthly. The Company considers that it satisfies its performance obligations over time each month as it provides the SaaS services to customers and hence recognizes revenue ratably over the month. Hardware revenue The Company generates revenue through the sale of hardware through e-commerce and through its retail distribution channels. The Company satisfies its performance obligation upon delivery of hardware to its customers who include end user customers, distributors, and retailers. The Company may at times offer concessions to customers and also allow for customer returns, which are accounted for as variable consideration. The Company estimates these amounts based on historical experience and reduces revenue recognized. The Company invoices end user customers upon delivery of the products to customers, and payments from such customers are due upon invoicing. Distributors and retailers have payment terms that range from 30 to 90 days after delivery. The Company offers hardware installment sales to customers with terms ranging from three to twenty four months. The Company allocates a portion of the consideration received from these arrangements to a financing component when it determines that a significant financing component exists. The financing component is subsequently recognized as financing revenue over the terms of the arrangement with the customer. Bitcoin revenue During the fourth quarter of 2017, the Company started offering its Cash App customers the ability to purchase bitcoin, a cryptocurrency denominated asset, from the Company. The Company satisfies its performance obligation and records revenue when bitcoin is transferred to the customer's account. Arrangements with Multiple Performance Obligations The Company also offers its customers the option to buy website hosting bundled with domain name registration, and infrequently the Company has offered its hardware customers free managed payments solutions with the purchase of its hardware as part of a marketing promotion. For such arrangements, the Company allocates revenue to each performance obligation based on its relative standalone selling price. We generally determine standalone selling prices based on the prices charged to customers since the Company's products and services are normally sold on a stand alone basis. Deferred Revenue Deferred revenue is comprised of unearned revenue related to managed payments services offered in conjunction with hardware sales for which the cash payments from customers are received and due upon the sale of the hardware. Deferred revenue also includes payments for website hosting and domain name registration received from customers at inception of the arrangements prior to the services being rendered. The deferred revenue balances were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Deferred revenue, beginning of the period $ 3,353 $ 2,965 $ 5,893 $ 5,407 Less: accumulative adjustment for adoption of ASC 606 — — (4,303 ) — Deferred revenue, beginning of the period, as adjusted 3,353 2,965 1,590 5,407 Deferred revenue, end of the period 27,155 4,523 27,155 4,523 Deferred revenue arising from business combination 22,800 — 22,800 — Revenue recognized in the period from amounts included in deferred revenue at the beginning of the period 1,975 925 1,095 5,257 Practical Expedients The Company does not recognize a financing component for hardware installment sales that have a term of one year or less.

RESTRICTED CASH

RESTRICTED CASH	6 Months Ended
	Jun. 30, 2018
Cash and Cash Equivalents [Abstract]
RESTRICTED CASH	RESTRICTED CASH As of June 30, 2018 and December 31, 2017 , restricted cash of $27.5 million and $28.8 million , respectively, is related to pledged cash deposited into savings accounts at the financial institutions that process the Company's sellers' payment transactions and as collateral pursuant to an agreement with the originating bank for the Company's loan product. The Company uses the restricted cash to secure letters of credit with the financial institution to provide collateral for cash flow timing differences in the processing of these payments. The Company has recorded this amount as a current asset on the consolidated balance sheets due to the short-term nature of these cash flow timing differences and that there is no minimum time frame during which the cash must remain restricted. Additionally, this balance includes certain amounts held as collateral pursuant to multi-year lease agreements, discussed in the paragraph below, which we expect to become unrestricted within the next year. As of June 30, 2018 and December 31, 2017 , the remaining restricted cash of $12.9 million and $9.8 million , respectively, is primarily related to cash deposited into money market funds that is used as collateral pursuant to multi-year lease agreements (Note 17 ). This includes $3.1 million arising from the acquisition of Weebly (Note 7). The Company has recorded this amount as a non-current asset on the consolidated balance sheets as the terms of the related leases extend beyond one year.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS The Company measures its cash equivalents and short-term and long-term investments at fair value. The Company classifies its cash equivalents and short-term and long-term investments within Level 1 or Level 2 of the fair value hierarchy because the Company values these investments using quoted market prices or alternative pricing sources and models utilizing market observable inputs. The Company’s financial assets and liabilities that are measured at fair value on a recurring basis are classified as follows (in thousands): June 30, 2018 December 31, 2017 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash and Cash Equivalents: Money market funds $ 1,031,129 $ — $ — $ 387,698 $ — $ — U.S. agency securities — 35,086 — — — — Commercial paper — — — — 24,695 — U.S. government securities 34,978 — — — — — Short-term securities: U.S. agency securities — 14,997 — — 15,083 — Corporate bonds — 57,371 — — 57,798 — Commercial paper — — — — 17,428 — Municipal securities — 23,740 — — 23,700 — U.S. government securities 137,491 — — 55,567 — — Long-term securities: U.S. agency securities — 10,076 — — 20,169 — Corporate bonds — 52,567 — — 91,413 — Municipal securities — 19,444 — — 26,224 — U.S. government securities 86,063 — — 65,861 — — Total $ 1,289,661 $ 213,281 $ — $ 509,126 $ 276,510 $ — The carrying amounts of certain financial instruments, including cash equivalents, settlements receivable, customer funds, accounts payable, customers payable, and settlements payable, approximate their fair values due to their short-term nature. The Company estimates the fair value of its convertible senior notes based on their last actively traded prices (Level 1) or market observable inputs (Level 2). The estimated fair value and carrying value of the convertible senior notes were as follows (in thousands): June 30, 2018 December 31, 2017 Carrying Value Fair Value (Level 2) Carrying Value Fair Value (Level 2) 2023 Notes $ 704,021 $ 924,936 $ — $ — 2022 Notes 367,416 1,188,686 358,572 719,356 Total $ 1,071,437 $ 2,113,622 $ 358,572 $ 719,356 Loans held for sale are recorded at the lower of amortized cost or fair value determined on an individual loan basis. To determine the fair value the Company utilizes industry-standard valuation modeling, such as discounted cash flow models, taking into account the estimated timing and amounts of periodic repayments. A summary of loans disclosed at fair value on a recurring basis is as follows (in thousands): June 30, 2018 December 31, 2017 Carrying Value Fair Value (Level 3) Carrying Value Fair Value (Level 3) Loans held for sale $ 85,040 $ 88,645 $ 73,420 $ 76,070 Total $ 85,040 $ 88,645 $ 73,420 $ 76,070 The Company recognizes a charge within transaction, loan and advance losses on the consolidated statement of operations whenever the amortized cost of a loan exceeds its fair value, with such charges being reversed for subsequent increases in fair value, but only to the extent that such reversals do not result in the amortized cost of a loan exceeding its fair value. For the three and six months ended June 30, 2018 , the Company recorded a charge for the excess of amortized cost over fair value of the loans of $3.2 million and $5.7 million , respectively. For both the three and six months ended June 30, 2017 , the Company recorded a charge for the excess of amortized cost over fair value of the loans of $2.7 million . If applicable, the Company will recognize transfers into and out of levels within the fair value hierarchy at the end of the reporting period in which the actual event or change in circumstance occurs. During the three and six months ended June 30, 2018 and 2017 , the Company did not have any transfers in or out of Level 1, Level 2, or Level 3 assets or liabilities.

INVESTMENTS

INVESTMENTS	6 Months Ended
	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS The Company determines the appropriate classification of its investments in marketable securities at the time of purchase and reevaluates such designation at each balance sheet date. The Company has classified and accounted for its marketable securities as available-for-sale. The Company's short-term and long-term investments as of June 30, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term securities: U.S. agency securities $ 14,978 $ 19 $ — $ 14,997 Corporate bonds 57,293 201 (123 ) 57,371 Commercial paper — — — — Municipal securities 23,720 30 (10 ) 23,740 U.S. government securities 137,499 78 (86 ) 137,491 Total $ 233,490 $ 328 $ (219 ) $ 233,599 Long-term securities: U.S. agency securities $ 10,096 $ — $ (20 ) $ 10,076 Corporate bonds 52,354 245 (32 ) 52,567 Municipal securities 19,483 10 (49 ) 19,444 U.S. government securities 86,086 88 (111 ) 86,063 Total $ 168,019 $ 343 $ (212 ) $ 168,150 The Company's short-term and long-term investments as of December 31, 2017 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term securities: U.S. agency securities $ 15,122 $ — $ (39 ) $ 15,083 Corporate bonds 57,855 22 (79 ) 57,798 Commercial paper 17,428 — — 17,428 Municipal securities 23,743 8 (51 ) 23,700 U.S. government securities 55,729 1 (163 ) 55,567 Total $ 169,877 $ 31 $ (332 ) $ 169,576 Long-term securities: U.S. agency securities $ 20,288 $ 2 $ (121 ) $ 20,169 Corporate bonds 91,959 25 (571 ) 91,413 Municipal securities 26,371 13 (160 ) 26,224 U.S. government securities 66,362 19 (520 ) 65,861 Total $ 204,980 $ 59 $ (1,372 ) $ 203,667 For the periods presented, gains or losses realized on the sale of investments were not material. Investments are reviewed periodically to identify possible other-than-temporary impairments. As the Company has the ability and intent to hold these investments with unrealized losses for a reasonable period of time sufficient for the recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired for any of the periods presented. The contractual maturities of the Company's short-term and long-term investments as of June 30, 2018 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 233,490 $ 233,599 Due in one to five years 168,019 168,150 Total $ 401,509 $ 401,749

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	6 Months Ended
	Jun. 30, 2018
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET The following is a summary of property and equipment, less accumulated depreciation and amortization (in thousands): June 30, December 31, Leasehold improvements $ 94,241 $ 77,073 Computer equipment 81,763 66,186 Capitalized software 45,927 35,063 Office furniture and equipment 18,231 14,490 240,162 192,812 Less: Accumulated depreciation and amortization (118,454 ) (101,316 ) Property and equipment, net $ 121,708 $ 91,496 Depreciation and amortization expense on property and equipment was $9.3 million and $17.5 million for the three and six months ended June 30, 2018 , respectively. Depreciation and amortization expense on property and equipment was $7.2 million and $14.5 million for the three and six months ended June 30, 2017 , respectively.

ACQUISITIONS

ACQUISITIONS	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Weebly, Inc. On May 31, 2018 , the Company acquired 100% of the outstanding shares of Weebly, a technology company that offers customers website hosting and domain name registration solutions. The acquisition of Weebly will enable the Company to combine Weebly’s web presence tools with the Company's in-person and online offerings to create a cohesive solution for sellers to start or grow an omnichannel business. The acquisition will also expand the Company’s customer base globally and add a new recurring revenue stream. The purchase consideration was comprised of $131.9 million in cash and 2,406,071 shares of the Company’s Class A common stock with an aggregate fair value of $139.4 million based on the closing price of the Company’s Class A common stock on the acquisition date. As part of the acquisition, the Company paid an aggregate of $17.7 million in cash and shares to settle outstanding vested and unvested employee options, of which $2.6 million was accounted for as post-combination compensation expense and is excluded from the purchase consideration. Third-party acquisition-related costs of $1.2 million were recognized in general and administrative expense for both the three and six months ended June 30, 2018 . The results of Weebly's operations have been included in the consolidated financial statements since the closing date. The acquisition was accounted for as a business combination. This method requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date and that the difference between the fair value of the consideration paid for the acquired entity and the fair value of the net assets acquired be recorded as goodwill, which is not amortized but is tested at least annually for impairment. The table below summarizes the consideration paid for Weebly and the preliminary assessment of the fair value of the assets acquired and liabilities assumed at the closing date (in thousands, except share data). The Company is in the process of completing the valuation of the acquired intangible assets and deferred revenue and is evaluating contingencies and tax effects related to the acquisition. Accordingly, the preliminary values reflected in the table are subject to change. Consideration: Cash $ 131,860 Stock (2,406,071 shares of common stock) 139,396 $ 271,256 Recognized amounts of identifiable assets acquired and liabilities assumed: Current assets (inclusive of cash acquired of $25,758) $ 44,685 Intangible customer assets 42,700 Intangible technology assets 14,900 Intangible trade name 11,300 Intangible other assets 961 Total liabilities assumed (including deferred revenue of $22,800) (32,824 ) Total identifiable net assets acquired 81,722 Goodwill 189,534 Total $ 271,256 As of June 30, 2018, $19.9 million of cash and 372,578 shares of the total consideration were withheld as security for indemnification obligations related to general representations and warranties, in addition to certain potential tax exposures. . Goodwill from the Weebly acquisition is primarily attributable to the value of expected synergies created by incorporating Weebly solutions into the Company's technology platform and the value of the assembled workforce. None of the goodwill generated from the Weebly acquisition or the acquired intangible assets are expected to be deductible for tax purposes. Additionally the acquisition would have resulted in recognition of deferred tax assets arising mainly from the net of deferred tax assets from acquired net operating losses (NOLs) and research and development credits, and deferred tax liabilities associated with intangible assets and deferred revenue. However, the realization of such deferred tax assets depends primarily on the Company's post-acquisition ability to generate taxable income in future periods. Accordingly, a valuation allowance was recorded against the net acquired deferred tax asset in accounting for the acquisition. The results of operations from the Weebly acquisition have been consolidated with those of the Company beginning as of the acquisition date. The acquisition of Weebly did not have a material impact on the Company's reported revenue or net loss amounts for any period presented. Accordingly, pro forma financial information has not been presented. Other acquisitions The Company also spent an aggregate of $9.9 million , net of cash acquired, in connection with other immaterial acquisitions during the six months ended June 30, 2018, which resulted in the recognition of additional intangible assets and goodwill. Pro forma financial information has not been presented for any of our acquisitions as the impact to our consolidated financial statements was not material.

GOODWILL

GOODWILL	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL Goodwill is recorded when the consideration paid for an acquisition of a business exceeds the fair value of identifiable net tangible and intangible assets acquired. The change in carrying value of goodwill in the period was as follows (in thousands): Balance at December 31, 2017 $ 58,327 Acquisitions completed during the six months ended June 30, 2018 197,329 Balance at June 30, 2018 $ 255,656 The Company performs a goodwill impairment test annually on December 31 and more frequently if events and circumstances indicate that the asset might be impaired. For the periods presented, the Company had recorded no impairment charges.

ACQUIRED INTANGIBLE ASSETS

ACQUIRED INTANGIBLE ASSETS	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
ACQUIRED INTANGIBLE ASSETS	ACQUIRED INTANGIBLE ASSETS The Company entered into two transactions accounted for as business combinations during the quarter ended June 30, 2018, that involved the acquisition of intangible assets. Refer to Note 7 for further details. The following table presents the detail of acquired intangible assets as of the periods presented (in thousands): Balance at June 30, 2018 Cost Accumulated Amortization Net Patents $ 1,285 $ (611 ) $ 674 Technology assets 45,978 (24,766 ) 21,212 Customer assets 57,109 (5,481 ) 51,628 Trade name 11,300 (235 ) 11,065 Other 961 (26 ) 935 Total $ 116,633 $ (31,119 ) $ 85,514 Balance at December 31, 2017 Cost Accumulated Amortization Net Patents $ 1,285 $ (559 ) $ 726 Technology assets 29,158 (21,329 ) 7,829 Customer assets 10,319 (4,540 ) 5,779 Total $ 40,762 $ (26,428 ) $ 14,334 The weighted average amortization periods for acquired patents, acquired technology, customer intangible assets, and acquired trade name are approximately 13 years , 5 years , 11 years and 4 years , respectively. All intangible assets are amortized over their estimated useful lives. The changes to the carrying value of intangible assets were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Acquired intangible assets, net, beginning of the period $ 14,138 $ 18,395 $ 14,334 $ 19,292 Acquisitions 74,192 — 75,871 1,224 Amortization expense 2,816 1,943 4,691 4,064 Acquired intangible assets, net, end of the period $ 85,514 $ 16,452 $ 85,514 $ 16,452 The total estimated future amortization expense of these intangible assets as of June 30, 2018 is as follows (in thousands): 2018 (remaining 6 months) $ 7,863 2019 13,843 2020 11,638 2021 10,440 2022 8,511 Thereafter 33,219 Total $ 85,514

OTHER CONSOLIDATED BALANCE SHEE

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT)	OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) Other Current Assets The following table presents the detail of other current assets (in thousands): June 30, December 31, Inventory, net $ 22,041 $ 16,777 Processing costs receivable 33,861 21,083 Prepaid expenses 16,663 14,473 Accounts receivable, net 17,895 8,606 Deferred hardware costs (i) — 7,931 Deferred magstripe reader costs (ii) 3,034 2,469 Prepaid compensation, current (iii) 5,940 — Other 20,816 15,115 Total $ 120,250 $ 86,454 (i) The deferred hardware costs represented costs associated with hardware sold through the retail distribution channels. The adoption of ASC 606 on January 1, 2018, has resulted in the recognition of such costs upon delivery of the hardware to the distribution channel. (ii) The Company capitalizes the cost of its magstripe readers, including packaging and shipping costs, held on-hand by the Company as of each consolidated balance sheet date. Once the readers are shipped to a third-party distributor or an end-customer, they are recorded as marketing expense on the consolidated statements of operations. (iii) Prepaid compensation relates to cash transferred by the Company to an escrow agent in connection with a business combination that will be paid to officers of the acquiree over time as they provide services to the Company. Accrued Expenses The following table presents the detail of accrued expenses (in thousands): June 30, December 31, Accrued payroll $ 10,229 $ 9,103 Accrued professional fees 9,168 5,638 Accrued advertising and other marketing 11,961 6,723 Processing costs payable 11,205 10,145 Accrued non income tax liabilities 7,504 6,155 Accrued hardware costs 1,806 2,496 Other accrued liabilities 22,943 12,020 Total $ 74,816 $ 52,280 Other Current Liabilities The following table presents the detail of other current liabilities (in thousands): June 30, December 31, Square Capital payable (iv) $ 10,301 $ 7,671 Square Payroll payable (v) 6,494 2,850 Deferred revenue, current 24,062 5,893 Deferred rent, current 3,691 3,311 Accrued redemptions 1,110 1,036 Other 14,977 7,606 Total $ 60,635 $ 28,367 (iv) Square Capital payable represents unpaid amounts arising from the purchase of loans or loan repayments collected on behalf of third parties. (v) Square Payroll payable represents amounts received from Square Payroll product customers that will be utilized to settle the customers employee payroll and related obligations. OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) Other Non-Current Assets The following table presents the detail of other non-current assets (in thousands): June 30, December 31, Investment in privately held entity $ 25,000 $ 25,000 Prepaid compensation, non-current (i) 7,927 — Deposits 2,646 2,738 Debt issuance costs 650 788 Deferred tax assets 680 519 Other 4,092 2,305 Total $ 40,995 $ 31,350 (i) Prepaid compensation relates to cash transferred by the Company to an escrow agent in connection with a business combination that will be paid to officers of the acquiree over time as they provide services to the Company. Other Non-Current Liabilities The following table presents the detail of other non-current liabilities (in thousands): June 30, December 31, Statutory liabilities (ii) $ 47,423 $ 40,768 Deferred rent, non-current 21,479 20,349 Deferred purchase consideration 3,900 — Deferred revenue, non-current 3,093 432 Deferred tax liabilities 148 644 Other 9,808 7,345 Total $ 85,851 $ 69,538 (ii) Statutory liabilities represent loss contingencies that may arise from the Company's interpretation and application of certain guidelines and rules issued by various federal, state, local, and foreign regulatory authorities.

OTHER CONSOLIDATED BALANCE SH17

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT)	OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) Other Current Assets The following table presents the detail of other current assets (in thousands): June 30, December 31, Inventory, net $ 22,041 $ 16,777 Processing costs receivable 33,861 21,083 Prepaid expenses 16,663 14,473 Accounts receivable, net 17,895 8,606 Deferred hardware costs (i) — 7,931 Deferred magstripe reader costs (ii) 3,034 2,469 Prepaid compensation, current (iii) 5,940 — Other 20,816 15,115 Total $ 120,250 $ 86,454 (i) The deferred hardware costs represented costs associated with hardware sold through the retail distribution channels. The adoption of ASC 606 on January 1, 2018, has resulted in the recognition of such costs upon delivery of the hardware to the distribution channel. (ii) The Company capitalizes the cost of its magstripe readers, including packaging and shipping costs, held on-hand by the Company as of each consolidated balance sheet date. Once the readers are shipped to a third-party distributor or an end-customer, they are recorded as marketing expense on the consolidated statements of operations. (iii) Prepaid compensation relates to cash transferred by the Company to an escrow agent in connection with a business combination that will be paid to officers of the acquiree over time as they provide services to the Company. Accrued Expenses The following table presents the detail of accrued expenses (in thousands): June 30, December 31, Accrued payroll $ 10,229 $ 9,103 Accrued professional fees 9,168 5,638 Accrued advertising and other marketing 11,961 6,723 Processing costs payable 11,205 10,145 Accrued non income tax liabilities 7,504 6,155 Accrued hardware costs 1,806 2,496 Other accrued liabilities 22,943 12,020 Total $ 74,816 $ 52,280 Other Current Liabilities The following table presents the detail of other current liabilities (in thousands): June 30, December 31, Square Capital payable (iv) $ 10,301 $ 7,671 Square Payroll payable (v) 6,494 2,850 Deferred revenue, current 24,062 5,893 Deferred rent, current 3,691 3,311 Accrued redemptions 1,110 1,036 Other 14,977 7,606 Total $ 60,635 $ 28,367 (iv) Square Capital payable represents unpaid amounts arising from the purchase of loans or loan repayments collected on behalf of third parties. (v) Square Payroll payable represents amounts received from Square Payroll product customers that will be utilized to settle the customers employee payroll and related obligations. OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) Other Non-Current Assets The following table presents the detail of other non-current assets (in thousands): June 30, December 31, Investment in privately held entity $ 25,000 $ 25,000 Prepaid compensation, non-current (i) 7,927 — Deposits 2,646 2,738 Debt issuance costs 650 788 Deferred tax assets 680 519 Other 4,092 2,305 Total $ 40,995 $ 31,350 (i) Prepaid compensation relates to cash transferred by the Company to an escrow agent in connection with a business combination that will be paid to officers of the acquiree over time as they provide services to the Company. Other Non-Current Liabilities The following table presents the detail of other non-current liabilities (in thousands): June 30, December 31, Statutory liabilities (ii) $ 47,423 $ 40,768 Deferred rent, non-current 21,479 20,349 Deferred purchase consideration 3,900 — Deferred revenue, non-current 3,093 432 Deferred tax liabilities 148 644 Other 9,808 7,345 Total $ 85,851 $ 69,538 (ii) Statutory liabilities represent loss contingencies that may arise from the Company's interpretation and application of certain guidelines and rules issued by various federal, state, local, and foreign regulatory authorities.

INDEBTEDNESS

INDEBTEDNESS	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
INDEBTEDNESS	INDEBTEDNESS Revolving Credit Facility In November 2015 , the Company entered into a revolving credit agreement with certain lenders, which extinguished the prior revolving credit agreement and provided for a $375.0 million revolving secured credit facility maturing in November 2020 . This revolving credit agreement is secured by certain tangible and intangible assets. Loans under the credit facility bear interest at the Company’s option of (i) a base rate based on the highest of the prime rate, the federal funds rate plus 0.50% , and an adjusted LIBOR rate for a one-month interest period, in each case plus a margin ranging from 0.00% to 1.00% , or (ii) an adjusted LIBOR rate plus a margin ranging from 1.00% to 2.00% . This margin is determined based on the Company’s total leverage ratio for the preceding four fiscal quarters. The Company is obligated to pay other customary fees for a credit facility of this size and type including an annual administrative agent fee of $0.1 million and an unused commitment fee of 0.15% . To date no funds have been drawn under the credit facility, with $375.0 million remaining available. The Company paid $0.1 million and $0.3 million in unused commitment fees during both the three and six months ended June 30, 2018 and 2017 , respectively. As of June 30, 2018 , the Company was in compliance with all financial covenants associated with this credit facility. Convertible Senior Notes due in 2023 On May 25, 2018, the Company issued an aggregate principal amount of $750.0 million of convertible senior notes and an additional 15% or $112.5 million pursuant to the exercise in full of the option to the initial purchaser to cover over-allotments (2023 Notes). The 2023 Notes mature on May 15, 2023, unless earlier converted or repurchased, and bear interest at a rate of 0.50% payable semi-annually on May 15 and November 15 of each year. The 2023 Notes are convertible at an initial conversion rate of 12.8456 shares of the Company's Class A common stock per $1,000 principal amount of 2023 Notes, which is equivalent to an initial conversion price of approximately $77.85 per share of Class A common stock. Holders may convert their 2023 Notes at any time prior to the close of business on the business day immediately preceding February 15, 2023 only under the following circumstances: (1) during any calendar quarter commencing after September 30, 2018 (and only during such calendar quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the measurement period) in which the trading price (as defined in the indenture governing the 2023 Notes) per $1,000 principal amount of 2023 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events, including certain distributions, the occurrence of a fundamental change (as defined in the indenture governing the 2023 Notes) or a transaction resulting in the Company’s Class A common stock converting into other securities or property or assets. On or after February 15, 2023, up until the close of business on the second scheduled trading day immediately preceding the maturity date, a holder may convert all or any portion of its 2023 Notes regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its Class A common stock, or a combination of cash and shares of its Class A common stock, at the Company’s election. It is the Company’s current intent and policy to settle conversions through combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of 2023 Notes. In accounting for the issuance of the 2023 Notes, the Company separated the 2023 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $155.3 million and was determined by deducting the fair value of the liability component from the par value of the 2023 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount ("debt discount") is amortized to interest expense over the term of the 2023 Notes at an effective interest rate of 4.69% over the contractual terms of the Notes. Debt issuance costs related to the 2023 Notes comprising of discounts and commissions payable to the initial purchasers of $6.0 million and third party offering costs amounted to $0.8 million . The Company allocated the total amount incurred to the liability and equity components of the 2023 Notes based on their relative values. Issuance costs attributable to the liability component were $5.6 million and will be amortized to interest expense using the effective interest method over the contractual term. Issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity. Convertible Senior Notes due in 2022 On March 6, 2017, the Company issued an aggregate principal amount of $400.0 million of convertible senior notes and an additional 10% or $40.0 million pursuant to the exercise in full of the option to the initial purchasers to cover over-allotments (2022 Notes). The 2022 Notes mature on March 1, 2022, unless earlier converted or repurchased, and bear interest at a rate of 0.375% payable semi-annually on March 1 and September 1 of each year. The 2022 Notes are convertible at an initial conversion rate of 43.5749 shares of the Company's Class A common stock per $1,000 principal amount of 2022 Notes, which is equivalent to an initial conversion price of approximately $22.95 per share of Class A common stock. Holders may convert their 2022 Notes at any time prior to the close of business on the business day immediately preceding December 1, 2021 only under the following circumstances: (1) during any calendar quarter (and only during such calendar quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the measurement period) in which the trading price (as defined in the indenture governing the 2022 Notes) per $1,000 principal amount of 2022 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events, including certain distributions, the occurrence of a fundamental change (as defined in the indenture governing the 2022 Notes) or a transaction resulting in the Company’s Class A common stock converting into other securities or property or assets. On or after December 1, 2021, up until the close of business on the second scheduled trading day immediately preceding the maturity date, a holder may convert all or any portion of its 2022 Notes regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its Class A common stock, or a combination of cash and shares of its Class A common stock, at the Company’s election. It is the Company’s current intent and policy to settle conversions through combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of 2022 Notes. The circumstances required to allow the holders to convert their 2022 Notes were met for the quarters commencing January 1, 2018, April 1, 2018 and July 1, 2018 respectively. In late July 2018, certain holders of the 2022 Notes informed the Company of their intention to convert $45 million in principal amount. In accounting for the issuance of the 2022 Notes, the Company separated the 2022 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $86.2 million and was determined by deducting the fair value of the liability component from the par value of the 2022 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The debt discount is amortized to interest expense over the term of the 2022 Notes at an effective interest rate of 5.34% over the contractual terms of the Notes. Debt issuance costs related to the 2022 Notes comprised of discounts and commissions payable to the initial purchasers of $11.0 million and third party offering costs of $0.8 million . The Company allocated the total amount incurred to the liability and equity components of the 2022 Notes based on their relative values. Issuance costs attributable to the liability component were $9.4 million and will be amortized to interest expense using the effective interest method over the contractual term. Issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity. The net carrying amount of the Notes were as follows (in thousands): Principal outstanding Unamortized debt discount Unamortized debt issuance costs Net carrying value June 30, 2018 2023 Notes 862,500 (152,955 ) (5,524 ) 704,021 2022 Notes 440,000 (65,414 ) (7,170 ) 367,416 Total 1,302,500 (218,369 ) (12,694 ) 1,071,437 December 31, 2017 2022 Notes 440,000 (73,384 ) (8,044 ) 358,572 The net carrying amount of the equity component of the Notes were as follows (in thousands): Amount allocated to conversion option Less: allocated issuance costs Equity component, net June 30, 2018 2023 Notes 155,250 (1,231 ) 154,019 2022 Notes 86,203 (2,302 ) 83,901 Total 241,453 (3,533 ) 237,920 December 31, 2017 2022 Notes 86,203 (2,302 ) 83,901 The Company recognized interest expense on the Notes as follows (in thousands, except for percentages): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Contractual interest expense $ 850 $ 413 $ 1,263 $ 526 Amortization of debt discount and issuance costs 6,830 4,221 11,223 5,611 Total $ 7,680 $ 4,634 $ 12,486 $ 6,137 The effective interest rate of the liability component is 4.69% and 5.34% for the 2023 Notes and 2022 Notes, respectively. Convertible Note Hedge and Warrant Transactions In connection with the offering of the 2023 Notes, the Company entered into convertible note hedge transactions (2023 convertible note hedges) with certain financial institution counterparties whereby the Company has the option to purchase a total of approximately 11.1 million shares of its Class A common stock at a price of approximately $77.85 per share. The total cost of the 2023 convertible note hedge transactions was $172.6 million . In addition, the Company sold warrants (2023 warrants) to the counterparties whereby the counterparties have the option to purchase a total of 11.1 million shares of the Company’s Class A common stock at a price of approximately $109.26 per share. The Company received $112.1 million in cash proceeds from the sale of the 2023 warrants. Taken together, the purchase of the 2023 convertible note hedges and sale of the 2023 warrants are intended to reduce dilution from the conversion of the 2023 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of the converted 2023 Notes, as the case may be, and to effectively increase the overall conversion price from approximately $77.85 per share to approximately $109.26 per share. As these instruments are considered indexed to the Company's own stock and are considered equity classified, the 2023 convertible note hedges and 2023 warrants are recorded in stockholders’ equity, are not accounted for as derivatives and are not remeasured each reporting period. The net costs incurred in connection with the 2023 convertible note hedge and 2023 warrant transactions were recorded as a reduction to additional paid-in capital on the condensed consolidated balance sheets. In connection with the offering of the 2022 Notes, the Company entered into convertible note hedge transactions (2022 convertible note hedges) with certain financial institution counterparties whereby the Company has the option to purchase a total of approximately 19.2 million shares of its Class A common stock at a price of approximately $22.95 per share. The total cost of the 2022 convertible note hedge transactions was $92.1 million . In addition, the Company sold warrants (2022 warrants) to the counterparties whereby the counterparties have the option to purchase a total of 19.2 million shares of the Company’s Class A common stock at a price of approximately $31.18 per share. The Company received $57.2 million in cash proceeds from the sale of the 2022 warrants. Taken together, the purchase of the 2022 convertible note hedges and sale of the 2022 warrants are intended to reduce dilution from the conversion of the 2022 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of the converted 2022 Notes, as the case may be, and to effectively increase the overall conversion price from approximately $22.95 per share to approximately $31.18 per share. As these instruments are considered indexed to the Company's own stock and are considered equity classified, the 2022 convertible note hedges and 2022 warrants are recorded in stockholders’ equity, are not accounted for as derivatives and are not remeasured each reporting period. The net costs incurred in connection with the 2022 convertible note hedge and 2022 warrant transactions were recorded as a reduction to additional paid-in capital on the condensed consolidated balance sheets.

ACCRUED TRANSACTION LOSSES

ACCRUED TRANSACTION LOSSES	6 Months Ended
	Jun. 30, 2018
Product Warranties Disclosures [Abstract]
ACCRUED TRANSACTION LOSSES	ACCRUED TRANSACTION LOSSES The Company is exposed to transaction losses due to chargebacks as a result of fraud or uncollectibility. The following table summarizes the activities of the Company’s reserve for transaction losses (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Accrued transaction losses, beginning of the period $ 28,309 $ 20,444 $ 26,893 $ 20,064 Provision for transaction losses 14,087 13,076 28,345 24,634 Charge-offs to accrued transaction losses (13,189 ) (11,065 ) (26,031 ) (22,243 ) Accrued transaction losses, end of the period $ 29,207 $ 22,455 $ 29,207 $ 22,455

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company recorded an income tax expense of $0.6 million and $0.8 million for the three and six months ended June 30, 2018 , respectively, compared to income tax expense of $0.5 million and $1.0 million for the three and six months ended June 30, 2017 , respectively. The income tax expense recorded for the three and six months ended June 30, 2018 was primarily due to state and foreign income tax expense offset by a release in the U.S. valuation allowance. The Company’s effective tax rate was (11.4)% and (2.7)% for the three and six months ended June 30, 2018 , respectively, compared to an effective tax rate of (3.0)% and (3.3)% for the three and six months ended June 30, 2017 , respectively. The difference between the effective tax rate and the federal statutory tax rate for the three and six months ended June 30, 2018 and June 30, 2017 primarily relates to the valuation allowance on the Company’s deferred tax assets. The Company’s effective tax rate may be subject to fluctuation during the year as new information is obtained, which may affect the assumptions used to estimate the annual effective tax rate, including factors such as the mix of forecasted pre-tax earnings in the various jurisdictions in which the Company operates, valuation allowances against deferred tax assets, the recognition and de-recognition of tax benefits related to uncertain tax positions, and changes in or the interpretation of tax laws in jurisdictions where the Company conducts business. As of June 30, 2018 , the Company retains a full valuation allowance on its deferred tax assets in the U.S. and certain foreign jurisdictions. The realization of the Company’s deferred tax assets depends primarily on its ability to generate taxable income in future periods. The amount of deferred tax assets considered realizable in future periods may change as management continues to reassess the underlying factors it uses in estimating future taxable income. The tax provision for the three and six months ended June 30, 2018 and June 30, 2017 , was calculated on a jurisdiction basis. The Company estimated the foreign income tax provision using the effective income tax rate expected to be applicable for the full year. On December 22, 2017, the SEC issued Staff Accounting Bulletin No. 118 to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act of 2017. The Company's accounting for all items is expected to be complete when the Company files its 2017 U.S. corporate income tax return 2018. Any differences between what was previously recorded and the final tax return amounts or estimates done for subsequent quarters are not expected to be material.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY The changes in total stockholders’ equity were as follows (in thousands): Total stockholders’ equity Balance at December 31, 2017 $ 786,333 Net loss (29,892 ) Exercise of stock options 54,621 Purchases under the employee stock purchase plan 12,578 Vesting of early exercised stock options and other 126 Issuance of common stock in connection with business combination 139,396 Replacement stock awards issued in connection with acquisition 757 Conversion feature of convertible senior notes, due 2023, net of allocated costs 154,019 Purchase of bond hedges in conjunction with issuance of convertible senior notes, due 2023 (172,586 ) Sale of warrants in conjunction with issuance of convertible senior notes, due 2023 112,125 Share-based compensation 103,196 Tax withholding related to vesting of restricted stock units (68,575 ) Cumulative adjustment for adoption of ASC 606 (4,586 ) Recovery of common stock in connection with indemnification settlement agreement (2,745 ) Change in other comprehensive loss (3,138 ) Balance at June 30, 2018 $ 1,081,629 Common Stock The Company has authorized the issuance of Class A common stock and Class B common stock. Class A common stock and Class B common stock are referred to as "common stock" throughout these Notes to the Condensed Consolidated Financial Statements, unless otherwise noted. As of June 30, 2018 , the Company was authorized to issue 1,000,000,000 shares of Class A common stock and 500,000,000 shares of Class B common stock, each with a par value of $0.0000001 per share. As of June 30, 2018 , there were 297,371,047 shares of Class A common stock and 109,580,981 shares of Class B common stock outstanding. Options and awards granted following the Company's initial public offering are related to underlying Class A common stock. Additionally, holders of Class B common stock are able to convert such shares into Class A common stock. Warrants In conjunction with the 2023 Notes offering, the Company sold the 2023 warrants whereby the counterparties have the option to purchase a total of approximately 11.1 million shares of the Company’s Class A common stock at a price of $109.26 per share. The Company received $112.1 million in cash proceeds from the sale of the 2023 warrants. See Note 12 , Indebtedness , for more details on this transaction. Release of Caviar Shares Held Back In 2014, in conjunction with the Company's acquisition of Caviar, Inc. (Caviar), 1,291,979 shares of the purchase consideration issuable were withheld for indemnification purposes. In April 2018, the Company reached an agreement with the former owners of Caviar whereby 822,085 of the shares held back were released to the former owners and 469,894 shares were forfeited back to the Company as indemnification against liabilities related to Caviar preacquisition matters. Upon reaching the agreement, the Company recorded an indemnification asset of $2.8 million and a corresponding credit to expense to compensate for the costs previously incurred in connection with Caviar preacquisition claims. The remaining value of the forfeited shares was treated as an equity repurchase. Stock Plans The Company maintains two share-based employee compensation plans: the 2009 Stock Plan (2009 Plan) and the 2015 Equity Incentive Plan (2015 Plan). The 2015 Plan serves as the successor to the 2009 Plan. The 2015 Plan became effective as of November 17, 2015. Outstanding awards under the 2009 Plan continue to be subject to the terms and conditions of the 2009 Plan. Since November 17, 2015, no additional awards have been nor will be in the future granted under the 2009 Plan. Under the 2015 Plan, shares of the Company's Class A common stock are reserved for the issuance of incentive and nonstatutory stock options, restricted stock awards (RSAs), restricted stock units (RSUs), performance shares, and stock bonuses to qualified employees, directors, and consultants. The awards must be granted at a price per share not less than the fair market value at the date of grant. Initially, 30,000,000 shares were reserved under the 2015 Plan, and any shares subject to options or other similar awards granted under the 2009 Plan that expire, are forfeited, are repurchased by the Company, or otherwise terminate unexercised, will become available under the 2015 Plan. The number of shares available for issuance under the 2015 Plan will be increased on the first day of each fiscal year, in an amount equal to the least of (i) 40,000,000 shares, (ii) 5% of the outstanding shares on the last day of the immediately preceding fiscal year, or (iii) such number of shares determined by the Company’s board of directors or a committee thereof. As of June 30, 2018 , the total number of shares subject to stock options, RSAs and RSUs outstanding under the 2015 Plan was 26,273,466 , and 63,326,561 shares were available for future issuance. As of June 30, 2018 , the total number of shares subject to stock options, RSAs and RSUs outstanding under the 2009 Plan was 34,740,852 . A summary of stock option activity for the six months ended June 30, 2018 is as follows (in thousands, except share and per share data): Number of Stock Options Outstanding Weighted Weighted Aggregate Balance at December 31, 2017 47,270,091 $ 8.67 6.52 $ 1,229,103 Granted 783,625 44.75 Exercised (7,460,458 ) 7.32 Forfeited (454,154 ) 12.21 Balance at June 30, 2018 40,139,104 $ 9.58 6.21 $ 2,089,523 Options exercisable as of June 30, 2018 37,006,235 $ 8.62 6.02 $ 1,962,153 Restricted Stock Activity Activity related to RSAs and RSUs during the six months ended June 30, 2018 is set forth below: Number of Weighted Unvested as of December 31, 2017 21,317,525 $ 17.84 Granted 4,439,906 45.62 Vested (3,736,968 ) 16.52 Forfeited (1,145,249 ) 17.00 Unvested as of June 30, 2018 20,875,214 $ 24.03 Share-Based Compensation The fair value of stock options and employee stock purchase plan rights are estimated on the date of grant using the Black-Scholes-Merton option valuation model. The fair value of RSAs and RSUs is determined by the closing price of the Company’s common stock on each grant date. The fair value of stock options granted was estimated using the following weighted-average assumptions: Three and Six Months Ended June 30, 2018 2017 Dividend yield — % — % Risk-free interest rate 2.92 % 1.88 % Expected volatility 30.87 % 32.22 % Expected term (years) 6.19 6.02 The following table summarizes the effects of share-based compensation on the Company's condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Cost of revenue $ 30 $ 18 $ 61 $ 18 Product development 33,806 25,136 64,288 44,492 Sales and marketing 5,634 4,355 10,595 8,290 General and administrative 12,649 10,084 23,999 18,463 Total $ 52,119 $ 39,593 $ 98,943 $ 71,263 The Company recorded $2.0 million and $4.2 million of share-based compensation expense related to the Company's 2015 Employee Stock Purchase Plan during the three and six months ended June 30, 2018 , respectively, compared to $1.2 million and $3.0 million for the three and six months ended June 30, 2017 , respectively, which are included in the table above. The Company capitalized $2.7 million and $4.3 million of share-based compensation expense related to capitalized software costs during the three and six months ended June 30, 2018 , respectively, compared to $0.7 million and $1.2 million for the three and six months ended June 30, 2017 , respectively. As of June 30, 2018 , there was $531.5 million of total unrecognized compensation cost related to outstanding awards that are expected to be recognized over a weighted-average period of 2.87 years .

LOSS PER SHARE

LOSS PER SHARE	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
LOSS PER SHARE	LOSS PER SHARE Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted loss per share is the same as basic loss per share for all periods presented because the effects of potentially dilutive items were anti-dilutive given the Company’s net loss. The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Net loss $ (5,906 ) $ (15,962 ) $ (29,892 ) $ (31,052 ) Basic shares: Weighted-average common shares outstanding 403,390 377,959 400,318 373,291 Weighted-average unvested shares (89 ) (1,602 ) (694 ) (1,718 ) Weighted-average shares used to compute basic net loss per share 403,301 376,357 399,624 371,573 Diluted shares: Weighted-average shares used to compute diluted loss per share 403,301 376,357 399,624 371,573 Net loss per share: Basic $ (0.01 ) $ (0.04 ) $ (0.07 ) $ (0.08 ) Diluted $ (0.01 ) $ (0.04 ) $ (0.07 ) $ (0.08 ) Additionally, since the Company expects to settle the principal amount of its outstanding 2022 Notes and 2023 Notes in cash, the Company uses the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread will have a dilutive impact on diluted net income per share of common stock when the average market price of the Company’s common stock for a given period exceeds the conversion price of $ 22.95 per share, for the 2022 Notes, or $77.85 , for the 2023 Notes. Because the Company has reported a net loss for all periods presented, diluted loss per share is the same as basic loss per share for those periods. The following potential common shares were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Stock options and restricted stock units 62,908 81,919 64,635 83,406 Common stock warrants 23,605 19,173 21,377 15,173 Unvested shares 89 1,602 694 1,718 Employee stock purchase plan 170 340 189 359 Total anti-dilutive securities 86,772 103,034 86,895 100,656

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Operating and Capital Leases The Company has entered into various non-cancelable operating leases for certain offices with contractual lease periods expiring between 2018 and 2025 . The Company recognized total rental expenses under operating leases of $5.3 million and $9.8 million for the three and six months ended June 30, 2018 , respectively, compared to $3.1 million and $5.9 million for the three and six months ended June 30, 2017 , respectively. Future minimum lease payments under non-cancelable operating leases (with initial lease terms in excess of one year) and future minimum capital lease payments as of June 30, 2018 are as follows (in thousands): Capital Operating Year: 2018 (remaining 6 months) $ 2,599 $ 13,852 2019 5,089 32,823 2020 2,501 34,437 2021 46 34,473 2022 2 35,038 Thereafter — 34,037 Total $ 10,237 $ 184,660 Less amount representing interest (14 ) Present value of capital lease obligations 10,223 Less current portion of capital lease obligation (5,190 ) Non-current portion of capital lease obligation $ 5,033 Litigation The Company is currently a party to, and may in the future be involved in, various litigation matters (including intellectual property litigation), legal claims, and government investigations. The Treasurer & Tax Collector of the City and County of San Francisco (Tax Collector) has issued a decision for fiscal years 2014 and 2015, that the Tax Collector believes the Company’s primary business activity is financial services rather than information services, and accordingly, the Company would be liable for the Gross Receipts Tax and Payroll Expense Tax under the rules for financial services business activities. The Company paid the liability for fiscal years 2014 and 2015 in the first quarter of 2018, as assessed by the Tax Collector. The Company intends to vigorously defend its position, which it believes has merit. Should the Company not prevail, the Company could be obligated to pay additional taxes together with any associated penalties and interest for subsequent years that together, in aggregate, could be material. The Company is currently unable to estimate the range of possible loss given the uncertainties associated with this matter, including uncertainties about the Tax Collector’s rationale for its position and about the amounts that may ultimately be subject to such taxes. In addition, from time to time, the Company is involved in various other litigation matters and disputes arising in the ordinary course of business. The Company cannot at this time fairly estimate a reasonable range of exposure, if any, of the potential liability with respect to these other matters. While the Company does not believe, at this time, that any ultimate liability resulting from any of these other matters will have a material adverse effect on the Company's results of operations, financial position, or liquidity, the Company cannot give any assurance regarding the ultimate outcome of these other matters, and their resolution could be material to the Company's operating results for any particular period.

SEGMENT AND GEOGRAPHICAL INFORM

SEGMENT AND GEOGRAPHICAL INFORMATION	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
SEGMENT AND GEOGRAPHIC INFORMATION	SEGMENT AND GEOGRAPHICAL INFORMATION Operating segments are defined as components of an enterprise for which discrete financial information is available that is evaluated regularly by the chief operating decision maker (CODM) for purposes of allocating resources and evaluating financial performance. The Company’s CODM is the chief executive officer who reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. As such, the Company’s operations constitute a single operating segment and one reportable segment. Revenue Revenue by geography is based on the billing addresses of the sellers or customers. The following table sets forth revenue by geographic area (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Revenue United States $ 777,335 $ 530,008 $ 1,417,508 $ 974,907 International 37,603 21,497 66,033 38,152 Total net revenue $ 814,938 $ 551,505 $ 1,483,541 $ 1,013,059 No individual country from the international markets contributed in excess of 10% of total revenue for the three and six months ended June 30, 2018 and 2017 . Long-Lived Assets The following table sets forth long-lived assets by geographic area (in thousands): June 30, December 31, Long-lived assets United States $ 456,159 $ 158,820 International 6,757 5,337 Total long-lived assets $ 462,916 $ 164,157

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	6 Months Ended
	Jun. 30, 2018
Supplemental Cash Flow Elements [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION The supplemental disclosures of cash flow information consist of the following (in thousands): Six Months Ended June 30, 2018 2017 Supplemental Cash Flow Data: Cash paid for interest $ 1,108 $ 284 Cash paid for income taxes 854 850 Supplemental disclosures of non-cash investing and financing activities: Change in purchases of property and equipment in accounts payable and accrued expenses 9,708 1,454 Unpaid business acquisition purchase price 3,995 644 Fair value of common stock issued related to business combination (139,396 ) — Recovery of common stock in connection with indemnification settlement agreement 2,745 —

DESCRIPTION OF BUSINESS AND S26

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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, 2017 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 loss, and cash flows for the interim periods. All intercompany transactions and balances have been eliminated in consolidation. The interim results for the three and six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 , 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 “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Quantitative and Qualitative Disclosures About Market Risk,” and the Consolidated Financial Statements and notes thereto included in Items 7, 7A, and 8, respectively, in the Company's Annual Report on Form 10-K for the year ended December 31, 2017 .
Use of Estimates	The preparation of the Company’s 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 past experience and other assumptions that the Company believes are reasonable under the circumstances, and the Company evaluates these estimates on an ongoing basis. Estimates, judgments, and assumptions in these consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, valuation of the debt component of convertible senior notes, valuation of loans held for sale, goodwill, acquired intangible assets and deferred revenue, income and other taxes, and share-based compensation.
Concentration of Credit Risk	For the three and six months ended June 30, 2018 and 2017 , the Company had no customer that accounted for greater than 10% of total net revenue. The Company had three third-party payment processors that represented approximately 46% , 43% , and 7% of settlements receivable as of June 30, 2018 . The same three parties represented approximately 46% , 42% , and 8% of settlements receivable as of December 31, 2017 . 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 securities, settlements receivables, customer funds, 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 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 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.
Cryptocurrency transactions	During the fourth quarter of 2017, the Company started offering its Cash App customers the ability to purchase bitcoin, a cryptocurrency denominated asset, from the Company. The Company purchases bitcoin from private broker dealers or from customers. Upon purchase, the Company records the cost of bitcoin within other current assets in its consolidated balance sheets. Upon sale, the Company records the total sale amount received from customers as bitcoin revenue and the associated cost as cost of revenue. The carrying value of bitcoin held by the Company was $0.4 million and $0.3 million as of June 30, 2018 and December 31, 2017 , respectively. The Company assesses the carrying value of bitcoin held by the Company at each reporting date and records an impairment charge if the cost exceeds the fair value. Losses on bitcoin for the three and six months ended June 30, 2018 , were insignificant.
Recent Accounting Pronouncements	Recently issued accounting pronouncements not yet adopted In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases , which will require, among other items, lessees to recognize a right of use asset and a related lease liability for most leases on the balance sheet. Qualitative and quantitative disclosures will be enhanced to better understand the amount, timing and uncertainty of cash flows arising from leases. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The new standard should be applied on a modified retrospective basis. The Company does not plan to early adopt this guidance. The Company’s operating leases primarily comprise of office spaces, with the most significant leases relating to corporate headquarters in San Francisco and an office in New York. While the Company continues to evaluate the impact of adopting this guidance on its consolidated financial statements, it does expect to record material right to use assets and related lease liabilities on its consolidated balance sheets upon adoption, which will increase total assets and liabilities. In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments , which requires measurement and recognition of expected credit losses for financial assets held. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact this new guidance may have on the consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment . The new guidance eliminates the requirement to calculate the implied fair value of goodwill assuming a hypothetical purchase price allocation (i.e., Step 2 of the goodwill impairment test) to measure a goodwill impairment charge. Instead, entities will record an impairment charge based on the excess of a reporting unit’s carrying amount over its fair value, not to exceed the carrying amount of goodwill. This standard should be adopted when the Company performs its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted. The amendments should be applied on a prospective basis. The Company does not expect the adoption of this guidance to have a material the impact on the consolidated financial statements and related disclosures. In March 2017, the FASB issued ASU No. 2017-08, Premium Amortization on Purchased Callable Debt Securities, which amends the amortization period for certain purchased callable debt securities held at a premium, shortening such period to the earliest call date. This standard is effective for annual periods beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The amendments in this guidance should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The Company is currently evaluating the impact this new guidance may have on the consolidated financial statements and related disclosures. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . When the Tax Cuts and Jobs Act of 2017 was enacted in December 2017, there was a valuation allowance on the deferred tax assets included within the Company's accumulated other comprehensive income; therefore no tax expense resulted from the change in the federal income tax rate. This guidance allows companies to reclassify such tax effects from accumulated other comprehensive income to retained earnings. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures. In February 2018, the FASB issued ASU 2018-03, Recognition and Measurement of Financial Assets and Financial Liabilities. This guidance clarifies that an entity that uses the measurement alternative for equity securities without readily determinable fair values can change its measurement approach to fair value. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years beginning after June 15, 2018. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures.

REVENUE (Tables)

REVENUE (Tables)	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Impact of Adoption of ASC 606	The impact of adoption of ASC 606 on the Company's condensed consolidated statement of operations was as follows (in thousands): Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 As reported Balances without adoption Effect of change As reported Balances without adoption Effect of change Impact on the Condensed Consolidated Statement of Operations: Subscription and services-based revenue $ 134,332 $ 134,240 $ 92 $ 231,386 $ 231,235 $ 151 Hardware revenue 18,362 16,079 2,283 32,779 29,233 3,546 Subscription and services-based costs 39,784 39,784 — 70,152 70,152 — Hardware costs $ 25,536 $ 22,939 $ 2,597 $ 45,238 $ 41,696 $ 3,542 The impact of adoption of ASC 606 on the Company's condensed consolidated balance sheets was as follows (in thousands): June 30, 2018 As reported Balances without adoption Effect of change Impact on the Condensed Consolidated Balance Sheets: Other current assets $ 120,250 $ 131,464 $ (11,214 ) Other current liabilities 60,635 67,486 (6,851 ) Other non-current assets 40,995 42,570 (1,575 ) Other non-current liabilities $ 85,851 $ 87,282 $ (1,431 )
Schedule of Disaggregation of Revenue	The following table presents the Company's revenue from contracts with customers disaggregated by revenue source (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Revenue from Contracts with Customers: Transaction-based revenue $ 625,228 $ 482,065 $ 1,148,265 $ 885,543 Subscription and services-based revenue 111,670 59,151 188,885 108,211 Hardware revenue $ 18,362 $ 10,289 $ 32,779 $ 19,305 Bitcoin revenue $ 37,016 $ — $ 71,111 $ —
Schedule of Deferred Revenue	The deferred revenue balances were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Deferred revenue, beginning of the period $ 3,353 $ 2,965 $ 5,893 $ 5,407 Less: accumulative adjustment for adoption of ASC 606 — — (4,303 ) — Deferred revenue, beginning of the period, as adjusted 3,353 2,965 1,590 5,407 Deferred revenue, end of the period 27,155 4,523 27,155 4,523 Deferred revenue arising from business combination 22,800 — 22,800 — Revenue recognized in the period from amounts included in deferred revenue at the beginning of the period 1,975 925 1,095 5,257

FAIR VALUE OF FINANCIAL INSTR28

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The estimated fair value and carrying value of the convertible senior notes were as follows (in thousands): June 30, 2018 December 31, 2017 Carrying Value Fair Value (Level 2) Carrying Value Fair Value (Level 2) 2023 Notes $ 704,021 $ 924,936 $ — $ — 2022 Notes 367,416 1,188,686 358,572 719,356 Total $ 1,071,437 $ 2,113,622 $ 358,572 $ 719,356 The Company’s financial assets and liabilities that are measured at fair value on a recurring basis are classified as follows (in thousands): June 30, 2018 December 31, 2017 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash and Cash Equivalents: Money market funds $ 1,031,129 $ — $ — $ 387,698 $ — $ — U.S. agency securities — 35,086 — — — — Commercial paper — — — — 24,695 — U.S. government securities 34,978 — — — — — Short-term securities: U.S. agency securities — 14,997 — — 15,083 — Corporate bonds — 57,371 — — 57,798 — Commercial paper — — — — 17,428 — Municipal securities — 23,740 — — 23,700 — U.S. government securities 137,491 — — 55,567 — — Long-term securities: U.S. agency securities — 10,076 — — 20,169 — Corporate bonds — 52,567 — — 91,413 — Municipal securities — 19,444 — — 26,224 — U.S. government securities 86,063 — — 65,861 — — Total $ 1,289,661 $ 213,281 $ — $ 509,126 $ 276,510 $ — A summary of loans disclosed at fair value on a recurring basis is as follows (in thousands): June 30, 2018 December 31, 2017 Carrying Value Fair Value (Level 3) Carrying Value Fair Value (Level 3) Loans held for sale $ 85,040 $ 88,645 $ 73,420 $ 76,070 Total $ 85,040 $ 88,645 $ 73,420 $ 76,070

INVESTMENTS (Tables)

INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Short-term and Long-term Investments	The Company's short-term and long-term investments as of June 30, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term securities: U.S. agency securities $ 14,978 $ 19 $ — $ 14,997 Corporate bonds 57,293 201 (123 ) 57,371 Commercial paper — — — — Municipal securities 23,720 30 (10 ) 23,740 U.S. government securities 137,499 78 (86 ) 137,491 Total $ 233,490 $ 328 $ (219 ) $ 233,599 Long-term securities: U.S. agency securities $ 10,096 $ — $ (20 ) $ 10,076 Corporate bonds 52,354 245 (32 ) 52,567 Municipal securities 19,483 10 (49 ) 19,444 U.S. government securities 86,086 88 (111 ) 86,063 Total $ 168,019 $ 343 $ (212 ) $ 168,150 The Company's short-term and long-term investments as of December 31, 2017 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term securities: U.S. agency securities $ 15,122 $ — $ (39 ) $ 15,083 Corporate bonds 57,855 22 (79 ) 57,798 Commercial paper 17,428 — — 17,428 Municipal securities 23,743 8 (51 ) 23,700 U.S. government securities 55,729 1 (163 ) 55,567 Total $ 169,877 $ 31 $ (332 ) $ 169,576 Long-term securities: U.S. agency securities $ 20,288 $ 2 $ (121 ) $ 20,169 Corporate bonds 91,959 25 (571 ) 91,413 Municipal securities 26,371 13 (160 ) 26,224 U.S. government securities 66,362 19 (520 ) 65,861 Total $ 204,980 $ 59 $ (1,372 ) $ 203,667
Investments Classified by Contractual Maturity Date	The contractual maturities of the Company's short-term and long-term investments as of June 30, 2018 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 233,490 $ 233,599 Due in one to five years 168,019 168,150 Total $ 401,509 $ 401,749

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	6 Months Ended
	Jun. 30, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	The following is a summary of property and equipment, less accumulated depreciation and amortization (in thousands): June 30, December 31, Leasehold improvements $ 94,241 $ 77,073 Computer equipment 81,763 66,186 Capitalized software 45,927 35,063 Office furniture and equipment 18,231 14,490 240,162 192,812 Less: Accumulated depreciation and amortization (118,454 ) (101,316 ) Property and equipment, net $ 121,708 $ 91,496

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Schedule of Assets Acquired and Liabilities Assumed	The table below summarizes the consideration paid for Weebly and the preliminary assessment of the fair value of the assets acquired and liabilities assumed at the closing date (in thousands, except share data). The Company is in the process of completing the valuation of the acquired intangible assets and deferred revenue and is evaluating contingencies and tax effects related to the acquisition. Accordingly, the preliminary values reflected in the table are subject to change. Consideration: Cash $ 131,860 Stock (2,406,071 shares of common stock) 139,396 $ 271,256 Recognized amounts of identifiable assets acquired and liabilities assumed: Current assets (inclusive of cash acquired of $25,758) $ 44,685 Intangible customer assets 42,700 Intangible technology assets 14,900 Intangible trade name 11,300 Intangible other assets 961 Total liabilities assumed (including deferred revenue of $22,800) (32,824 ) Total identifiable net assets acquired 81,722 Goodwill 189,534 Total $ 271,256

GOODWILL (Tables)

GOODWILL (Tables)	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The change in carrying value of goodwill in the period was as follows (in thousands): Balance at December 31, 2017 $ 58,327 Acquisitions completed during the six months ended June 30, 2018 197,329 Balance at June 30, 2018 $ 255,656

ACQUIRED INTANGIBLE ASSETS (Tab

ACQUIRED INTANGIBLE ASSETS (Tables)	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite Lived Intangible Assets	The changes to the carrying value of intangible assets were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Acquired intangible assets, net, beginning of the period $ 14,138 $ 18,395 $ 14,334 $ 19,292 Acquisitions 74,192 — 75,871 1,224 Amortization expense 2,816 1,943 4,691 4,064 Acquired intangible assets, net, end of the period $ 85,514 $ 16,452 $ 85,514 $ 16,452 The following table presents the detail of acquired intangible assets as of the periods presented (in thousands): Balance at June 30, 2018 Cost Accumulated Amortization Net Patents $ 1,285 $ (611 ) $ 674 Technology assets 45,978 (24,766 ) 21,212 Customer assets 57,109 (5,481 ) 51,628 Trade name 11,300 (235 ) 11,065 Other 961 (26 ) 935 Total $ 116,633 $ (31,119 ) $ 85,514 Balance at December 31, 2017 Cost Accumulated Amortization Net Patents $ 1,285 $ (559 ) $ 726 Technology assets 29,158 (21,329 ) 7,829 Customer assets 10,319 (4,540 ) 5,779 Total $ 40,762 $ (26,428 ) $ 14,334
Schedule of Annual Future Amortization Expense of Intangible Assets	The total estimated future amortization expense of these intangible assets as of June 30, 2018 is as follows (in thousands): 2018 (remaining 6 months) $ 7,863 2019 13,843 2020 11,638 2021 10,440 2022 8,511 Thereafter 33,219 Total $ 85,514

OTHER CONSOLIDATED BALANCE SH34

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) (Tables)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Other Current Assets	The following table presents the detail of other current assets (in thousands): June 30, December 31, Inventory, net $ 22,041 $ 16,777 Processing costs receivable 33,861 21,083 Prepaid expenses 16,663 14,473 Accounts receivable, net 17,895 8,606 Deferred hardware costs (i) — 7,931 Deferred magstripe reader costs (ii) 3,034 2,469 Prepaid compensation, current (iii) 5,940 — Other 20,816 15,115 Total $ 120,250 $ 86,454 (i) The deferred hardware costs represented costs associated with hardware sold through the retail distribution channels. The adoption of ASC 606 on January 1, 2018, has resulted in the recognition of such costs upon delivery of the hardware to the distribution channel. (ii) The Company capitalizes the cost of its magstripe readers, including packaging and shipping costs, held on-hand by the Company as of each consolidated balance sheet date. Once the readers are shipped to a third-party distributor or an end-customer, they are recorded as marketing expense on the consolidated statements of operations. (iii) Prepaid compensation relates to cash transferred by the Company to an escrow agent in connection with a business combination that will be paid to officers of the acquiree over time as they provide services to the Company.
Schedule of Accrued Expenses	The following table presents the detail of accrued expenses (in thousands): June 30, December 31, Accrued payroll $ 10,229 $ 9,103 Accrued professional fees 9,168 5,638 Accrued advertising and other marketing 11,961 6,723 Processing costs payable 11,205 10,145 Accrued non income tax liabilities 7,504 6,155 Accrued hardware costs 1,806 2,496 Other accrued liabilities 22,943 12,020 Total $ 74,816 $ 52,280
Schedule of Other Current Liabilities	The following table presents the detail of other current liabilities (in thousands): June 30, December 31, Square Capital payable (iv) $ 10,301 $ 7,671 Square Payroll payable (v) 6,494 2,850 Deferred revenue, current 24,062 5,893 Deferred rent, current 3,691 3,311 Accrued redemptions 1,110 1,036 Other 14,977 7,606 Total $ 60,635 $ 28,367 (iv) Square Capital payable represents unpaid amounts arising from the purchase of loans or loan repayments collected on behalf of third parties. (v) Square Payroll payable represents amounts received from Square Payroll product customers that will be utilized to settle the customers employee payroll and related obligations.

OTHER CONSOLIDATED BALANCE SH35

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) (Tables)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Other Non-Current Assets	The following table presents the detail of other non-current assets (in thousands): June 30, December 31, Investment in privately held entity $ 25,000 $ 25,000 Prepaid compensation, non-current (i) 7,927 — Deposits 2,646 2,738 Debt issuance costs 650 788 Deferred tax assets 680 519 Other 4,092 2,305 Total $ 40,995 $ 31,350 (i) Prepaid compensation relates to cash transferred by the Company to an escrow agent in connection with a business combination that will be paid to officers of the acquiree over time as they provide services to the Company.
Schedule of Other Non-Current Liabilities	The following table presents the detail of other non-current liabilities (in thousands): June 30, December 31, Statutory liabilities (ii) $ 47,423 $ 40,768 Deferred rent, non-current 21,479 20,349 Deferred purchase consideration 3,900 — Deferred revenue, non-current 3,093 432 Deferred tax liabilities 148 644 Other 9,808 7,345 Total $ 85,851 $ 69,538 (ii) Statutory liabilities represent loss contingencies that may arise from the Company's interpretation and application of certain guidelines and rules issued by various federal, state, local, and foreign regulatory authorities.

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Convertible Notes	The net carrying amount of the Notes were as follows (in thousands): Principal outstanding Unamortized debt discount Unamortized debt issuance costs Net carrying value June 30, 2018 2023 Notes 862,500 (152,955 ) (5,524 ) 704,021 2022 Notes 440,000 (65,414 ) (7,170 ) 367,416 Total 1,302,500 (218,369 ) (12,694 ) 1,071,437 December 31, 2017 2022 Notes 440,000 (73,384 ) (8,044 ) 358,572 The net carrying amount of the equity component of the Notes were as follows (in thousands): Amount allocated to conversion option Less: allocated issuance costs Equity component, net June 30, 2018 2023 Notes 155,250 (1,231 ) 154,019 2022 Notes 86,203 (2,302 ) 83,901 Total 241,453 (3,533 ) 237,920 December 31, 2017 2022 Notes 86,203 (2,302 ) 83,901
Interest Expense on Convertible Notes	The Company recognized interest expense on the Notes as follows (in thousands, except for percentages): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Contractual interest expense $ 850 $ 413 $ 1,263 $ 526 Amortization of debt discount and issuance costs 6,830 4,221 11,223 5,611 Total $ 7,680 $ 4,634 $ 12,486 $ 6,137

ACCRUED TRANSACTION LOSSES (Tab

ACCRUED TRANSACTION LOSSES (Tables)	6 Months Ended
	Jun. 30, 2018
Product Warranties Disclosures [Abstract]
Schedule of Reserve for Transaction Losses	The following table summarizes the activities of the Company’s reserve for transaction losses (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Accrued transaction losses, beginning of the period $ 28,309 $ 20,444 $ 26,893 $ 20,064 Provision for transaction losses 14,087 13,076 28,345 24,634 Charge-offs to accrued transaction losses (13,189 ) (11,065 ) (26,031 ) (22,243 ) Accrued transaction losses, end of the period $ 29,207 $ 22,455 $ 29,207 $ 22,455

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Changes in Stockholder's Equity	The changes in total stockholders’ equity were as follows (in thousands): Total stockholders’ equity Balance at December 31, 2017 $ 786,333 Net loss (29,892 ) Exercise of stock options 54,621 Purchases under the employee stock purchase plan 12,578 Vesting of early exercised stock options and other 126 Issuance of common stock in connection with business combination 139,396 Replacement stock awards issued in connection with acquisition 757 Conversion feature of convertible senior notes, due 2023, net of allocated costs 154,019 Purchase of bond hedges in conjunction with issuance of convertible senior notes, due 2023 (172,586 ) Sale of warrants in conjunction with issuance of convertible senior notes, due 2023 112,125 Share-based compensation 103,196 Tax withholding related to vesting of restricted stock units (68,575 ) Cumulative adjustment for adoption of ASC 606 (4,586 ) Recovery of common stock in connection with indemnification settlement agreement (2,745 ) Change in other comprehensive loss (3,138 ) Balance at June 30, 2018 $ 1,081,629
Summary of Stock Option Activity	A summary of stock option activity for the six months ended June 30, 2018 is as follows (in thousands, except share and per share data): Number of Stock Options Outstanding Weighted Weighted Aggregate Balance at December 31, 2017 47,270,091 $ 8.67 6.52 $ 1,229,103 Granted 783,625 44.75 Exercised (7,460,458 ) 7.32 Forfeited (454,154 ) 12.21 Balance at June 30, 2018 40,139,104 $ 9.58 6.21 $ 2,089,523 Options exercisable as of June 30, 2018 37,006,235 $ 8.62 6.02 $ 1,962,153
Schedule of RSU Activity	Activity related to RSAs and RSUs during the six months ended June 30, 2018 is set forth below: Number of Weighted Unvested as of December 31, 2017 21,317,525 $ 17.84 Granted 4,439,906 45.62 Vested (3,736,968 ) 16.52 Forfeited (1,145,249 ) 17.00 Unvested as of June 30, 2018 20,875,214 $ 24.03
Schedule of Fair Value Assumptions for Options	The fair value of stock options granted was estimated using the following weighted-average assumptions: Three and Six Months Ended June 30, 2018 2017 Dividend yield — % — % Risk-free interest rate 2.92 % 1.88 % Expected volatility 30.87 % 32.22 % Expected term (years) 6.19 6.02
Summary of the Effect of Share-Based Compensation on the Condensed Consolidated Statements of Operations	The following table summarizes the effects of share-based compensation on the Company's condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Cost of revenue $ 30 $ 18 $ 61 $ 18 Product development 33,806 25,136 64,288 44,492 Sales and marketing 5,634 4,355 10,595 8,290 General and administrative 12,649 10,084 23,999 18,463 Total $ 52,119 $ 39,593 $ 98,943 $ 71,263

LOSS PER SHARE (Tables)

LOSS PER SHARE (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Net loss $ (5,906 ) $ (15,962 ) $ (29,892 ) $ (31,052 ) Basic shares: Weighted-average common shares outstanding 403,390 377,959 400,318 373,291 Weighted-average unvested shares (89 ) (1,602 ) (694 ) (1,718 ) Weighted-average shares used to compute basic net loss per share 403,301 376,357 399,624 371,573 Diluted shares: Weighted-average shares used to compute diluted loss per share 403,301 376,357 399,624 371,573 Net loss per share: Basic $ (0.01 ) $ (0.04 ) $ (0.07 ) $ (0.08 ) Diluted $ (0.01 ) $ (0.04 ) $ (0.07 ) $ (0.08 )
Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	The following potential common shares were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Stock options and restricted stock units 62,908 81,919 64,635 83,406 Common stock warrants 23,605 19,173 21,377 15,173 Unvested shares 89 1,602 694 1,718 Employee stock purchase plan 170 340 189 359 Total anti-dilutive securities 86,772 103,034 86,895 100,656

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Payments Under Operating and Capital Leases	Future minimum lease payments under non-cancelable operating leases (with initial lease terms in excess of one year) and future minimum capital lease payments as of June 30, 2018 are as follows (in thousands): Capital Operating Year: 2018 (remaining 6 months) $ 2,599 $ 13,852 2019 5,089 32,823 2020 2,501 34,437 2021 46 34,473 2022 2 35,038 Thereafter — 34,037 Total $ 10,237 $ 184,660 Less amount representing interest (14 ) Present value of capital lease obligations 10,223 Less current portion of capital lease obligation (5,190 ) Non-current portion of capital lease obligation $ 5,033

SEGMENT AND GEOGRAPHICAL INFO41

SEGMENT AND GEOGRAPHICAL INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Revenue from External Customers by Geographic Areas	Revenue by geography is based on the billing addresses of the sellers or customers. The following table sets forth revenue by geographic area (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Revenue United States $ 777,335 $ 530,008 $ 1,417,508 $ 974,907 International 37,603 21,497 66,033 38,152 Total net revenue $ 814,938 $ 551,505 $ 1,483,541 $ 1,013,059
Long-lived Assets by Geographic Areas	The following table sets forth long-lived assets by geographic area (in thousands): June 30, December 31, Long-lived assets United States $ 456,159 $ 158,820 International 6,757 5,337 Total long-lived assets $ 462,916 $ 164,157

SUPPLEMENTAL CASH FLOW INFORM42

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2018
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	The supplemental disclosures of cash flow information consist of the following (in thousands): Six Months Ended June 30, 2018 2017 Supplemental Cash Flow Data: Cash paid for interest $ 1,108 $ 284 Cash paid for income taxes 854 850 Supplemental disclosures of non-cash investing and financing activities: Change in purchases of property and equipment in accounts payable and accrued expenses 9,708 1,454 Unpaid business acquisition purchase price 3,995 644 Fair value of common stock issued related to business combination (139,396 ) — Recovery of common stock in connection with indemnification settlement agreement 2,745 —

DESCRIPTION OF BUSINESS AND S43

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018USD ($)customer	Jun. 30, 2017customer	Jun. 30, 2018USD ($)customerthird_party_processor	Jun. 30, 2017customer	Dec. 31, 2017USD ($)third_party_processor
Concentration Risk [Line Items]
Cryptocurrency denominated assets | $	$ 0.4		$ 0.4		$ 0.3
Total Net Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers | customer	0	0	0	0
Settlements Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Number of third party processors | third_party_processor			3		3
Settlements Receivable | Credit Concentration Risk | Third Party Processor One
Concentration Risk [Line Items]
Concentration risk, percentage			46.00%		46.00%
Settlements Receivable | Credit Concentration Risk | Third Party Processor Two
Concentration Risk [Line Items]
Concentration risk, percentage			43.00%		42.00%
Settlements Receivable | Credit Concentration Risk | Third Party Processor Three
Concentration Risk [Line Items]
Concentration risk, percentage			7.00%		8.00%
Minimum
Concentration Risk [Line Items]
Settlements receivable period			1 day
Maximum
Concentration Risk [Line Items]
Settlements receivable period			2 days

REVENUE - Narrative (Details)

REVENUE - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Retained earnings (accumulated deficit)	$ (877,213)		$ (877,213)			$ (842,735)
Revenue	792,300		1,441,000
Revenue, other	22,700		42,500
Impairment losses arising from contracts with customers	900		1,800
Effect of change | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Retained earnings (accumulated deficit)					$ (4,600)
Revenue	2,400		$ 3,700
Minimum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Distributors and retailers, payment terms			30 days
Customer installment sales, terms			3 months
Term of revenue recognition for website hosting			1 month
Term of revenue recognition for domain name registration			1 year
Maximum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Distributors and retailers, payment terms			90 days
Customer installment sales, terms			24 months
Term of revenue recognition for website hosting			24 months
Term of revenue recognition for domain name registration			10 years
Bitcoin revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 37,016	$ 0	$ 71,111	$ 0

REVENUE - Adoption of ASC 606 o

REVENUE - Adoption of ASC 606 on the Condensed Consolidated Statement of Operation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 814,938	$ 551,505	$ 1,483,541	$ 1,013,059
Subscription and services-based revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	134,332	59,151	231,386	108,211
Cost of revenue	39,784	17,116	70,152	32,992
Subscription and services-based revenue | Balances without adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	134,240		231,235
Cost of revenue	39,784		70,152
Subscription and services-based revenue | ASU 2014-09 | Effect of change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	92		151
Cost of revenue	0		0
Hardware revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	18,362	10,289	32,779	19,305
Cost of revenue	25,536	$ 14,173	45,238	$ 26,835
Hardware revenue | Balances without adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	16,079		29,233
Cost of revenue	22,939		41,696
Hardware revenue | ASU 2014-09 | Effect of change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	2,283		3,546
Cost of revenue	$ 2,597		$ 3,542

REVENUE - Adoption of ASC 60646

REVENUE - Adoption of ASC 606 on the Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets	$ 120,250	$ 86,454
Other current liabilities	60,635	28,367
Other non-current assets	40,995	31,350
Other non-current liabilities	85,851	$ 69,538
Balances without adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets	131,464
Other current liabilities	67,486
Other non-current assets	42,570
Other non-current liabilities	87,282
ASU 2014-09 | Effect of change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets	(11,214)
Other current liabilities	(6,851)
Other non-current assets	(1,575)
Other non-current liabilities	$ (1,431)

REVENUE - Revenue from Contract

REVENUE - Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue, contracts from customers	$ 792,300		$ 1,441,000
Transaction-based revenue
Disaggregation of Revenue [Line Items]
Revenue, contracts from customers	625,228	$ 482,065	1,148,265	$ 885,543
Subscription and services-based revenue
Disaggregation of Revenue [Line Items]
Revenue, contracts from customers	111,670	59,151	188,885	108,211
Hardware revenue
Disaggregation of Revenue [Line Items]
Revenue, contracts from customers	18,362	10,289	32,779	19,305
Bitcoin revenue
Disaggregation of Revenue [Line Items]
Revenue, contracts from customers	$ 37,016	$ 0	$ 71,111	$ 0

REVENUE - Deferred Revenue (Det

REVENUE - Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred revenue, end of the period	$ 27,155	$ 4,523	$ 27,155	$ 4,523
Deferred revenue arising from business combination	22,800	0	22,800	0
Revenue recognized in the period from amounts included in deferred revenue at the beginning of the period	1,975	925	1,095	5,257
Balances without adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred revenue, beginning of the period	$ 3,353	$ 2,965	$ 5,893	$ 5,407

RESTRICTED CASH (Details)

RESTRICTED CASH (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Pledged cash	$ 27,487	$ 28,805
Collateral	12,908	$ 9,802
Weebly, Inc.
Restricted Cash and Cash Equivalents Items [Line Items]
Collateral	$ 3,100

FAIR VALUE OF FINANCIAL INSTR50

FAIR VALUE OF FINANCIAL INSTRUMENTS - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	$ 233,599	$ 169,576
Long-term securities	168,150	203,667
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	1,289,661	509,126
Fair Value, Measurements, Recurring | Level 1 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Fair Value, Measurements, Recurring | Level 1 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	137,491	55,567
Long-term securities	86,063	65,861
Fair Value, Measurements, Recurring | Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,031,129	387,698
Fair Value, Measurements, Recurring | Level 1 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	34,978	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	213,281	276,510
Fair Value, Measurements, Recurring | Level 2 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	14,997	15,083
Long-term securities	10,076	20,169
Fair Value, Measurements, Recurring | Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	57,371	57,798
Long-term securities	52,567	91,413
Fair Value, Measurements, Recurring | Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	17,428
Fair Value, Measurements, Recurring | Level 2 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	23,740	23,700
Long-term securities	19,444	26,224
Fair Value, Measurements, Recurring | Level 2 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 2 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	35,086	0
Fair Value, Measurements, Recurring | Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	24,695
Fair Value, Measurements, Recurring | Level 2 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	0	0
Long-term securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 0	$ 0

FAIR VALUE OF FINANCIAL INSTR51

FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value of Convertible Senior Notes (Details) - Level 2 - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2023 Notes	$ 1,071,437	$ 358,572
Fair Value (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2023 Notes	2,113,622	719,356
Convertible Senior Notes due in 2023 | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2023 Notes	704,021	0
Convertible Senior Notes due in 2023 | Fair Value (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2023 Notes	924,936	0
Convertible Senior Notes due in 2022 | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2023 Notes	367,416	358,572
Convertible Senior Notes due in 2022 | Fair Value (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2023 Notes	$ 1,188,686	$ 719,356

FAIR VALUE OF FINANCIAL INSTR52

FAIR VALUE OF FINANCIAL INSTRUMENTS - Loans Disclosed at Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Carrying Value | Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, fair value	$ 85,040		$ 85,040		$ 73,420
Fair Value (Level 3) | Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, fair value	88,645		88,645		$ 76,070
Loans Receivable Held-For-Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Excess amortized cost over fair value of loans charge	$ 3,200	$ (2,700)	$ 5,700	$ (2,700)

INVESTMENTS - Available for Sa

INVESTMENTS - Available for Sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Total	$ 401,509
Fair Value	401,749
Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	233,490	$ 169,877
Gross Unrealized Gains	328	31
Gross Unrealized Losses	(219)	(332)
Fair Value	233,599	169,576
Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	168,019	204,980
Gross Unrealized Gains	343	59
Gross Unrealized Losses	(212)	(1,372)
Fair Value	168,150	203,667
U.S. agency securities | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	14,978	15,122
Gross Unrealized Gains	19	0
Gross Unrealized Losses	0	(39)
Fair Value	14,997	15,083
U.S. agency securities | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	10,096	20,288
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(20)	(121)
Fair Value	10,076	20,169
Corporate bonds | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	57,293	57,855
Gross Unrealized Gains	201	22
Gross Unrealized Losses	(123)	(79)
Fair Value	57,371	57,798
Corporate bonds | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	52,354	91,959
Gross Unrealized Gains	245	25
Gross Unrealized Losses	(32)	(571)
Fair Value	52,567	91,413
Commercial paper | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	0	17,428
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	0	17,428
Municipal securities | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	23,720	23,743
Gross Unrealized Gains	30	8
Gross Unrealized Losses	(10)	(51)
Fair Value	23,740	23,700
Municipal securities | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	19,483	26,371
Gross Unrealized Gains	10	13
Gross Unrealized Losses	(49)	(160)
Fair Value	19,444	26,224
U.S. government securities | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	137,499	55,729
Gross Unrealized Gains	78	1
Gross Unrealized Losses	(86)	(163)
Fair Value	137,491	55,567
U.S. government securities | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	86,086	66,362
Gross Unrealized Gains	88	19
Gross Unrealized Losses	(111)	(520)
Fair Value	$ 86,063	$ 65,861

INVESTMENTS - Maturity of Avai

INVESTMENTS - Maturity of Available for Sale Securities (Details) $ in Thousands	Jun. 30, 2018USD ($)
Amortized Cost
Due in one year or less	$ 233,490
Due in one to five years	168,019
Total	401,509
Fair Value
Due in one year or less	233,599
Due in one to five years	168,150
Total	$ 401,749

PROPERTY AND EQUIPMENT, NET (De

PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 240,162		$ 240,162		$ 192,812
Less: Accumulated depreciation and amortization	(118,454)		(118,454)		(101,316)
Property and equipment, net	121,708		121,708		91,496
Depreciation	9,300	$ 7,200	17,500	$ 14,500
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	94,241		94,241		77,073
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	81,763		81,763		66,186
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	45,927		45,927		35,063
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 18,231		$ 18,231		$ 14,490

ACQUISITIONS - Narrative (Detai

ACQUISITIONS - Narrative (Details) - USD ($) $ in Thousands	May 31, 2018	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Payment for acquisitions, net of cash acquired			$ 111,828	$ 1,600
Weebly, Inc.
Business Acquisition [Line Items]
Percent of outstanding shares acquired	100.00%
Cash consideration	$ 131,860
Equity consideration (in shares)	2,406,071
Equity consideration fair value	$ 139,396
Payment to settle outstanding vested and unvested employee options	17,700
Post-combination compensation expense	$ 2,600
Acquisition-related costs		$ 1,200	1,200
Cash withheld for indemnification		$ 19,900	$ 19,900
Shares withheld for indemnification (in shares)		372,578	372,578
Immaterial acquisitions
Business Acquisition [Line Items]
Payment for acquisitions, net of cash acquired			$ 9,900

ACQUISITIONS - Schedule of Asse

ACQUISITIONS - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	May 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 255,656	$ 58,327
Weebly, Inc.
Consideration:
Cash	$ 131,860
Stock (2,406,071 shares of common stock)	$ 139,396
Stock (in shares)	2,406,071
Total consideration	$ 271,256
Recognized amounts of identifiable assets acquired and liabilities assumed:
Current assets (inclusive of cash acquired of $25,758)	44,685
Cash acquired	25,758
Total liabilities assumed (including deferred revenue of $22,800)	(32,824)
Deferred revenue	22,800
Total identifiable net assets acquired	81,722
Goodwill	189,534
Total	271,256
Weebly, Inc. | Customer assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	42,700
Weebly, Inc. | Technology assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	14,900
Weebly, Inc. | Trade name
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	11,300
Weebly, Inc. | Intangible other assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	$ 961

GOODWILL (Details)

GOODWILL (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 58,327,000
Acquisitions completed during the six months ended June 30, 2018			197,329,000
Goodwill, ending balance	$ 255,656,000		255,656,000
Goodwill, impairment charges	$ 0	$ 0	$ 0	$ 0

ACQUIRED INTANGIBLE ASSETS - N

ACQUIRED INTANGIBLE ASSETS - Narrative (Details) - business	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	May 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Number of businesses acquired involving intangible assets	2
Weebly, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Percent of outstanding shares acquired			100.00%
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period		13 years
Technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period		5 years
Customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period		11 years
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period		4 years

ACQUIRED INTANGIBLE ASSETS - S

ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 116,633		$ 40,762
Accumulated Amortization	(31,119)		(26,428)
Net	85,514	$ 14,138	14,334	$ 16,452	$ 18,395	$ 19,292
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	1,285		1,285
Accumulated Amortization	(611)		(559)
Net	674		726
Technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	45,978		29,158
Accumulated Amortization	(24,766)		(21,329)
Net	21,212		7,829
Customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	57,109		10,319
Accumulated Amortization	(5,481)		(4,540)
Net	51,628		$ 5,779
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	11,300
Accumulated Amortization	(235)
Net	11,065
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	961
Accumulated Amortization	(26)
Net	$ 935

ACQUIRED INTANGIBLE ASSETS - Ch

ACQUIRED INTANGIBLE ASSETS - Change in Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Finite-lived Intangible Assets [Roll Forward]
Acquired intangible assets, net, beginning of the period	$ 14,138	$ 18,395	$ 14,334	$ 19,292
Acquisitions	74,192	0	75,871	1,224
Amortization expense	2,816	1,943	4,691	4,064
Acquired intangible assets, net, end of the period	$ 85,514	$ 16,452	$ 85,514	$ 16,452

ACQUIRED INTANGIBLE ASSETS - F

ACQUIRED INTANGIBLE ASSETS - Future Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
2018 (remaining 6 months)	$ 7,863
2,019	13,843
2,020	11,638
2,021	10,440
2,022	8,511
Thereafter	33,219
Net	$ 85,514	$ 14,138	$ 14,334	$ 16,452	$ 18,395	$ 19,292

OTHER CONSOLIDATED BALANCE SH63

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventory, net	$ 22,041	$ 16,777
Processing costs receivable	33,861	21,083
Prepaid expenses	16,663	14,473
Accounts receivable, net	17,895	8,606
Deferred hardware costs	0	7,931
Deferred magstripe reader costs	3,034	2,469
Prepaid compensation, current	5,940	0
Other	20,816	15,115
Total	$ 120,250	$ 86,454

OTHER CONSOLIDATED BALANCE SH64

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued payroll	$ 10,229	$ 9,103
Accrued professional fees	9,168	5,638
Accrued advertising and other marketing	11,961	6,723
Processing costs payable	11,205	10,145
Accrued non income tax liabilities	7,504	6,155
Accrued hardware costs	1,806	2,496
Other accrued liabilities	22,943	12,020
Total	$ 74,816	$ 52,280

OTHER CONSOLIDATED BALANCE SH65

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Square Capital payable	$ 10,301	$ 7,671
Square Payroll payable	6,494	2,850
Deferred revenue, current	24,062	5,893
Deferred rent, current	3,691	3,311
Accrued redemptions	1,110	1,036
Other	14,977	7,606
Total	$ 60,635	$ 28,367

OTHER CONSOLIDATED BALANCE SH66

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) - Other Non-Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investment in privately held entity	$ 25,000	$ 25,000
Prepaid compensation, non-current	7,927	0
Deposits	2,646	2,738
Debt issuance costs	650	788
Deferred tax assets	680	519
Other	4,092	2,305
Total	$ 40,995	$ 31,350

OTHER CONSOLIDATED BALANCE SH67

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Statutory liabilities	$ 47,423	$ 40,768
Deferred rent, non-current	21,479	20,349
Deferred purchase consideration	3,900	0
Deferred revenue, non-current	3,093	432
Deferred tax liabilities	148	644
Other	9,808	7,345
Total	$ 85,851	$ 69,538

INDEBTEDNESS - Revolving Credi

INDEBTEDNESS - Revolving Credit Facility, Narrative (Details) - Revolving Credit Facility - Line of Credit - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Nov. 30, 2015	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 375,000,000
Administrative agent fee	$ 100,000
Unused commitment fee percentage	0.15%
Remaining borrowing capacity		$ 375,000,000		$ 375,000,000
Unused commitment fees		$ 100,000	$ 100,000	$ 300,000	$ 300,000
Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
One Month LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
One Month LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%

INDEBTEDNESS - Convertible Seni

INDEBTEDNESS - Convertible Senior Notes, Narrative (Details) - Convertible Debt	Jul. 27, 2018USD ($)	May 25, 2018USD ($)day$ / shares	Mar. 06, 2017USD ($)day$ / shares	Jun. 30, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Conversion price (in USD per share) | $ / shares		$ 77.85	$ 22.95
Carrying amount of equity component				$ 237,920,000
Issuance costs attributable to the liability component				$ 12,694,000
Convertible Senior Notes due in 2023
Debt Instrument [Line Items]
Aggregate principal amount		$ 750,000,000
Over-allotment option as a percentage of a principal amount		15.00%
Over-allotment option		$ 112,500,000
Interest rate		0.50%
Conversion rate		0.0128456
Conversion price (in USD per share) | $ / shares		$ 77.85		$ 77.85
Conversion amount		$ 1,000
Carrying amount of equity component		155,300,000		$ 154,019,000
Effective interest rate of the liability component				4.69%
Discounts and commissions payable		6,000,000
Third party offering costs		800,000
Issuance costs attributable to the liability component		$ 5,600,000		$ 5,524,000
Convertible Senior Notes due in 2023 | Debt Instrument, Conversion Term One
Debt Instrument [Line Items]
Threshold trading days | day		20
Threshold consecutive trading days | day		30
Threshold percentage of stock price trigger		130.00%
Convertible Senior Notes due in 2023 | Debt Instrument Conversion Term Two
Debt Instrument [Line Items]
Threshold trading days | day		5
Threshold consecutive trading days | day		5
Threshold percentage of stock price trigger		98.00%
Convertible Senior Notes due in 2022
Debt Instrument [Line Items]
Aggregate principal amount			$ 400,000,000
Over-allotment option as a percentage of a principal amount			10.00%
Over-allotment option			$ 40,000,000
Interest rate			0.375%
Conversion rate			0.0435749
Conversion price (in USD per share) | $ / shares			$ 22.95	$ 22.95
Conversion amount			$ 1,000
Carrying amount of equity component			86,200,000	$ 83,901,000	$ 83,901,000
Effective interest rate of the liability component				5.34%
Discounts and commissions payable			11,000,000
Third party offering costs			800,000
Issuance costs attributable to the liability component			$ 9,400,000	$ 7,170,000	$ 8,044,000
Convertible Senior Notes due in 2022 | Debt Instrument, Conversion Term One
Debt Instrument [Line Items]
Threshold trading days | day			20
Threshold consecutive trading days | day			30
Threshold percentage of stock price trigger			130.00%
Convertible Senior Notes due in 2022 | Debt Instrument Conversion Term Two
Debt Instrument [Line Items]
Threshold trading days | day			5
Threshold consecutive trading days | day			5
Threshold percentage of stock price trigger			98.00%
Subsequent event | Convertible Senior Notes due in 2022
Debt Instrument [Line Items]
Principal amount of convertible note holder's intent to convert	$ 45,000,000

INDEBTEDNESS - Components of Co

INDEBTEDNESS - Components of Convertible Notes (Details) - Convertible Debt - USD ($) $ in Thousands	Jun. 30, 2018	May 25, 2018	Dec. 31, 2017	Mar. 06, 2017
Debt Instrument [Line Items]
Principal outstanding	$ 1,302,500
Unamortized debt discount	(218,369)
Unamortized debt issuance costs	(12,694)
Net carrying value	1,071,437
Convertible Senior Notes due in 2023
Debt Instrument [Line Items]
Principal outstanding	862,500
Unamortized debt discount	(152,955)
Unamortized debt issuance costs	(5,524)	$ (5,600)
Net carrying value	704,021
Convertible Senior Notes due in 2022
Debt Instrument [Line Items]
Principal outstanding	440,000		$ 440,000
Unamortized debt discount	(65,414)		(73,384)
Unamortized debt issuance costs	(7,170)		(8,044)	$ (9,400)
Net carrying value	$ 367,416		$ 358,572

INDEBTEDNESS - Carrying Amount

INDEBTEDNESS - Carrying Amount of Equity Component of Convertible Notes (Details) - Convertible Debt - USD ($) $ in Thousands	Jun. 30, 2018	May 25, 2018	Dec. 31, 2017	Mar. 06, 2017
Debt Instrument [Line Items]
Amount allocated to conversion option	$ 241,453
Less: allocated issuance costs	(3,533)
Equity component, net	237,920
Convertible Senior Notes due in 2023
Debt Instrument [Line Items]
Amount allocated to conversion option	155,250
Less: allocated issuance costs	(1,231)
Equity component, net	154,019	$ 155,300
Convertible Senior Notes due in 2022
Debt Instrument [Line Items]
Amount allocated to conversion option	86,203		$ 86,203
Less: allocated issuance costs	(2,302)		(2,302)
Equity component, net	$ 83,901		$ 83,901	$ 86,200

INDEBTEDNESS - Interest Expense

INDEBTEDNESS - Interest Expense (Details) - Convertible Debt - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Instrument [Line Items]
Contractual interest expense	$ 850	$ 413	$ 1,263	$ 526
Amortization of debt discount and issuance costs	6,830	4,221	11,223	5,611
Total	$ 7,680	$ 4,634	$ 12,486	$ 6,137
Convertible Senior Notes due in 2023
Debt Instrument [Line Items]
Effective interest rate of the liability component	4.69%		4.69%
Convertible Senior Notes due in 2022
Debt Instrument [Line Items]
Effective interest rate of the liability component	5.34%		5.34%

INDEBTEDNESS - Convertible Note

INDEBTEDNESS - Convertible Note Hedge and Warrant Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	May 25, 2018	Mar. 06, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Instrument [Line Items]
Proceeds from issuance of warrants			$ 112,125	$ 57,244
Convertible Debt
Debt Instrument [Line Items]
Conversion price of convertible debt (in USD per share)	$ 77.85	$ 22.95
Conversion price of convertible debt after effect of warrants and note hedge (in USD per share)	$ 109.26	$ 31.18
Common Stock Warrant
Debt Instrument [Line Items]
Warrants to purchase aggregate shares of capital stock (in shares)	11.1	19.2
Warrants, weighted average exercise price (in USD per share)	$ 109.26	$ 31.18
Proceeds from issuance of warrants	$ 112,100	$ 0
Options
Debt Instrument [Line Items]
Warrants to purchase aggregate shares of capital stock (in shares)	11.1	19.2
Convertible note hedge, option to purchase common stock, price (in USD per share)	$ 77.85	$ 22.95
Cost of convertible note hedge	$ 172,600	$ 92,100

ACCRUED TRANSACTION LOSSES (Det

ACCRUED TRANSACTION LOSSES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Loss Contingency Accrual
Accrued transaction losses, beginning of the period			$ 26,893
Provision for transaction losses			40,007	$ 30,292
Accrued transaction losses, end of the period	$ 29,207		29,207
Transaction Losses
Loss Contingency Accrual
Accrued transaction losses, beginning of the period	28,309	$ 20,444	26,893	20,064
Provision for transaction losses	14,087	13,076	28,345	24,634
Charge-offs to accrued transaction losses	(13,189)	(11,065)	(26,031)	(22,243)
Accrued transaction losses, end of the period	$ 29,207	$ 22,455	$ 29,207	$ 22,455

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 604	$ 472	$ 779	$ 981
Effective tax rate	(11.40%)	(3.00%)	(2.70%)	(3.30%)

STOCKHOLDERS' EQUITY - Changes

STOCKHOLDERS' EQUITY - Changes in Stockholder's Equity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2017			$ 786,333
Net loss	$ (5,906)	$ (15,962)	(29,892)	$ (31,052)
Exercise of stock options			54,621
Purchases under the employee stock purchase plan			12,578
Vesting of early exercised stock options and other			126
Issuance of common stock in connection with business combination			139,396
Replacement stock awards issued in connection with acquisition			757
Conversion feature of convertible senior notes, due 2023, net of allocated costs			154,019
Purchase of bond hedges in conjunction with issuance of convertible senior notes, due 2023			(172,586)
Sale of warrants in conjunction with issuance of convertible senior notes, due 2023			112,125
Share-based compensation			103,196
Tax withholding related to vesting of restricted stock units			(68,575)
Cumulative adjustment for adoption of ASC 606					$ (4,586)
Recovery of common stock in connection with indemnification settlement agreement			(2,745)
Change in other comprehensive loss			(3,138)
Balance at June 30, 2018	$ 1,081,629		$ 1,081,629

STOCKHOLDERS' EQUITY - Common

STOCKHOLDERS' EQUITY - Common Stock and Warrants Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	May 25, 2018	Mar. 06, 2017	Jun. 30, 2018	Jun. 30, 2017	Apr. 30, 2018	Dec. 31, 2017	Dec. 31, 2014
Class of Stock [Line Items]
Proceeds from issuance of warrants			$ 112,125	$ 57,244
Caviar, Inc.
Class of Stock [Line Items]
Shares issued for consideration withheld for indemnification purposes (in shares)							1,291,979
Shares issued for consideration withheld for indemnification purposes, released to former owners (in shares)					822,085
Shares issued for consideration withheld for indemnification purposes, forfeited back to Company (in shares)					469,894
Indemnification asset							$ 2,800
Common Stock Warrant
Class of Stock [Line Items]
Warrants to purchase aggregate shares of capital stock (in shares)	11,100,000	19,200,000
Warrants, weighted average exercise price (in USD per share)	$ 109.26	$ 31.18
Proceeds from issuance of warrants	$ 112,100	$ 0
Class A
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			1,000,000,000			1,000,000,000
Common stock, par value (in USD per share)			$ 0.00			$ 0.00
Common stock, shares outstanding (in shares)			297,371,047			280,400,813
Class B
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			500,000,000			500,000,000
Common stock, par value (in USD per share)			$ 0.00			$ 0.00
Common stock, shares outstanding (in shares)			109,580,981			114,793,262

STOCKHOLDERS' EQUITY - Share B

STOCKHOLDERS' EQUITY - Share Based Compensation Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)shares	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)planshares	Jun. 30, 2017USD ($)	Nov. 17, 2015shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share based compensation plans | plan			2
Employee stock purchase plan, compensation expense | $	$ 52,119	$ 39,593	$ 98,943	$ 71,263
Capitalized share-based compensation expense | $	2,700	700	4,300	1,200
Unrecognized compensation cost, options | $	531,500		531,500
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, compensation expense | $	$ 2,000	$ 1,200	$ 4,200	$ 3,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, period for recognition			2 years 10 months 13 days
2009 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)	0		0
2009 Stock Option Plan | Stock options and restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments outstanding (in shares)	34,740,852		34,740,852
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)	63,326,561		63,326,561
Shares reserved for future issuance (in shares)					30,000,000
Shares reserved for future issuance, percentage of annual increase			5.00%
2015 Equity Incentive Plan | Stock options and restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments outstanding (in shares)	26,273,466		26,273,466
2015 Equity Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance, amount of annual increase (in shares)	40,000,000		40,000,000

STOCKHOLDERS' EQUITY - Stock O

STOCKHOLDERS' EQUITY - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018
Number of Stock Options Outstanding
Beginning balance (in shares)	47,270,091
Granted (in shares)	783,625
Exercised (in shares)	(7,460,458)
Forfeited (in shares)	(454,154)
Ending balance (in shares)	40,139,104	47,270,091
Weighted Average Exercise Price
Beginning balance (in USD per share)	$ 8.67
Granted (in USD per share)	44.75
Exercised (in USD per share)	7.32
Forfeited (in USD per share)	12.21
Ending balance (in USD per share)	$ 8.67	$ 8.67	$ 9.58
Options Exercisable
Options exercisable (in shares)			37,006,235
Options exercisable (in USD per share)			$ 8.62
Additional Disclosures
Weighted average remaining contractual term, options outstanding	6 years 2 months 15 days	6 years 6 months 7 days
Weighted average remaining contractual term, options exercisable	6 years 7 days
Aggregate intrinsic value, options outstanding		$ 1,229,103	$ 2,089,523
Aggregate intrinsic value, options exercisable			$ 1,962,153

STOCKHOLDERS' EQUITY - RSU Act

STOCKHOLDERS' EQUITY - RSU Activity (Details) - RSAs and RSUs	6 Months Ended
	Jun. 30, 2018$ / sharesshares
Number of shares
Beginning balance (in shares) | shares	21,317,525
Granted (in shares) | shares	4,439,906
Vested (in shares) | shares	(3,736,968)
Forfeited (in shares) | shares	(1,145,249)
Ending balance (in shares) | shares	20,875,214
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share) | $ / shares	$ 17.84
Granted (in USD per share) | $ / shares	45.62
Vested (in USD per share) | $ / shares	16.52
Forfeited (in USD per share) | $ / shares	17
Ending balance (in USD per share) | $ / shares	$ 24.03

STOCKHOLDERS' EQUITY - Stock81

STOCKHOLDERS' EQUITY - Stock Option Fair Value Assumptions (Details) - Stock options	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate	2.92%	1.88%	2.92%	1.88%
Expected volatility	30.87%	32.22%	30.87%	32.22%
Expected term (years)	6 years 2 months 10 days	6 years 7 days	6 years 2 months 10 days	6 years 7 days

STOCKHOLDERS' EQUITY - Effects

STOCKHOLDERS' EQUITY - Effects of Share-Based Compensation on Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 52,119	$ 39,593	$ 98,943	$ 71,263
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	30	18	61	18
Product development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	33,806	25,136	64,288	44,492
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	5,634	4,355	10,595	8,290
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 12,649	$ 10,084	$ 23,999	$ 18,463

LOSS PER SHARE - Calculation o

LOSS PER SHARE - Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net loss	$ (5,906)	$ (15,962)	$ (29,892)	$ (31,052)
Basic shares:
Weighted-average common shares outstanding (in shares)	403,390	377,959	400,318	373,291
Weighted-average unvested shares (in shares)	(89)	(1,602)	(694)	(1,718)
Weighted-average shares used to compute basic net loss per share (in shares)	403,301	376,357	399,624	371,573
Diluted shares:
Weighted-average shares used to compute diluted loss per share (in shares)	403,301	376,357	399,624	371,573
Net loss per share:
Basic (in USD per share)	$ (0.01)	$ (0.04)	$ (0.07)	$ (0.08)
Diluted (in USD per share)	$ (0.01)	$ (0.04)	$ (0.07)	$ (0.08)

LOSS PER SHARE - Antidilutive

LOSS PER SHARE - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	May 25, 2018	Mar. 06, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	86,772	103,034	86,895	100,656
Stock options and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	62,908	81,919	64,635	83,406
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	23,605	19,173	21,377	15,173
Unvested shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	89	1,602	694	1,718
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	170	340	189	359
Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion price of convertible debt (in USD per share)					$ 77.85	$ 22.95
Convertible Debt | Convertible Senior Notes due in 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion price of convertible debt (in USD per share)	$ 22.95		$ 22.95			$ 22.95
Convertible Debt | Convertible Senior Notes due in 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion price of convertible debt (in USD per share)	$ 77.85		$ 77.85		$ 77.85

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES - Operating and Capital Leases- Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Operating leases, rent expense	$ 5.3	$ 3.1	$ 9.8	$ 5.9

COMMITMENTS AND CONTINGENCIES86

COMMITMENTS AND CONTINGENCIES - Schedule of Future Payments Under Operating and Capital Leases (Details) $ in Thousands	Jun. 30, 2018USD ($)
Capital
2018 (remaining 6 months)	$ 2,599
2,019	5,089
2,020	2,501
2,021	46
2,022	2
Thereafter	0
Total	10,237
Less amount representing interest	(14)
Present value of capital lease obligations	10,223
Less current portion of capital lease obligation	(5,190)
Non-current portion of capital lease obligation	5,033
Operating
2018 (remaining 6 months)	13,852
2,019	32,823
2,020	34,437
2,021	34,473
2,022	35,038
Thereafter	34,037
Total	$ 184,660

SEGMENT AND GEOGRAPHICAL INFO87

SEGMENT AND GEOGRAPHICAL INFORMATION - Narrative (Details)	6 Months Ended
	Jun. 30, 2018segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

SEGMENT AND GEOGRAPHICAL INFO88

SEGMENT AND GEOGRAPHICAL INFORMATION - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 814,938	$ 551,505	$ 1,483,541	$ 1,013,059
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	777,335	530,008	1,417,508	974,907
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 37,603	$ 21,497	$ 66,033	$ 38,152

SEGMENT AND GEOGRAPHICAL INFO89

SEGMENT AND GEOGRAPHICAL INFORMATION - Long-lived Assets by Geography (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 462,916	$ 164,157
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	456,159	158,820
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 6,757	$ 5,337

SUPPLEMENTAL CASH FLOW INFORM90

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Supplemental Cash Flow Data:
Cash paid for interest	$ 1,108	$ 284
Cash paid for income taxes	854	850
Supplemental disclosures of non-cash investing and financing activities:
Change in purchases of property and equipment in accounts payable and accrued expenses	9,708	1,454
Unpaid business acquisition purchase price	3,995	644
Fair value of common stock issued related to business combination	(139,396)	0
Recovery of common stock in connection with indemnification settlement agreement	$ 2,745	$ 0