Block (XYZ) 10-Q 2 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 25, 2016
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	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		166,302,906
Class B
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		185,836,069

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 437,900	$ 470,775
Short-term investments	76,427	0
Restricted cash	13,559	13,537
Settlements receivable	233,812	142,727
Loans held for sale	28,817	604
Merchant cash advance receivable, net	8,268	36,473
Other current assets	44,244	41,447
Total current assets	843,027	705,563
Property and equipment, net	89,957	87,222
Goodwill	56,699	56,699
Acquired intangible assets, net	20,252	26,776
Long-term investments	15,478	0
Restricted cash	23,137	14,686
Other assets	3,658	3,826
Total assets	1,052,208	894,772
Current liabilities:
Accounts payable	13,719	18,869
Customers payable	364,434	224,811
Accrued transaction losses	21,428	17,176
Accrued expenses	41,943	44,401
Other current liabilities	44,500	28,945
Total current liabilities	486,024	334,202
Other liabilities	55,795	52,522
Total liabilities	541,819	386,724
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0000001 par value: 100,000,000 shares authorized at September 30, 2016 and December 31, 2015. None issued and outstanding at September 30, 2016 and December 31, 2015.	0	0
Common stock, $0.0000001 par value: 1,000,000,000 Class A shares authorized at September 30, 2016 and December 31, 2015; 162,988,864 and 31,717,133 issued and outstanding at September 30, 2016 and December 31, 2015, respectively. 500,000,000 Class B shares authorized at both September 30, 2016 and December 31, 2015; 188,328,922 and 303,232,312 issued and outstanding at September 30, 2016 and December 31, 2015, respectively.	0	0
Additional paid-in capital	1,274,248	1,116,882
Accumulated deficit	(764,072)	(607,649)
Accumulated other comprehensive income (loss)	213	(1,185)
Total stockholders’ equity	510,389	508,048
Total liabilities and stockholders’ equity	$ 1,052,208	$ 894,772

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
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)	162,988,864	31,717,133
Common stock, shares outstanding (in shares)	162,988,864	31,717,133
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)	188,328,922	303,232,312
Common stock, shares outstanding (in shares)	188,328,922	303,232,312

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue:
Hardware revenue	$ 8,171	$ 4,207	$ 35,438	$ 10,002
Total net revenue	439,002	332,188	1,256,804	892,758
Cost of revenue:
Hardware costs	15,689	5,726	56,444	16,636
Amortization of acquired technology	1,886	1,142	6,142	2,886
Total cost of revenue	288,688	235,878	847,291	631,821
Gross profit	150,314	96,310	409,513	260,937
Operating expenses:
Product development	70,418	55,020	203,648	140,452
Sales and marketing	46,754	39,259	124,470	107,170
General and administrative	52,075	37,820	198,966	97,743
Transaction, loan and advance losses	12,885	16,005	38,201	40,840
Amortization of acquired customer assets	164	423	703	1,373
Total operating expenses	182,296	148,527	565,988	387,578
Operating loss	(31,982)	(52,217)	(156,475)	(126,641)
Interest (income) and expense, net	(183)	137	(243)	995
Other (income) and expense, net	294	644	(690)	1,390
Loss before income tax	(32,093)	(52,998)	(155,542)	(129,026)
Provision for income taxes	230	932	881	2,502
Net loss	$ (32,323)	$ (53,930)	$ (156,423)	$ (131,528)
Net loss per share:
Basic (in USD per share)	$ (0.09)	$ (0.35)	$ (0.46)	$ (0.88)
Diluted (in USD per share)	$ (0.09)	$ (0.35)	$ (0.46)	$ (0.88)
Weighted-average shares used to compute net loss per share
Basic (in shares)	343,893	152,334	336,593	149,058
Diluted (in shares)	343,893	152,334	336,593	149,058
Transaction | Customers Other than Starbucks
Revenue:
Revenue	$ 388,347	$ 280,955	$ 1,053,664	$ 751,929
Cost of revenue:
Transaction, software, and data product costs	254,061	182,007	683,194	479,937
Transaction | Starbucks
Revenue:
Revenue	7,164	32,332	78,869	95,199
Cost of revenue:
Transaction, software, and data product costs	4,528	41,410	69,810	118,542
Software and data product
Revenue:
Revenue	35,320	14,694	88,833	35,628
Cost of revenue:
Transaction, software, and data product costs	$ 12,524	$ 5,593	$ 31,701	$ 13,820

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (32,323)	$ (53,930)	$ (156,423)	$ (131,528)
Net foreign currency translation adjustments	127	(198)	722	(455)
Net unrealized gain (loss) on revaluation of intercompany loans	74	80	656	(15)
Net unrealized gain (loss) on marketable securities	(60)	0	20	0
Total comprehensive loss	$ (32,182)	$ (54,048)	$ (155,025)	$ (131,998)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (156,423)	$ (131,528)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	27,817	18,526
Provision for transaction losses	36,875	32,967
Provision for (reduction in) uncollectible merchant cash advances	509	4,616
Deferred provision for income taxes	(104)	(207)
Loss on disposal of property and equipment	(88)	240
Changes in operating assets and liabilities:
Settlements receivable	(91,390)	(40,729)
Purchase of loans held for sale	(421,243)	0
Proceeds from sales and principal payments of loans held for sale	393,221	0
Merchant cash advance receivable	27,696	(18,725)
Other current assets	(3,011)	(4,457)
Other assets	145	1,102
Accounts payable	(867)	2,048
Customers payable	139,105	89,446
Charge-offs and recoveries to accrued transaction losses	(32,623)	(25,415)
Accrued expenses	86	13,950
Other current liabilities	15,255	1,524
Other noncurrent liabilities	2,376	8,801
Net cash provided by operating activities	42,235	3,130
Cash flows from investing activities:
Purchase of marketable securities	(139,103)	0
Proceeds from maturities of marketable securities	26,268	0
Proceeds from sale of marketable securities	20,962	0
Purchase of property and equipment	(19,674)	(30,724)
Payment for acquisition of intangible assets	(400)	(110)
Change in restricted cash	(8,473)	(252)
Business acquisitions (net of cash acquired)	0	(4,500)
Net cash used in investing activities	(120,420)	(35,586)
Cash flows from financing activities:
Principal payments on debt	0	(30,000)
Payments of offering costs related to initial public offering	(5,530)	0
Proceeds from issuances of common stock from the exercise of options and employee stock purchase plan	48,304	12,209
Net cash provided by (used in) financing activities	42,774	(17,791)
Effect of foreign exchange rate changes on cash and cash equivalents	2,536	(970)
Net decrease in cash and cash equivalents	(32,875)	(51,217)
Cash and cash equivalents, beginning of period	470,775	225,300
Cash and cash equivalents, end of period	437,900	174,083
Customers Other than Starbucks
Adjustments to reconcile net loss to net cash provided by operating activities:
Share-based compensation	104,899	49,486
Starbucks
Adjustments to reconcile net loss to net cash provided by operating activities:
Share-based compensation	$ 0	$ 1,485

DESCRIPTION OF BUSINESS AND SUM

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2016
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 of all sizes start, run, and grow their businesses – from payment processing to point of sale, hardware to software, business loans to payroll and more. Businesses and individuals can also use Square Cash, an easy way to send and receive money, as well as Caviar, a food delivery service for popular restaurants. Square was founded in 2009 and is headquartered in San Francisco, with offices in the United States, Canada, Japan, and Australia. Initial Public Offering In November 2015 , the Company completed its Initial Public Offering (IPO) in which it issued and sold 29,700,000 shares of Class A common stock at a public offering price of $9.00 per share and a selling stockholder sold 1,350,000 shares of Class A common stock. The Company did not receive any proceeds from the sale of shares by the selling stockholder. The total net proceeds received by the Company from the IPO were $245.7 million after deducting underwriting discounts and commissions of $14.7 million and other offering expenses of approximately $6.9 million . Out of Period Adjustments During the three months ended June 30, 2016, the Company recorded an out of period adjustment of $6.0 million to transaction, loan and advance losses as a result of a correction to the calculation of its reserve for transaction losses. The adjustment was recorded to correct an understatement of transaction losses in prior periods. Of the total amount of this adjustment, $0.5 million is related to the three months ended March 31, 2016, and $2.6 million , $1.6 million and $ 1.0 million is related to the years ended December 31, 2015, 2014, and 2013, respectively. The remaining $0.3 million is related to historical periods. The Company does not believe that such amounts are material with respect to the estimated operating loss or estimated net loss for the current fiscal year or any previously reported consolidated financial statements. Litigation Settlement On June 8, 2016 , a final, definitive settlement agreement (Settlement Agreement) was entered into by Robert E. Morley, REM Holdings 3, LLC, Jack Dorsey, Jim McKelvey, and the Company. The Settlement Agreement required an aggregate total payment of $50 million to plaintiffs, including meaningful contributions by Mr. Dorsey and Mr. McKelvey. The Company made a payment of $48 million to plaintiffs and met its obligations under the Settlement Agreement. This amount was classified within general and administrative expenses on the condensed consolidated statements of operations for the nine months ended September 30, 2016 . On June 17, 2016 , the Court entered an Order dismissing the complaints in their entirety, with prejudice. 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, 2015 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 nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 , 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, 2015 . 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. Significant estimates, judgments, and assumptions in these consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, provision for uncollectible receivables related to merchant cash advances (MCAs), valuation of loans held for sale, business combinations, goodwill and intangible assets, income taxes, and share-based compensation. Concentration of Credit Risk For the three and nine months ended September 30, 2016 , the Company had no customer that accounted for greater than 10% of total net revenue. For the three and nine months ended September 30, 2015 , the Company had no customer other than Starbucks that accounted for greater than 10% of total net revenue. The Company had three third-party processors that represented approximately 47% , 39% , and 11% of settlements receivable as of September 30, 2016 . The same three parties represented approximately 56% , 23% , and 16% of settlements receivable as of December 31, 2015 . The Company places its cash and cash equivalents and investments in marketable securities with large creditworthy U.S. financial institutions. Balances in these accounts may exceed federally insured limits at times. Significant Accounting Policies Except as described below, there have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2016 , as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . Loans Held for Sale The Company provides loans to sellers prequalified through an analysis of the aggregated data of the seller’s business which includes, but is not limited to, the seller’s historical processing volumes, transaction count, chargebacks, growth, and length of time as a Square customer. The loans are originated by a bank, from whom the Company purchases the loans obtaining all rights, title, and interest. The loans are classified as held for sale upon purchase, as it is the Company’s intent to sell all of its rights, title, and interest in these loans to third-party investors for an up-front origination fee when the loans are sold. The Company also earns a servicing fee by continuing to service the loans by remitting monies to the third-party investors. Revenue from origination fees are recognized upon transfer of title to investors and servicing revenue is recognized as servicing is delivered. A loan that is initially designated as held for sale may be reclassified to held for investment if and when the Company's intent for that loan changes. There have been no reclassifications made to date. Loans are recorded at the lower of cost or fair value. To determine the fair value of loans, the Company utilizes industry standard modeling, such as discounted cash flow models, to arrive at an estimate of fair value. Recently Issued Accounting Standards In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers , and issued subsequent amendments to the initial guidance within ASU 2015-04, ASU 2016-08, ASU 2016-10, and ASU 2016-12. The new guidance will replace all current U.S. GAAP guidance on this topic and eliminate all industry specific guidance. The core principal of this new guidance is that revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration for which the Company expects to be entitled in exchange for those goods or services. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted. The guidance can be applied either retrospectively to each period presented or as a cumulative effect adjustment as of the date of adoption. The Company has not yet selected a transition method and is evaluating the impact of adopting this new accounting standard update on the consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-04, Recognition of Breakage for Certain Prepaid Stored-Value Products. This guidance specifies how prepaid stored-value product liabilities should be derecognized, thereby eliminating the current and potential future diversity in practice. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, 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. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting , which is intended to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2016, 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. 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. In August 2016, the FASB issues ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments. This guidance addresses several specific cash flow issues with the objective of reducing the existing diversity in practice. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, 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.

RESTRICTED CASH

RESTRICTED CASH	9 Months Ended
	Sep. 30, 2016
Cash and Cash Equivalents [Abstract]
RESTRICTED CASH	RESTRICTED CASH As of September 30, 2016 and December 31, 2015 , restricted cash of $13.6 million and $13.5 million , respectively, is related to pledged cash deposited into savings accounts at the financial institutions that process the Company's sellers' payment transactions. The Company uses the restricted cash to secure letters of credit with the financial institutions 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 condensed 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. As of September 30, 2016 and December 31, 2015 , the remaining restricted cash of $23.1 million and $14.7 million , respectively, is primarily related to cash deposited into money market funds that is used as collateral pursuant to multi-year lease agreements entered into in 2012 and 2014 (see Note 17 ) and as collateral pursuant to an agreement with the originating bank for the Company's loan product. The Company has recorded this amount as a non-current asset on the condensed consolidated balance sheets as the terms extend beyond one year.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2016
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): September 30, 2016 December 31, 2015 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash and Cash Equivalents: Money market funds $ 209,364 $ — $ — $ 337,234 $ — $ — Commercial paper — 1,500 — — — — Short-term securities: U.S. agency securities — 13,088 — — — — Corporate bonds — 19,787 — — — — Commercial paper — 17,455 — — — — Municipal securities — 6,529 — U.S. government securities 19,568 — — — — — Long-term securities: — — — U.S. agency securities — 6,519 — — — — Corporate bonds — 4,423 — — — — Municipal securities — 3,033 — — — — U.S. government securities 1,503 — — — — — Total $ 230,435 $ 72,334 $ — $ 337,234 $ — $ — Loans are recorded at the lower of cost or fair value. To determine the fair value of loans, the Company utilizes industry-standard valuation modeling, such as discounted cash flow models, to arrive at an estimate of fair value. A summary of loans disclosed at fair value on a recurring basis is as follows (in thousands): September 30, 2016 Carrying Value Fair Value (Level 3) Loans held for sale 28,817 29,778 Total 28,817 29,778 As of December 31, 2015 , the difference between the fair value of loans and the carrying value was insignificant. The carrying amounts of certain financial instruments, including cash equivalents, settlements receivable, merchant cash advance receivable, accounts payable, customers payable, and settlements payable, approximate their fair values due to their short-term nature. 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 nine months ended September 30, 2016 and 2015 , the Company did not have any transfers in or out of Level 1, Level 2, or Level 3 assets or liabilities.

INVESTMENTS

INVESTMENTS	9 Months Ended
	Sep. 30, 2016
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 September 30, 2016 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term securities: U.S. agency securities $ 13,076 $ 12 $ — $ 13,088 Corporate bonds 19,795 — (8 ) 19,787 Commercial paper 17,455 — — 17,455 Municipal securities 6,530 — (1 ) 6,529 U.S. government securities 19,552 16 — 19,568 Total $ 76,408 $ 28 $ (9 ) $ 76,427 Long-term securities: U.S. agency securities $ 6,508 $ 11 $ — $ 6,519 Corporate bonds 4,419 4 — 4,423 Municipal securities 3,038 — (5 ) 3,033 U.S. government securities 1,500 3 — 1,503 Total $ 15,465 $ 18 $ (5 ) $ 15,478 For the three and nine months ended September 30, 2016 , gains or losses realized on the sale of investments were insignificant. 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 until a recovery of fair value, or 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 as of September 30, 2016 . The contractual maturities of the Company's short-term and long-term investments as of September 30, 2016 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 76,408 $ 76,427 Due in one to five years 15,465 15,478 Total $ 91,873 $ 91,905

ALLOWANCE FOR MERCHANT CASH ADV

ALLOWANCE FOR MERCHANT CASH ADVANCE LOSSES	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
ALLOWANCE FOR MERCHANT CASH ADVANCE LOSSES	ALLOWANCE FOR MERCHANT CASH ADVANCE LOSSES The following table summarizes the activities of the Company’s allowance for uncollectible merchant cash advance receivables (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Allowance for uncollectible MCA receivables, beginning of the period $ 5,091 $ 5,277 $ 7,443 $ 2,431 Provision for uncollectible MCA receivables 602 1,468 509 4,616 MCA receivables charged off (855 ) (809 ) (3,114 ) (1,111 ) Allowance for uncollectible MCA receivables, end of the period $ 4,838 $ 5,936 $ 4,838 $ 5,936 As of March 31, 2016, the Company had fully transitioned from offering MCAs to loans. Activity in the table above includes updates to the Company's provision estimates for historical balances and charge offs of certain MCA receivables based on payment inactivity.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	PROPERTY AND EQUIPMENT, NET The following is a summary of property, equipment, and internally-developed software at cost, less accumulated depreciation and amortization (in thousands): September 30, December 31, Computer equipment $ 50,520 $ 43,531 Office furniture and equipment 10,110 9,339 Leasehold improvements 72,308 65,298 Capitalized software 22,761 14,533 Construction in process 670 490 Total 156,369 133,191 Less: Accumulated depreciation and amortization (66,412 ) (45,969 ) Property and equipment, net $ 89,957 $ 87,222 Depreciation and amortization expense on property and equipment was $7.6 million and $20.9 million for the three and nine months ended September 30, 2016 , respectively. Depreciation and amortization expense on property and equipment was $5.0 million and $14.2 million for the three and nine months ended September 30, 2015 , respectively.

GOODWILL

GOODWILL	9 Months Ended
	Sep. 30, 2016
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. As of both September 30, 2016 and December 31, 2015 , goodwill was $56.7 million . 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	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
ACQUIRED INTANGIBLE ASSETS	ACQUIRED INTANGIBLE ASSETS The following table presents the detail of acquired intangible assets as of the periods presented (in thousands): Balance as of September 30, 2016 Cost Accumulated Amortization Net Patent $ 1,285 $ (427 ) $ 858 Technology Assets 29,045 (12,786 ) 16,259 Customer Assets 6,645 (3,510 ) 3,135 Total $ 36,975 $ (16,723 ) $ 20,252 Balance as of December 31, 2015 Cost Accumulated Amortization Net Patent $ 1,285 $ (348 ) $ 937 Technology Assets 28,645 (6,644 ) 22,001 Customer Assets 6,645 (2,807 ) 3,838 Total $ 36,575 $ (9,799 ) $ 26,776 The weighted average amortization periods for acquired patents, acquired technology, and customer intangible assets are approximately 13 years , three years , and six years , respectively. Amortization expense associated with other intangible assets was $2.1 million and $6.9 million for the three and nine months ended September 30, 2016 , respectively. Amortization expense associated with other intangible assets was $1.6 million and $4.3 million for the three and nine months ended September 30, 2015 , respectively. The total estimated annual future amortization expense of these intangible assets as of September 30, 2016 is as follows (in thousands): 2016 (remaining 3 months) $ 2,048 2017 7,187 2018 5,687 2019 2,983 2020 1,087 Thereafter 1,260 Total $ 20,252

OTHER CONSOLIDATED BALANCE SHEE

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT)	9 Months Ended
	Sep. 30, 2016
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): September 30, December 31, Accounts receivable $ 7,407 $ 4,808 Prepaid expenses 3,734 7,101 Deferred reader costs 3,869 4,018 Inventory 14,695 11,864 Tenant improvement reimbursement receivable 1,189 1,788 Deferred hardware costs 2,839 1,709 Processing costs receivable 4,470 7,847 Other 6,041 2,312 Total $ 44,244 $ 41,447 Accrued Expenses The following table presents the detail of accrued expenses (in thousands): September 30, December 31, Accrued hardware costs $ 6,345 $ 11,622 Processing costs payable 7,182 11,417 Accrued professional fees 4,247 7,642 Accrued payroll 6,712 2,660 Accrued marketing 7,147 2,443 Other accrued liabilities 10,310 8,617 Total $ 41,943 $ 44,401 Other Current Liabilities The following table presents the detail of other current liabilities (in thousands): September 30, December 31, Settlements payable 27,515 $ 13,105 Employee early exercised stock options 924 2,141 Accrued redemptions 1,369 1,066 Current portion of deferred rent 2,750 2,393 Deferred revenue 5,303 6,623 Other 6,639 3,617 Total $ 44,500 $ 28,945 OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) Other Non-Current Assets The following table presents the detail of other non-current assets (in thousands): September 30, December 31, Deposits $ 2,104 $ 1,993 Deferred tax assets 301 188 Other 1,253 1,645 Total $ 3,658 $ 3,826 Other Non-Current Liabilities The following table presents the detail of other non-current liabilities (in thousands): September 30, December 31, Deferred rent $ 23,790 $ 25,543 Employee early exercised stock options 201 1,128 Deferred tax liabilities 285 299 Statutory liabilities 27,554 25,492 Other 3,965 60 Total $ 55,795 $ 52,522

OTHER CONSOLIDATED BALANCE SH16

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT)	9 Months Ended
	Sep. 30, 2016
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): September 30, December 31, Accounts receivable $ 7,407 $ 4,808 Prepaid expenses 3,734 7,101 Deferred reader costs 3,869 4,018 Inventory 14,695 11,864 Tenant improvement reimbursement receivable 1,189 1,788 Deferred hardware costs 2,839 1,709 Processing costs receivable 4,470 7,847 Other 6,041 2,312 Total $ 44,244 $ 41,447 Accrued Expenses The following table presents the detail of accrued expenses (in thousands): September 30, December 31, Accrued hardware costs $ 6,345 $ 11,622 Processing costs payable 7,182 11,417 Accrued professional fees 4,247 7,642 Accrued payroll 6,712 2,660 Accrued marketing 7,147 2,443 Other accrued liabilities 10,310 8,617 Total $ 41,943 $ 44,401 Other Current Liabilities The following table presents the detail of other current liabilities (in thousands): September 30, December 31, Settlements payable 27,515 $ 13,105 Employee early exercised stock options 924 2,141 Accrued redemptions 1,369 1,066 Current portion of deferred rent 2,750 2,393 Deferred revenue 5,303 6,623 Other 6,639 3,617 Total $ 44,500 $ 28,945 OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) Other Non-Current Assets The following table presents the detail of other non-current assets (in thousands): September 30, December 31, Deposits $ 2,104 $ 1,993 Deferred tax assets 301 188 Other 1,253 1,645 Total $ 3,658 $ 3,826 Other Non-Current Liabilities The following table presents the detail of other non-current liabilities (in thousands): September 30, December 31, Deferred rent $ 23,790 $ 25,543 Employee early exercised stock options 201 1,128 Deferred tax liabilities 285 299 Statutory liabilities 27,554 25,492 Other 3,965 60 Total $ 55,795 $ 52,522

DEBT

DEBT	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
DEBT	DEBT 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 $0.4 million in unused commitment fees during the three and nine months ended September 30, 2016 , respectively.

ACCRUED TRANSACTION LOSSES

ACCRUED TRANSACTION LOSSES	9 Months Ended
	Sep. 30, 2016
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. Recoveries are reflected as a reduction in the reserve for transaction losses when the recovery occurs. The following table summarizes the activities of the Company’s reserve for transaction losses (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Accrued transaction losses, beginning of the period $ 16,093 $ 15,844 $ 17,176 $ 8,452 Provision for transaction losses 13,483 11,401 36,875 32,967 Charge-offs and recoveries to accrued transaction losses (8,148 ) (11,241 ) (32,623 ) (25,415 ) Accrued transaction losses, end of the period $ 21,428 $ 16,004 $ 21,428 $ 16,004

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company recorded an income tax expense of $0.2 million and $0.9 million for the three and nine months ended September 30, 2016 , respectively, compared to income tax expense of $0.9 million and $2.5 million for the three and nine months ended September 30, 2015 , respectively. The income tax expense recorded for the three and nine months ended September 30, 2016 was primarily due to state and foreign income tax expense. The Company’s effective tax rate was approximately (0.7)% and (0.6)% for the three and nine months ended September 30, 2016 , respectively, compared to an effective tax rate of (1.8)% and (1.9)% for the three and nine months ended September 30, 2015 , respectively. The difference between the effective tax rate and the federal statutory tax rate for the three and nine months ended September 30, 2016 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 September 30, 2016 , 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 nine months ended September 30, 2016 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.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY 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 September 30, 2016 , 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 September 30, 2016 , there were 162,988,864 shares of Class A common stock and 188,328,922 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, Class B shareholders are able to convert their shares into Class A common stock. 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. Beginning November 17, 2015, no additional securities will be issued under the 2009 Plan. Under the 2015 Plan, shares of common stock are reserved for the issuance of incentive and nonstatutory stock options, restricted stock awards, restricted stock units (RSUs), performance shares, and stock bonuses to qualified employees, directors, and consultants. The shares may 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. As of September 30, 2016 , the total number of shares subject to stock options and RSUs outstanding under the 2015 Plan was 19,037,766 , and 35,373,551 shares were available for future issuance. As of September 30, 2016 , the total number of shares subject to stock options and RSUs outstanding under the 2009 Plan was 82,934,307 . A summary of stock option activity for the nine months ended September 30, 2016 is as follows (in thousands, except share and per share data): Number of Stock Options Outstanding Weighted Weighted Aggregate Balance as of December 31, 2015 107,515,554 $ 6.99 7.87 $ 656,194 Granted 1,767,320 13.49 Exercised (13,559,723 ) 3.02 Forfeited (9,020,899 ) $ 10.99 Balance as of September 30, 2016 86,702,252 7.32 7.40 418,923 Options vested and expected to vest as of September 30, 2016 81,679,340 7.10 6.81 410,515 Options exercisable as of September 30, 2016 82,443,845 7.15 7.31 411,791 Restricted Stock Activity Activity related to RSUs during the nine months ended September 30, 2016 is set forth below: Number of Weighted Unvested as of December 31, 2015 3,632,765 $ 13.14 Granted 14,546,288 12.12 Vested (1,780,873 ) 12.48 Forfeited (1,128,359 ) 13.09 Unvested as of September 30, 2016 15,269,821 $ 12.25 Share-Based Compensation The fair value of stock options and employee stock purchase plan shares granted to employees is estimated on the date of grant using the Black-Scholes-Merton option valuation model. Effective August 31, 2015, the Company modified all of its nonstatutory stock option grants to extend the exercise term for terminated employees who have completed two years of service. In the event of a termination, the modified expiration date will be the earlier of (i) three years from termination or (ii) one year following an initial public offering, if in each case, the date of termination occurs between August 31, 2015 and the nine-month anniversary of the initial public offering. In all cases, the grants remain subject to earlier expiration in accordance with their original terms. During the three and nine months ended September 30, 2016 , share-based compensation expense included $0.6 million and $2.0 million , respectively, related to the vested portion of the impacted options, as a result of the modification. The Company will incur an additional $5.2 million of share-based compensation expense over the remaining vesting periods of the impacted options. The fair value of stock options granted was estimated using the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Dividend yield — % — % — % — % Risk-free interest rate 1.31 % 1.69 % 1.54 % 1.73 % Expected volatility 43.51 % 44.56 % 42.74 % 47.91 % Expected term (years) 6.08 5.86 6.08 6.06 The following table summarizes the effects of share-based compensation on the Company's condensed consolidated statements of operations (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Product development $ 23,949 $ 13,938 $ 70,064 $ 33,287 Sales and marketing 3,697 1,750 9,963 4,524 General and administrative 9,133 5,105 24,872 11,675 Total $ 36,779 $ 20,793 $ 104,899 $ 49,486 On November 17, 2015, the Company’s 2015 Employee Stock Purchase Plan (ESPP) became effective. During the three and nine months ended September 30, 2016 , the Company recorded $0.8 million and $3.8 million , respectively, of share-based compensation expense related to the ESPP, which is included in the table above. There was no similar activity during the three and nine months ended September 30, 2015 . The Company capitalized $1.2 million and $2.0 million of share-based compensation expense related to capitalized software during the three and nine months ended September 30, 2016 , respectively. There was no similar activity during the three and nine months ended September 30, 2015 . As of September 30, 2016 , there was $272.4 million of total unrecognized compensation cost related to outstanding stock options that is expected to be recognized over a weighted-average period of 2.95 years .

LOSS PER SHARE

LOSS PER SHARE	9 Months Ended
	Sep. 30, 2016
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 years 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 September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Net loss $ (32,323 ) $ (53,930 ) $ (156,423 ) $ (131,528 ) Basic shares: Weighted-average common shares outstanding 346,299 156,206 339,728 153,965 Weighted-average unvested shares (2,406 ) (3,872 ) (3,135 ) (4,907 ) Weighted-average shares used to compute basic net loss per share 343,893 152,334 336,593 149,058 Diluted shares: Weighted-average shares used to compute diluted loss per share 343,893 152,334 336,593 149,058 Net loss per share: Basic $ (0.09 ) $ (0.35 ) $ (0.46 ) $ (0.88 ) Diluted $ (0.09 ) $ (0.35 ) $ (0.46 ) $ (0.88 ) 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 and Nine Months Ended September 30, 2016 2015 Stock options and restricted stock units 101,972 106,234 Common stock warrants 9,458 9,457 Preferred stock warrants — 87 Convertible preferred stock — 135,253 Unvested shares 1,997 3,872 Employee stock purchase plan 637 — Total anti-dilutive securities 114,064 254,903

OTHER INCOME AND EXPENSE, NET

OTHER INCOME AND EXPENSE, NET	9 Months Ended
	Sep. 30, 2016
Other Income and Expenses [Abstract]
OTHER INCOME AND EXPENSE, NET	OTHER INCOME AND EXPENSE, NET Other income and expense, net, is comprised of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Net (gain) loss on foreign exchange $ 217 $ 610 $ (789 ) $ 1,324 Other 77 34 99 66 Total other (income) and expense, net $ 294 $ 644 $ (690 ) $ 1,390

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2016
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 2016 and 2025 . The Company recognized total rental expenses under operating leases of $2.9 million and $8.4 million for the three and nine months ended September 30, 2016 , respectively, compared to $3.1 million and $9.8 million for the three and nine months ended September 30, 2015 , respectively. Future minimum lease payments under non-cancelable operating leases (with initial or remaining lease terms in excess of one year) and future minimum capital lease payments as of September 30, 2016 are as follows (in thousands): Capital Operating Year: 2016 (remaining 3 months) $ 116 $ 4,017 2017 449 16,610 2018 406 16,386 2019 299 15,510 2020 — 15,590 Thereafter — 51,631 Total $ 1,270 $ 119,744 Less amount representing interest (3 ) Present value of capital lease obligations 1,267 Less current portion of capital lease obligation (458 ) Non-current portion of capital lease obligation $ 809 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 Company is involved in a class action lawsuit concerning independent contractors in connection with the Company’s Caviar business. On March 19, 2015, Jeffry Levin, on behalf of a putative nationwide class, filed a lawsuit in the United States District Court for the Northern District of California against the Company’s wholly owned subsidiary, Caviar, Inc., which, as amended, alleges that Caviar misclassified Mr. Levin and other similarly situated couriers as independent contractors and, in doing so, violated various provisions of the California Labor Code and California Business and Professions Code by requiring them to pay various business expenses that should have been borne by Caviar. The Court compelled arbitration of Mr. Levin’s individual claims on November 16, 2015 and dismissed the lawsuit in its entirety with prejudice on May 2, 2016. On June 1, 2016, Mr. Levin filed a Notice of Appeal of the Court’s order compelling arbitration with the United States Court of Appeals for the Ninth Circuit. Mr. Levin filed his opening appellate brief regarding the order compelling arbitration of his individual claims on October 7, 2016. The Company’s answering brief is due November 7, 2016. Mr. Levin also sought an award of penalties pursuant to the Labor Code Private Attorneys General Act of 2004 (PAGA). The parties stipulated that Mr. Levin would no longer pursue this PAGA claim, but this claim may instead be pursued by a different courier. In addition, from time to time, the Company is involved in various other litigation matters and disputes arising in the ordinary course of business. While it is not feasible to predict or determine the ultimate outcome of these matters, the Company believes that none of the Company's current legal proceedings will have a material adverse effect on the Company's business.

SEGMENT AND GEOGRAPHICAL INFORM

SEGMENT AND GEOGRAPHICAL INFORMATION	9 Months Ended
	Sep. 30, 2016
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 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 merchants. The following table sets forth revenue by geographic area (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Revenue United States $ 421,317 $ 320,858 $ 1,210,704 $ 863,148 International 17,685 11,330 46,100 29,610 Total net revenue $ 439,002 $ 332,188 $ 1,256,804 $ 892,758 No individual country from the international markets contributed in excess of 10% of total revenue for three and nine months ended September 30, 2016 and 2015 . Long-Lived Assets The following table sets forth long-lived assets by geographic area (in thousands): September 30, December 31, Long-lived assets United States $ 164,152 $ 168,583 International 2,756 2,114 Total long-lived assets $ 166,908 $ 170,697

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	9 Months Ended
	Sep. 30, 2016
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): Nine Months Ended September 30, 2016 2015 Supplemental Cash Flow Data: Cash paid for interest $ 428 $ 888 Cash paid for income taxes 321 1,798 Supplemental disclosures of non-cash investing and financing activities: Change in purchases of property and equipment in accounts payable and accrued expenses 1,310 4,366 Fair value of shares issued related to acquisitions — 27,456

DESCRIPTION OF BUSINESS AND S26

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2016
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, 2015 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 nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 , 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, 2015 .
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. Significant estimates, judgments, and assumptions in these consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, provision for uncollectible receivables related to merchant cash advances (MCAs), valuation of loans held for sale, business combinations, goodwill and intangible assets, income taxes, and share-based compensation.
Concentration of Credit Risk	The Company places its cash and cash equivalents and investments in marketable securities with large creditworthy U.S. financial institutions. Balances in these accounts may exceed federally insured limits at times.
Loans Held for Sale	The loans are classified as held for sale upon purchase, as it is the Company’s intent to sell all of its rights, title, and interest in these loans to third-party investors for an up-front origination fee when the loans are sold. The Company also earns a servicing fee by continuing to service the loans by remitting monies to the third-party investors. Revenue from origination fees are recognized upon transfer of title to investors and servicing revenue is recognized as servicing is delivered. A loan that is initially designated as held for sale may be reclassified to held for investment if and when the Company's intent for that loan changes. There have been no reclassifications made to date. Loans are recorded at the lower of cost or fair value. To determine the fair value of loans, the Company utilizes industry standard modeling, such as discounted cash flow models, to arrive at an estimate of fair value.
Recently Issued Accounting Standards	In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers , and issued subsequent amendments to the initial guidance within ASU 2015-04, ASU 2016-08, ASU 2016-10, and ASU 2016-12. The new guidance will replace all current U.S. GAAP guidance on this topic and eliminate all industry specific guidance. The core principal of this new guidance is that revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration for which the Company expects to be entitled in exchange for those goods or services. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted. The guidance can be applied either retrospectively to each period presented or as a cumulative effect adjustment as of the date of adoption. The Company has not yet selected a transition method and is evaluating the impact of adopting this new accounting standard update on the consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-04, Recognition of Breakage for Certain Prepaid Stored-Value Products. This guidance specifies how prepaid stored-value product liabilities should be derecognized, thereby eliminating the current and potential future diversity in practice. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, 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. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting , which is intended to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2016, 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. 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. In August 2016, the FASB issues ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments. This guidance addresses several specific cash flow issues with the objective of reducing the existing diversity in practice. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, 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.

FAIR VALUE OF FINANCIAL INSTR27

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The Company’s financial assets and liabilities that are measured at fair value on a recurring basis are classified as follows (in thousands): September 30, 2016 December 31, 2015 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash and Cash Equivalents: Money market funds $ 209,364 $ — $ — $ 337,234 $ — $ — Commercial paper — 1,500 — — — — Short-term securities: U.S. agency securities — 13,088 — — — — Corporate bonds — 19,787 — — — — Commercial paper — 17,455 — — — — Municipal securities — 6,529 — U.S. government securities 19,568 — — — — — Long-term securities: — — — U.S. agency securities — 6,519 — — — — Corporate bonds — 4,423 — — — — Municipal securities — 3,033 — — — — U.S. government securities 1,503 — — — — — Total $ 230,435 $ 72,334 $ — $ 337,234 $ — $ — A summary of loans disclosed at fair value on a recurring basis is as follows (in thousands): September 30, 2016 Carrying Value Fair Value (Level 3) Loans held for sale 28,817 29,778 Total 28,817 29,778

INVESTMENTS (Tables)

INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Short-term and Long-term Investments	The Company's short-term and long-term investments as of September 30, 2016 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term securities: U.S. agency securities $ 13,076 $ 12 $ — $ 13,088 Corporate bonds 19,795 — (8 ) 19,787 Commercial paper 17,455 — — 17,455 Municipal securities 6,530 — (1 ) 6,529 U.S. government securities 19,552 16 — 19,568 Total $ 76,408 $ 28 $ (9 ) $ 76,427 Long-term securities: U.S. agency securities $ 6,508 $ 11 $ — $ 6,519 Corporate bonds 4,419 4 — 4,423 Municipal securities 3,038 — (5 ) 3,033 U.S. government securities 1,500 3 — 1,503 Total $ 15,465 $ 18 $ (5 ) $ 15,478
Investments Classified by Contractual Maturity Date	The contractual maturities of the Company's short-term and long-term investments as of September 30, 2016 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 76,408 $ 76,427 Due in one to five years 15,465 15,478 Total $ 91,873 $ 91,905

ALLOWANCE FOR MERCHANT CASH A29

ALLOWANCE FOR MERCHANT CASH ADVANCE LOSSES (Tables)	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Schedule of Allowance for Uncollectible Merchant Cash Advance Receivables	The following table summarizes the activities of the Company’s allowance for uncollectible merchant cash advance receivables (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Allowance for uncollectible MCA receivables, beginning of the period $ 5,091 $ 5,277 $ 7,443 $ 2,431 Provision for uncollectible MCA receivables 602 1,468 509 4,616 MCA receivables charged off (855 ) (809 ) (3,114 ) (1,111 ) Allowance for uncollectible MCA receivables, end of the period $ 4,838 $ 5,936 $ 4,838 $ 5,936

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property, Equipment, and Internally Developed Software	The following is a summary of property, equipment, and internally-developed software at cost, less accumulated depreciation and amortization (in thousands): September 30, December 31, Computer equipment $ 50,520 $ 43,531 Office furniture and equipment 10,110 9,339 Leasehold improvements 72,308 65,298 Capitalized software 22,761 14,533 Construction in process 670 490 Total 156,369 133,191 Less: Accumulated depreciation and amortization (66,412 ) (45,969 ) Property and equipment, net $ 89,957 $ 87,222

ACQUIRED INTANGIBLE ASSETS (Tab

ACQUIRED INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite Lived Intangible Assets	The following table presents the detail of acquired intangible assets as of the periods presented (in thousands): Balance as of September 30, 2016 Cost Accumulated Amortization Net Patent $ 1,285 $ (427 ) $ 858 Technology Assets 29,045 (12,786 ) 16,259 Customer Assets 6,645 (3,510 ) 3,135 Total $ 36,975 $ (16,723 ) $ 20,252 Balance as of December 31, 2015 Cost Accumulated Amortization Net Patent $ 1,285 $ (348 ) $ 937 Technology Assets 28,645 (6,644 ) 22,001 Customer Assets 6,645 (2,807 ) 3,838 Total $ 36,575 $ (9,799 ) $ 26,776
Schedule of Annual Future Amortization Expense of Intangible Assets	The total estimated annual future amortization expense of these intangible assets as of September 30, 2016 is as follows (in thousands): 2016 (remaining 3 months) $ 2,048 2017 7,187 2018 5,687 2019 2,983 2020 1,087 Thereafter 1,260 Total $ 20,252

OTHER CONSOLIDATED BALANCE SH32

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) (Tables)	9 Months Ended
	Sep. 30, 2016
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): September 30, December 31, Accounts receivable $ 7,407 $ 4,808 Prepaid expenses 3,734 7,101 Deferred reader costs 3,869 4,018 Inventory 14,695 11,864 Tenant improvement reimbursement receivable 1,189 1,788 Deferred hardware costs 2,839 1,709 Processing costs receivable 4,470 7,847 Other 6,041 2,312 Total $ 44,244 $ 41,447
Schedule of Accrued Expenses	The following table presents the detail of accrued expenses (in thousands): September 30, December 31, Accrued hardware costs $ 6,345 $ 11,622 Processing costs payable 7,182 11,417 Accrued professional fees 4,247 7,642 Accrued payroll 6,712 2,660 Accrued marketing 7,147 2,443 Other accrued liabilities 10,310 8,617 Total $ 41,943 $ 44,401
Schedule of Other Current Liabilities	The following table presents the detail of other current liabilities (in thousands): September 30, December 31, Settlements payable 27,515 $ 13,105 Employee early exercised stock options 924 2,141 Accrued redemptions 1,369 1,066 Current portion of deferred rent 2,750 2,393 Deferred revenue 5,303 6,623 Other 6,639 3,617 Total $ 44,500 $ 28,945

OTHER CONSOLIDATED BALANCE SH33

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) (Tables)	9 Months Ended
	Sep. 30, 2016
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): September 30, December 31, Deposits $ 2,104 $ 1,993 Deferred tax assets 301 188 Other 1,253 1,645 Total $ 3,658 $ 3,826
Schedule of Other Non-Current Liabilities	The following table presents the detail of other non-current liabilities (in thousands): September 30, December 31, Deferred rent $ 23,790 $ 25,543 Employee early exercised stock options 201 1,128 Deferred tax liabilities 285 299 Statutory liabilities 27,554 25,492 Other 3,965 60 Total $ 55,795 $ 52,522

ACCRUED TRANSACTION LOSSES (Tab

ACCRUED TRANSACTION LOSSES (Tables)	9 Months Ended
	Sep. 30, 2016
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 September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Accrued transaction losses, beginning of the period $ 16,093 $ 15,844 $ 17,176 $ 8,452 Provision for transaction losses 13,483 11,401 36,875 32,967 Charge-offs and recoveries to accrued transaction losses (8,148 ) (11,241 ) (32,623 ) (25,415 ) Accrued transaction losses, end of the period $ 21,428 $ 16,004 $ 21,428 $ 16,004

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	A summary of stock option activity for the nine months ended September 30, 2016 is as follows (in thousands, except share and per share data): Number of Stock Options Outstanding Weighted Weighted Aggregate Balance as of December 31, 2015 107,515,554 $ 6.99 7.87 $ 656,194 Granted 1,767,320 13.49 Exercised (13,559,723 ) 3.02 Forfeited (9,020,899 ) $ 10.99 Balance as of September 30, 2016 86,702,252 7.32 7.40 418,923 Options vested and expected to vest as of September 30, 2016 81,679,340 7.10 6.81 410,515 Options exercisable as of September 30, 2016 82,443,845 7.15 7.31 411,791
Schedule of RSU Activity	Activity related to RSUs during the nine months ended September 30, 2016 is set forth below: Number of Weighted Unvested as of December 31, 2015 3,632,765 $ 13.14 Granted 14,546,288 12.12 Vested (1,780,873 ) 12.48 Forfeited (1,128,359 ) 13.09 Unvested as of September 30, 2016 15,269,821 $ 12.25
Schedule of Fair Value Assumptions for Options	The fair value of stock options granted was estimated using the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Dividend yield — % — % — % — % Risk-free interest rate 1.31 % 1.69 % 1.54 % 1.73 % Expected volatility 43.51 % 44.56 % 42.74 % 47.91 % Expected term (years) 6.08 5.86 6.08 6.06
Summary of the Effect of Share-Based Compensation on the Condensed Consolidated Statement 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 September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Product development $ 23,949 $ 13,938 $ 70,064 $ 33,287 Sales and marketing 3,697 1,750 9,963 4,524 General and administrative 9,133 5,105 24,872 11,675 Total $ 36,779 $ 20,793 $ 104,899 $ 49,486

LOSS PER SHARE (Tables)

LOSS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Net loss $ (32,323 ) $ (53,930 ) $ (156,423 ) $ (131,528 ) Basic shares: Weighted-average common shares outstanding 346,299 156,206 339,728 153,965 Weighted-average unvested shares (2,406 ) (3,872 ) (3,135 ) (4,907 ) Weighted-average shares used to compute basic net loss per share 343,893 152,334 336,593 149,058 Diluted shares: Weighted-average shares used to compute diluted loss per share 343,893 152,334 336,593 149,058 Net loss per share: Basic $ (0.09 ) $ (0.35 ) $ (0.46 ) $ (0.88 ) Diluted $ (0.09 ) $ (0.35 ) $ (0.46 ) $ (0.88 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings 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 and Nine Months Ended September 30, 2016 2015 Stock options and restricted stock units 101,972 106,234 Common stock warrants 9,458 9,457 Preferred stock warrants — 87 Convertible preferred stock — 135,253 Unvested shares 1,997 3,872 Employee stock purchase plan 637 — Total anti-dilutive securities 114,064 254,903

OTHER INCOME AND EXPENSE, NET (

OTHER INCOME AND EXPENSE, NET (Tables)	9 Months Ended
	Sep. 30, 2016
Other Income and Expenses [Abstract]
Schedule of Other Income (Expense)	Other income and expense, net, is comprised of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Net (gain) loss on foreign exchange $ 217 $ 610 $ (789 ) $ 1,324 Other 77 34 99 66 Total other (income) and expense, net $ 294 $ 644 $ (690 ) $ 1,390

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2016
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 or remaining lease terms in excess of one year) and future minimum capital lease payments as of September 30, 2016 are as follows (in thousands): Capital Operating Year: 2016 (remaining 3 months) $ 116 $ 4,017 2017 449 16,610 2018 406 16,386 2019 299 15,510 2020 — 15,590 Thereafter — 51,631 Total $ 1,270 $ 119,744 Less amount representing interest (3 ) Present value of capital lease obligations 1,267 Less current portion of capital lease obligation (458 ) Non-current portion of capital lease obligation $ 809

SEGMENT AND GEOGRAPHICAL INFO39

SEGMENT AND GEOGRAPHICAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Revenue from External Customers by Geographic Areas	Revenue by geography is based on the billing addresses of the merchants. The following table sets forth revenue by geographic area (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Revenue United States $ 421,317 $ 320,858 $ 1,210,704 $ 863,148 International 17,685 11,330 46,100 29,610 Total net revenue $ 439,002 $ 332,188 $ 1,256,804 $ 892,758
Long-lived Assets by Geographic Areas	The following table sets forth long-lived assets by geographic area (in thousands): September 30, December 31, Long-lived assets United States $ 164,152 $ 168,583 International 2,756 2,114 Total long-lived assets $ 166,908 $ 170,697

SUPPLEMENTAL CASH FLOW INFORM40

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	The supplemental disclosures of cash flow information consist of the following (in thousands): Nine Months Ended September 30, 2016 2015 Supplemental Cash Flow Data: Cash paid for interest $ 428 $ 888 Cash paid for income taxes 321 1,798 Supplemental disclosures of non-cash investing and financing activities: Change in purchases of property and equipment in accounts payable and accrued expenses 1,310 4,366 Fair value of shares issued related to acquisitions — 27,456

DESCRIPTION OF BUSINESS AND S41

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - IPO (Details) - IPO $ / shares in Units, $ in Millions	1 Months Ended
	Nov. 30, 2015USD ($)$ / sharesshares
Class of Stock [Line Items]
Proceeds from issuance initial public offering	$ 245.7
Payments of underwriting discounts and commissions	14.7
Payments of other offering expenses	$ 6.9
Class A
Class of Stock [Line Items]
Shares issued (in shares) | shares	29,700,000
Shares issued, price per share (in USD per share) | $ / shares	$ 9
Shares sold by stockholder (in shares) | shares	1,350,000

DESCRIPTION OF BUSINESS AND S42

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Out of Period Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses	$ 12,885		$ 16,005	$ 38,201	$ 40,840
Out of Period Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses		$ 6,000
Out of Period Adjustment, Related to Three Months Ended March 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses		500
Out of Period Adjustment, Related to the Year Ended December 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses		2,600
Out of Period Adjustment, Related to the Year Ended December 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses		1,600
Out of Period Adjustment, Related to the Year Ended December 31, 2013
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses		1,000
Out of Period Adjustment, Related to Historical Periods
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Transaction, loan and advance losses		$ 300

DESCRIPTION OF BUSINESS AND S43

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Litigation Settlement (Details) $ in Millions	Jun. 08, 2016USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Litigation settlement, amount	$ (50)
Payments for legal settlements	$ 48

DESCRIPTION OF BUSINESS AND S44

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016customer	Sep. 30, 2015customer	Sep. 30, 2016customerthird_party_processor	Sep. 30, 2015customer	Dec. 31, 2015third_party_processor
Total Net Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers | customer	0	1	0	1
Settlements Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Number of third party processors | third_party_processor			3		3
Settlements Receivable | Third Party Processor One | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage			47.00%		56.00%
Settlements Receivable | Third Party Processor Two | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage			39.00%		23.00%
Settlements Receivable | Third Party Processor Three | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage			11.00%		16.00%

RESTRICTED CASH (Details)

RESTRICTED CASH (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Pledged cash	$ 13,559	$ 13,537
Collateral	$ 23,137	$ 14,686

FAIR VALUE OF FINANCIAL INSTR46

FAIR VALUE OF FINANCIAL INSTRUMENTS - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	$ 76,427	$ 0
Long-term securities	15,478	0
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	230,435	337,234
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
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	19,568	0
Long-term securities	1,503	0
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	209,364	337,234
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 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	72,334	0
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	13,088	0
Long-term securities	6,519	0
Fair Value, Measurements, Recurring | Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	19,787	0
Long-term securities	4,423	0
Fair Value, Measurements, Recurring | Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	17,455	0
Fair Value, Measurements, Recurring | Level 2 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term securities	6,529
Long-term securities	3,033	0
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 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,500	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
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 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 0	$ 0

FAIR VALUE OF FINANCIAL INSTR47

FAIR VALUE OF FINANCIAL INSTRUMENTS - Loans Disclosed at Fair Value (Details) - Level 3 - Fair Value, Measurements, Recurring $ in Thousands	Sep. 30, 2016USD ($)
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, fair value	$ 28,817
Fair Value (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, fair value	$ 29,778

INVESTMENTS Available for Sale

INVESTMENTS Available for Sale Securities (Details) $ in Thousands	Sep. 30, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
Total	$ 91,873
Fair Value	91,905
Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	76,408
Gross Unrealized Gains	28
Gross Unrealized Losses	(9)
Fair Value	76,427
Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	15,465
Gross Unrealized Gains	18
Gross Unrealized Losses	(5)
Fair Value	15,478
U.S. agency securities | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	13,076
Gross Unrealized Gains	12
Gross Unrealized Losses	0
Fair Value	13,088
U.S. agency securities | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	6,508
Gross Unrealized Gains	11
Gross Unrealized Losses	0
Fair Value	6,519
Corporate bonds | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	19,795
Gross Unrealized Gains	0
Gross Unrealized Losses	(8)
Fair Value	19,787
Corporate bonds | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	4,419
Gross Unrealized Gains	4
Gross Unrealized Losses	0
Fair Value	4,423
Commercial paper | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	17,455
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	17,455
Municipal securities | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	6,530
Gross Unrealized Gains	0
Gross Unrealized Losses	(1)
Fair Value	6,529
Municipal securities | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	3,038
Gross Unrealized Gains	0
Gross Unrealized Losses	(5)
Fair Value	3,033
U.S. government securities | Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	19,552
Gross Unrealized Gains	16
Gross Unrealized Losses	0
Fair Value	19,568
U.S. government securities | Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Total	1,500
Gross Unrealized Gains	3
Gross Unrealized Losses	0
Fair Value	$ 1,503

INVESTMENTS - Maturity of Avai

INVESTMENTS - Maturity of Available for Sale Securities (Details) $ in Thousands	Sep. 30, 2016USD ($)
Amortized Cost
Due in one year or less	$ 76,408
Due in one to five years	15,465
Total	91,873
Fair Value
Due in one year or less	76,427
Due in one to five years	15,478
Total	$ 91,905

ALLOWANCE FOR MERCHANT CASH A50

ALLOWANCE FOR MERCHANT CASH ADVANCE LOSSES - Allowance for Uncollectible Merchant Cash Advance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for uncollectible MCA receivables, beginning of the period	$ 5,091	$ 5,277	$ 7,443	$ 2,431
Provision for uncollectible MCA receivables	602	1,468	509	4,616
MCA receivables charged off	(855)	(809)	(3,114)	(1,111)
Allowance for uncollectible MCA receivables, end of the period	$ 4,838	$ 5,936	$ 4,838	$ 5,936

PROPERTY AND EQUIPMENT, NET (De

PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 156,369		$ 156,369		$ 133,191
Less: Accumulated depreciation and amortization	(66,412)		(66,412)		(45,969)
Property and equipment, net	89,957		89,957		87,222
Depreciation	7,600	$ 5,000	20,900	$ 14,200
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	50,520		50,520		43,531
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,110		10,110		9,339
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	72,308		72,308		65,298
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	22,761		22,761		14,533
Construction in process
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 670		$ 670		$ 490

GOODWILL (Details)

GOODWILL (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 56,699,000		$ 56,699,000		$ 56,699,000
Goodwill, impairment charges	$ 0	$ 0	$ 0	$ 0

ACQUIRED INTANGIBLE ASSETS - S

ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 36,975	$ 36,575
Accumulated Amortization	(16,723)	(9,799)
Net	20,252	26,776
Patent
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	1,285	1,285
Accumulated Amortization	(427)	(348)
Net	858	937
Technology Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	29,045	28,645
Accumulated Amortization	(12,786)	(6,644)
Net	16,259	22,001
Customer Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	6,645	6,645
Accumulated Amortization	(3,510)	(2,807)
Net	$ 3,135	$ 3,838

ACQUIRED INTANGIBLE ASSETS - N

ACQUIRED INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 2.1	$ 1.6	$ 6.9	$ 4.3
Weighted Average | Patent
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period			13 years
Weighted Average | Technology Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period			3 years
Weighted Average | Customer Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period			6 years

ACQUIRED INTANGIBLE ASSETS - F

ACQUIRED INTANGIBLE ASSETS - Future Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2016 (remaining 3 months)	$ 2,048
2,017	7,187
2,018	5,687
2,019	2,983
2,020	1,087
Thereafter	1,260
Net	$ 20,252	$ 26,776

OTHER CONSOLIDATED BALANCE SH56

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts receivable	$ 7,407	$ 4,808
Prepaid expenses	3,734	7,101
Deferred reader costs	3,869	4,018
Inventory	14,695	11,864
Tenant improvement reimbursement receivable	1,189	1,788
Deferred hardware costs	2,839	1,709
Processing costs receivable	4,470	7,847
Other	6,041	2,312
Total	$ 44,244	$ 41,447

OTHER CONSOLIDATED BALANCE SH57

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued hardware costs	$ 6,345	$ 11,622
Processing costs payable	7,182	11,417
Accrued professional fees	4,247	7,642
Accrued payroll	6,712	2,660
Accrued marketing	7,147	2,443
Other accrued liabilities	10,310	8,617
Total	$ 41,943	$ 44,401

OTHER CONSOLIDATED BALANCE SH58

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Settlements payable	$ 27,515	$ 13,105
Employee early exercised stock options	924	2,141
Accrued redemptions	1,369	1,066
Current portion of deferred rent	2,750	2,393
Deferred revenue	5,303	6,623
Other	6,639	3,617
Total	$ 44,500	$ 28,945

OTHER CONSOLIDATED BALANCE SH59

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) - Other Non-Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deposits	$ 2,104	$ 1,993
Deferred tax assets	301
Deferred tax assets		188
Other	1,253	1,645
Total	$ 3,658	$ 3,826

OTHER CONSOLIDATED BALANCE SH60

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred rent	$ 23,790	$ 25,543
Employee early exercised stock options	201	1,128
Deferred tax liabilities	285
Deferred tax liabilities		299
Statutory liabilities	27,554	25,492
Other	3,965	60
Total	$ 55,795	$ 52,522

DEBT (Details)

DEBT (Details) - Revolving Credit Facility - Line of Credit - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Nov. 30, 2015
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 375,000,000
Administrative agent fee	$ 100,000	$ 100,000
Unused commitment fee percentage		0.15%
Remaining borrowing capacity	375,000,000	$ 375,000,000
Unused commitment fees	$ 100,000	$ 400,000
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 | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%

ACCRUED TRANSACTION LOSSES (Det

ACCRUED TRANSACTION LOSSES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Loss Contingency Accrual
Accrued transaction losses, beginning of the period			$ 17,176
Provision for transaction losses			36,875	$ 32,967
Accrued transaction losses, end of the period	$ 21,428		21,428
Transaction Losses
Loss Contingency Accrual
Accrued transaction losses, beginning of the period	16,093	$ 15,844	17,176	8,452
Provision for transaction losses	13,483	11,401	36,875	32,967
Charge-offs and recoveries to accrued transaction losses	(8,148)	(11,241)	(32,623)	(25,415)
Accrued transaction losses, end of the period	$ 21,428	$ 16,004	$ 21,428	$ 16,004

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income tax expense	$ 230	$ 932	$ 881	$ 2,502
Effective tax rate	(0.70%)	(1.80%)	(0.60%)	(1.90%)

STOCKHOLDERS' EQUITY - Common

STOCKHOLDERS' EQUITY - Common Stock Narrative (Details) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
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)	162,988,864	31,717,133
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)	188,328,922	303,232,312

STOCKHOLDERS' EQUITY - Share B

STOCKHOLDERS' EQUITY - Share Based Compensation Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)shares	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)planshares	Sep. 30, 2015USD ($)	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 | $	$ 36,779,000	$ 20,793,000	$ 104,899,000	$ 49,486,000
Capitalized share-based compensation expense | $	1,200,000	0	2,000,000	0
Unrecognized compensation cost, options | $	272,400,000		$ 272,400,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum service requirement for affected employees			2 years
Expiration period from termination			3 years
Expiration period following initial public offering			1 year
Plan modification, incremental compensation cost | $	600,000		$ 2,000,000
Plan modification, incremental compensation cost not yet recognized | $	5,200,000		$ 5,200,000
Unrecognized compensation cost, period for recognition			2 years 11 months 12 days
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, compensation expense | $	$ 800,000	$ 0	$ 3,800,000	$ 0
2015 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (in shares) | shares					30,000,000
Shares reserved for future issuance, percentage of annual increase			5.00%
Shares available for future issuance (in shares) | shares	35,373,551		35,373,551
2015 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) | shares	19,037,766		19,037,766
2015 Stock Option Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance, amount of annual increase (in shares) | shares	40,000,000		40,000,000
2009 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares) | shares					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) | shares	82,934,307		82,934,307

STOCKHOLDERS' EQUITY - Stock O

STOCKHOLDERS' EQUITY - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2016
Number of Stock Options Outstanding
Beginning balance (in shares)			107,515,554
Granted (in shares)			1,767,320
Exercised (in shares)			(13,559,723)
Forfeited (in shares)			(9,020,899)
Ending balance (in shares)	86,702,252	107,515,554	86,702,252
Weighted Average Exercise Price
Beginning balance (in USD per share)			$ 6.99
Granted (in USD per share)			13.49
Exercised (in USD per share)			3.02
Forfeited (in USD per share)			10.99
Ending balance (in USD per share)	$ 7.32	$ 6.99	$ 6.99
Options Vested and Expected to Vest
Options vested and expected to vest (in shares)	81,679,340
Options vested and expected to vest (in USD per share)	$ 7.10
Options Exercisable
Options exercisable (in shares)	82,443,845
Options exercisable (in USD per share)	$ 7.15
Additional Disclosures
Weighted average remaining contractual term, options outstanding	7 years 4 months 24 days	7 years 10 months 13 days
Weighted average remaining contractual term, options vested and expected to vest	6 years 9 months 22 days
Weighted average remaining contractual term, options exercisable	7 years 3 months 22 days
Aggregate intrinsic value, options outstanding	$ 418,923	$ 656,194
Aggregate intrinsic value, options vested and expected to vest	410,515
Aggregate intrinsic value, options exercisable	$ 411,791

STOCKHOLDERS' EQUITY - RSU Act

STOCKHOLDERS' EQUITY - RSU Activity (Details) - RSUs	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Number of RSUs
Beginning balance (in shares) | shares	3,632,765
Granted (in shares) | shares	14,546,288
Vested (in shares) | shares	(1,780,873)
Forfeited (in shares) | shares	(1,128,359)
Ending balance (in shares) | shares	15,269,821
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share) | $ / shares	$ 13.14
Granted (in USD per share) | $ / shares	12.12
Vested (in USD per share) | $ / shares	12.48
Forfeited (in USD per share) | $ / shares	13.09
Ending balance (in USD per share) | $ / shares	$ 12.25

STOCKHOLDERS' EQUITY - Stock68

STOCKHOLDERS' EQUITY - Stock Option Fair Value Assumptions (Details) - Stock Options	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
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	1.31%	1.69%	1.54%	1.73%
Expected volatility	43.51%	44.56%	42.74%	47.91%
Expected term (years)	6 years 29 days	5 years 10 months 10 days	6 years 29 days	6 years 22 days

STOCKHOLDERS' EQUITY - Effects

STOCKHOLDERS' EQUITY - Effects of Share-Based Compensation on Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 36,779	$ 20,793	$ 104,899	$ 49,486
Product development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	23,949	13,938	70,064	33,287
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	3,697	1,750	9,963	4,524
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 9,133	$ 5,105	$ 24,872	$ 11,675

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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net loss	$ (32,323)	$ (53,930)	$ (156,423)	$ (131,528)
Basic shares:
Weighted-average common shares outstanding (in shares)	346,299	156,206	339,728	153,965
Weighted-average unvested shares (in shares)	(2,406)	(3,872)	(3,135)	(4,907)
Weighted-average shares used to compute basic net loss per share (in shares)	343,893	152,334	336,593	149,058
Diluted shares:
Weighted-average shares used to compute diluted loss per share (in shares)	343,893	152,334	336,593	149,058
Net loss per share:
Basic (in USD per share)	$ (0.09)	$ (0.35)	$ (0.46)	$ (0.88)
Diluted (in USD per share)	$ (0.09)	$ (0.35)	$ (0.46)	$ (0.88)

LOSS PER SHARE - Antidilutive

LOSS PER SHARE - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	114,064	254,903	114,064	254,903
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)	101,972	106,234	101,972	106,234
Warrants | Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	9,458	9,457	9,458	9,457
Warrants | Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	87	0	87
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	135,253	0	135,253
Unvested shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,997	3,872	1,997	3,872
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)	637	0	637	0

OTHER INCOME AND EXPENSE, NET

OTHER INCOME AND EXPENSE, NET - Other Income and Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other Income and Expenses [Abstract]
Net (gain) loss on foreign exchange	$ 217	$ 610	$ (789)	$ 1,324
Other	77	34	99	66
Total other (income) and expense, net	$ 294	$ 644	$ (690)	$ 1,390

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES - Operating and Capital Leases- Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Operating leases, rent expense	$ 2.9	$ 3.1	$ 8.4	$ 9.8

COMMITMENTS AND CONTINGENCIES74

COMMITMENTS AND CONTINGENCIES - Schedule of Future Payments Under Operating and Capital Leases (Details) $ in Thousands	Sep. 30, 2016USD ($)
Capital
2016 (remaining 3 months)	$ 116
2,017	449
2,018	406
2,019	299
2,020	0
Thereafter	0
Total	1,270
Less amount representing interest	(3)
Present value of capital lease obligations	1,267
Less current portion of capital lease obligation	(458)
Non-current portion of capital lease obligation	809
Operating
2016 (remaining 3 months)	4,017
2,017	16,610
2,018	16,386
2,019	15,510
2,020	15,590
Thereafter	51,631
Total	$ 119,744

SEGMENT AND GEOGRAPHICAL INFO75

SEGMENT AND GEOGRAPHICAL INFORMATION - Narrative (Details)	9 Months Ended
	Sep. 30, 2016segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

SEGMENT AND GEOGRAPHICAL INFO76

SEGMENT AND GEOGRAPHICAL INFORMATION - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 439,002	$ 332,188	$ 1,256,804	$ 892,758
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	421,317	320,858	1,210,704	863,148
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 17,685	$ 11,330	$ 46,100	$ 29,610

SEGMENT AND GEOGRAPHICAL INFO77

SEGMENT AND GEOGRAPHICAL INFORMATION - Long-lived Assets by Geography (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 166,908	$ 170,697
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	164,152	168,583
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 2,756	$ 2,114

SUPPLEMENTAL CASH FLOW INFORM78

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Supplemental Cash Flow Data:
Cash paid for interest	$ 428	$ 888
Cash paid for income taxes	321	1,798
Supplemental disclosures of non-cash investing and financing activities:
Change in purchases of property and equipment in accounts payable and accrued expenses	1,310	4,366
Fair value of shares issued related to acquisitions	$ 0	$ 27,456