Block (SQ) 10-Q 6 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Nov. 01, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-37622
Entity Registrant Name	Square, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	80-0429876
Entity Address, Address Line One	1455 Market Street
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94103
City Area Code	415
Local Phone Number	375-3176
Title of 12(b) Security	Class A common stock, $0.0000001 par value per share
Trading Symbol	SQ
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Class of Stock [Line Items]
Entity Central Index Key	0001512673
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		347,159,861
Class B
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		82,521,616

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 612,048	$ 583,173
Short-term investments	557,656	540,991
Restricted cash	27,389	33,838
Settlements receivable	564,492	364,946
Customer funds	660,599	334,017
Loans held for sale	120,776	89,974
Other current assets	215,806	164,966
Total current assets	2,758,766	2,111,905
Property and equipment, net	134,034	142,402
Goodwill	265,974	261,705
Acquired intangible assets, net	72,793	77,102
Long-term investments	564,508	464,680
Restricted cash	14,433	15,836
Built-to-suit lease asset	0	149,000
Operating lease right-of-use assets	108,670
Other non-current assets	81,326	58,393
Total assets	4,000,504	3,281,023
Current liabilities:
Customers payable	1,268,034	749,215
Settlements payable	81,597	54,137
Accrued transaction losses	37,419	33,682
Accrued expenses	124,005	82,354
Operating lease liabilities, current	25,779	0
Other current liabilities	108,067	99,153
Total current liabilities	1,644,901	1,018,541
Long-term debt, net of current portion (Note 13)	928,869	899,695
Built-to-suit lease liability	0	149,000
Operating lease liabilities, non-current	106,457
Other non-current liabilities	70,483	93,286
Total liabilities	2,750,710	2,160,522
Commitments and contingencies (Note 19)
Stockholders’ equity:
Preferred stock, $0.0000001 par value: 100,000,000 shares authorized at September 30, 2019 and December 31, 2018. None issued and outstanding at September 30, 2019 and December 31, 2018.	0	0
Additional paid-in capital	2,153,449	2,012,328
Accumulated other comprehensive loss	(2,387)	(6,053)
Accumulated deficit	(901,268)	(885,774)
Total stockholders’ equity	1,249,794	1,120,501
Total liabilities and stockholders’ equity	4,000,504	3,281,023
Class A
Stockholders’ equity:
Common stock	0	0
Class B
Stockholders’ equity:
Common stock	$ 0	$ 0

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
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)	346,552,092	323,546,864
Common stock, shares outstanding (in shares)	346,552,092	323,546,864
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)	82,521,716	93,501,142
Common stock, shares outstanding (in shares)	82,521,716	93,501,142

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue:
Revenue	$ 1,266,474	$ 882,108	$ 3,400,071	$ 2,365,649
Cost of revenue:
Total cost of revenue	766,437	529,448	2,037,435	1,442,003
Gross profit	500,037	352,660	1,362,636	923,646
Operating expenses:
Product development	168,771	135,773	497,322	355,668
Sales and marketing	149,467	116,337	439,601	291,846
General and administrative	115,980	85,527	318,086	243,800
Transaction, loan and advance losses	32,722	23,596	94,827	63,603
Amortization of acquired customer assets	1,003	1,294	3,591	2,235
Total operating expenses	467,943	362,527	1,353,427	957,152
Operating income (loss)	32,094	(9,867)	9,209	(33,506)
Interest expense, net	5,632	7,224	15,456	12,806
Other expense (income), net	(5,541)	(37,800)	6,988	(37,908)
Income (loss) before income tax	32,003	20,709	(13,235)	(8,404)
Provision for income taxes	2,606	1,066	2,259	1,845
Net income (loss)	$ 29,397	$ 19,643	$ (15,494)	$ (10,249)
Net income (loss) per share:
Basic (in USD per share)	$ 0.07	$ 0.05	$ (0.04)	$ (0.03)
Diluted (in USD per share)	$ 0.06	$ 0.04	$ (0.04)	$ (0.03)
Weighted-average shares used to compute net income (loss) per share
Basic (in shares)	427,124	409,690	423,239	402,980
Diluted (in shares)	466,099	474,915	423,239	402,980
Technology assets
Cost of revenue:
Amortization of acquired technology	$ 1,934	$ 2,277	$ 5,029	$ 5,714
Transaction-based revenue
Revenue:
Revenue	816,622	655,384	2,248,894	1,803,649
Cost of revenue:
Cost of revenue	519,312	414,456	1,418,730	1,137,716
Subscription and services-based revenue
Revenue:
Revenue	239,895	141,752	645,588	330,637
Revenue	279,801	166,203	750,041	397,589
Cost of revenue:
Cost of revenue	63,352	47,078	183,994	117,230
Hardware revenue
Revenue:
Revenue	21,766	17,558	62,238	50,337
Cost of revenue:
Cost of revenue	35,672	23,229	95,881	68,467
Bitcoin revenue
Revenue:
Revenue	148,285	42,963	338,898	114,074
Cost of revenue:
Cost of revenue	$ 146,167	$ 42,408	$ 333,801	$ 112,876

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 29,397	$ 19,643	$ (15,494)	$ (10,249)
Net foreign currency translation adjustments	(2,812)	(946)	(2,285)	(3,341)
Net unrealized gain (loss) on revaluation of intercompany loans	0	(296)	75	(89)
Net unrealized gain (loss) on marketable debt securities, net of tax	1,351	(647)	5,876	(1,597)
Total comprehensive income (loss)	$ 27,936	$ 17,754	$ (11,828)	$ (15,276)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ 29,397	$ (38,151)	$ 19,643	$ (23,986)	$ (15,494)	$ (10,249)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization					56,879	38,323
Non-cash interest and other expense					25,486	23,554
Loss on extinguishment of long-term debt					0	1,625
Share-based compensation					217,980	157,856
Replacement stock awards issued in connection with acquisition					0	899
Loss (gain) on revaluation of equity investment	(2,500)				16,467	(36,908)
Amortization of operating lease right-of-use assets and accretion of operating lease liabilities					21,950
Recovery of common stock in connection with indemnification settlement agreement					(789)	(2,745)
Transaction, loan and advance losses					94,827	63,603
Change in deferred income taxes					(1,054)	(563)
Changes in operating assets and liabilities:
Settlements receivable					(215,594)	(579,769)
Customer funds					(202,718)	(156,162)
Purchase of loans held for sale					(1,596,394)	(1,139,142)
Sales and principal payments of loans held for sale					1,547,158	1,130,378
Customers payable					519,123	581,530
Settlements payable					27,460	88,486
Charge-offs to accrued transaction losses					(56,486)	(40,354)
Other assets and liabilities					(34,218)	(1,702)
Net cash provided by operating activities					404,583	118,660
Cash flows from investing activities:
Purchase of marketable debt securities					(758,969)	(859,060)
Proceeds from maturities of marketable debt securities					325,682	128,603
Proceeds from sale of marketable debt securities					327,247	106,358
Purchase of marketable debt securities from customer funds					(237,640)	0
Proceeds from maturities of marketable debt securities from customer funds					115,200	0
Purchase of property and equipment					(45,826)	(37,173)
Payments for other investments					(2,000)	0
Purchase of intangible assets					0	(1,584)
Business combinations, net of cash acquired					(20,372)	(112,399)
Net cash used in investing activities					(296,678)	(775,255)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes, net					0	855,663
Purchase of convertible senior note hedges					0	(172,586)
Proceeds from issuance of warrants					0	112,125
Principal payment on conversion of senior notes					0	(70,047)
Payments for tax withholding related to vesting of restricted stock units					(164,044)	(125,899)
Proceeds from the exercise of stock options, net					81,781	94,780
Other financing activities					(3,946)	(3,298)
Net cash provided by (used in) financing activities					(86,209)	690,738
Effect of foreign exchange rate on cash and cash equivalents					(673)	(4,154)
Net increase in cash, cash equivalents and restricted cash					21,023	29,989
Cash, cash equivalents and restricted cash, beginning of period		$ 632,847		$ 735,081	632,847	735,081	$ 735,081
Cash, cash equivalents and restricted cash, end of period	$ 653,870		$ 765,070		$ 653,870	$ 765,070	$ 632,847

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Class A and B common stock	Additional paid-in capital	Accumulated other comprehensive loss	Accumulated deficit
Beginning balance (in shares) at Dec. 31, 2017		395,194,075
Beginning balance at Dec. 31, 2017	$ 786,333	$ 0	$ 1,630,386	$ (1,318)	$ (842,735)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(23,986)				(23,986)
Shares issued in connection with:
Exercise of stock options (in shares)		4,213,775
Exercise of stock options	31,354		31,354
Vesting of early exercised stock options and other	136		136
Vesting of restricted stock units (in shares)		1,625,534
Change in other comprehensive loss	24			24
Share-based compensation	48,356		48,356
Tax withholding related to vesting of restricted stock units (in shares)		(649,305)
Tax withholding related to vesting of restricted stock units	(27,651)		(27,651)
Ending balance (in shares) at Mar. 31, 2018		400,384,079
Ending balance at Mar. 31, 2018	809,980	$ 0	1,682,581	(1,294)	(871,307)
Beginning balance (in shares) at Dec. 31, 2017		395,194,075
Beginning balance at Dec. 31, 2017	786,333	$ 0	1,630,386	(1,318)	(842,735)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(10,249)
Ending balance (in shares) at Sep. 30, 2018		412,372,832
Ending balance at Sep. 30, 2018	1,122,144	$ 0	1,986,059	(6,345)	(857,570)
Beginning balance (in shares) at Mar. 31, 2018		400,384,079
Beginning balance at Mar. 31, 2018	809,980	$ 0	1,682,581	(1,294)	(871,307)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(5,906)				(5,906)
Shares issued in connection with:
Exercise of stock options (in shares)		3,246,683
Exercise of stock options	23,267		23,267
Vesting of early exercised stock options and other	19		19
Purchases under employee stock purchase plan (in shares)		450,236
Purchases under employee stock purchase plan	12,578		12,578
Vesting of restricted stock units (in shares)		2,385,704
Issuance of common stock in connection with business combination (in shares)		2,658,139
Issuance of common stock in connection with business combination	140,154		140,154
Change in other comprehensive loss	(3,162)			(3,162)
Share-based compensation	54,810		54,810
Tax withholding related to vesting of restricted stock units (in shares)		(773,120)
Tax withholding related to vesting of restricted stock units	(40,924)		(40,924)
Conversion feature of convertible senior notes, due 2023, net of allocated costs	154,019		154,019
Purchase of bond hedges in conjunction with issuance of convertible senior notes, due 2023	(172,586)		(172,586)
Sale of warrants in conjunction with issuance of convertible senior notes, due 2023	112,125		112,125
Recovery of common stock in connection with indemnification settlement agreement (in shares)		(469,898)
Recovery of common stock in connection with indemnification settlement agreement	(2,745)		(2,745)
Ending balance (in shares) at Jun. 30, 2018		407,881,823
Ending balance at Jun. 30, 2018	1,081,629	$ 0	1,963,298	(4,456)	(877,213)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	19,643				19,643
Shares issued in connection with:
Exercise of stock options (in shares)		3,200,992
Exercise of stock options	27,580		27,580
Vesting of early exercised stock options and other (in shares)		347
Vesting of early exercised stock options and other	12		12
Vesting of restricted stock units (in shares)		2,088,191
Issuance of common stock in connection with business combination (in shares)		1,542
Issuance of common stock in connection with business combination	853		853
Change in other comprehensive loss	(1,889)			(1,889)
Share-based compensation	60,945		60,945
Tax withholding related to vesting of restricted stock units (in shares)		(800,065)
Tax withholding related to vesting of restricted stock units	(57,324)		(57,324)
Issuance of common stock in conjunction with the conversion of senior notes, due 2022 (in shares)		2,161,631
Issuance of common stock in conjunction with the conversion of senior notes, due 2022	(9,305)		(9,305)
Exercise of bond hedges in conjunction with the conversion of senior notes, due 2022 (in shares)		(2,161,629)
Ending balance (in shares) at Sep. 30, 2018		412,372,832
Ending balance at Sep. 30, 2018	1,122,144	$ 0	1,986,059	(6,345)	(857,570)
Beginning balance (in shares) at Dec. 31, 2018		417,048,006
Beginning balance at Dec. 31, 2018	1,120,501	$ 0	2,012,328	(6,053)	(885,774)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(38,151)				(38,151)
Shares issued in connection with:
Exercise of stock options (in shares)		3,588,052
Exercise of stock options	25,328		25,328
Vesting of early exercised stock options and other (in shares)		425
Vesting of early exercised stock options and other	36		36
Vesting of restricted stock units (in shares)		1,994,156
Change in other comprehensive loss	2,629			2,629
Share-based compensation	62,835		62,835
Tax withholding related to vesting of restricted stock units (in shares)		(741,324)
Tax withholding related to vesting of restricted stock units	(50,801)		(50,801)
Issuance of common stock in conjunction with the conversion of senior notes, due 2022 (in shares)		43
Issuance of common stock in conjunction with the conversion of senior notes, due 2022	1		1
Exercise of bond hedges in conjunction with the conversion of senior notes, due 2022 (in shares)		(250,614)
Recovery of common stock in connection with indemnification settlement agreement (in shares)		(14,798)
Recovery of common stock in connection with indemnification settlement agreement	(789)		(789)
Ending balance (in shares) at Mar. 31, 2019		421,623,946
Ending balance at Mar. 31, 2019	1,121,589	$ 0	2,048,938	(3,424)	(923,925)
Beginning balance (in shares) at Dec. 31, 2018		417,048,006
Beginning balance at Dec. 31, 2018	1,120,501	$ 0	2,012,328	(6,053)	(885,774)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (15,494)
Shares issued in connection with:
Exercise of stock options (in shares)	7,881,289
Ending balance (in shares) at Sep. 30, 2019		429,073,808
Ending balance at Sep. 30, 2019	$ 1,249,794	$ 0	2,153,449	(2,387)	(901,268)
Beginning balance (in shares) at Mar. 31, 2019		421,623,946
Beginning balance at Mar. 31, 2019	1,121,589	$ 0	2,048,938	(3,424)	(923,925)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(6,740)				(6,740)
Shares issued in connection with:
Exercise of stock options (in shares)		2,671,530
Exercise of stock options	22,651		22,651
Purchases under employee stock purchase plan (in shares)		360,328
Purchases under employee stock purchase plan	18,942		18,942
Vesting of restricted stock units (in shares)		2,339,193
Change in other comprehensive loss	2,498			2,498
Share-based compensation	81,392		81,392
Tax withholding related to vesting of restricted stock units (in shares)		(777,006)
Tax withholding related to vesting of restricted stock units	(55,862)		(55,862)
Issuance of common stock in conjunction with the conversion of senior notes, due 2022 (in shares)		86
Issuance of common stock in conjunction with the conversion of senior notes, due 2022	2		2
Exercise of bond hedges in conjunction with the conversion of senior notes, due 2022 (in shares)		(84)
Ending balance (in shares) at Jun. 30, 2019		426,217,993
Ending balance at Jun. 30, 2019	1,184,472	$ 0	2,116,063	(926)	(930,665)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	29,397				29,397
Shares issued in connection with:
Exercise of stock options (in shares)		1,621,707
Exercise of stock options	14,860		14,860
Vesting of restricted stock units (in shares)		2,035,852
Change in other comprehensive loss	(1,461)			(1,461)
Share-based compensation	79,907		79,907
Tax withholding related to vesting of restricted stock units (in shares)		(801,744)
Tax withholding related to vesting of restricted stock units	(57,381)		(57,381)
Ending balance (in shares) at Sep. 30, 2019		429,073,808
Ending balance at Sep. 30, 2019	$ 1,249,794	$ 0	$ 2,153,449	$ (2,387)	$ (901,268)

DESCRIPTION OF BUSINESS AND SUM

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Business Square, Inc. (together with its subsidiaries, Square or the Company) creates tools that empower businesses, sellers and individuals to participate in the economy. Square enables sellers to accept card payments and also provides reporting and analytics, and next-day settlement. Square’s point-of-sale software and other business services help sellers manage inventory, locations, and employees; access financing; engage buyers; build a website or online store; and grow sales. Cash App is an easy way to send, spend, and store money. In July 2019, the Company entered into a definitive agreement to sell the Caviar business, a food ordering service, which closed on October 31, 2019. Square was founded in 2009 and is headquartered in San Francisco, with offices in the United States, Canada, Japan, Australia, Ireland, and the UK. Basis of Presentation The accompanying interim condensed consolidated financial statements of the Company are unaudited. These interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) and the applicable rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The December 31, 2018 condensed consolidated balance sheet was derived from the audited financial statements as of that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The accompanying unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company's consolidated financial position, results of operations, comprehensive income (loss), and cash flows for the interim periods. All intercompany transactions and balances have been eliminated in consolidation. The interim results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 , or for any other future annual or interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Consolidated Financial Statements and related notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 . Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, as well as related disclosure of contingent assets and liabilities. Actual results could differ from the Company’s estimates. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be materially affected. The Company bases its estimates on past experience and other assumptions that the Company believes are reasonable under the circumstances, and the Company evaluates these estimates on an ongoing basis. Estimates, judgments, and assumptions in these consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, valuation of the debt component of convertible senior notes, valuation of loans held for sale, goodwill, acquired intangible assets and deferred revenue, income and other taxes, operating and financing lease right-of-use assets and related liabilities, and share-based compensation. Concentration of Credit Risk For the three and nine months ended September 30, 2019 and 2018 , the Company had no customer that accounted for greater than 10% of total net revenue. The Company had three third-party payment processors that represented approximately 46% , 34% , and 9% of settlements receivable as of September 30, 2019 . The same three parties represented approximately 45% , 33% , and 9% of settlements receivable as of December 31, 2018 . All other third-party processors were insignificant. Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, marketable debt securities, settlements receivables, customer funds, and loans held for sale. The associated risk of concentration for cash and cash equivalents and restricted cash is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed federal deposit insurance limits. The associated risk of concentration for marketable debt securities is mitigated by holding a diversified portfolio of highly rated investments. Settlements receivable are amounts due from well-established payment processing companies and normally take one or two business days to settle which mitigates the associated risk of concentration. The associated risk of concentration for loans held for sale is partially mitigated by credit evaluations that are performed prior to facilitating the offering of loans and ongoing performance monitoring of the Company’s loan customers. Assets Held for Sale The Company classifies an asset group (‘asset’) as held for sale in the period that (i) it has approved and committed to a plan to sell the asset, (ii) the asset is available for immediate sale in its present condition, (iii) an active program to locate a buyer and other actions required to sell the asset have been initiated, (iv) the sale of the asset is probable and transfer of the asset is expected to qualify for recognition as a completed sale within one year (subject to certain events or circumstances), (v) the asset is being actively marketed for sale at a price that is reasonable in relation to its current fair value, and (vi) it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. The Company initially and subsequently measures a long-lived asset that is classified as held for sale at the lower of its carrying value or fair value less any costs to sell. Any loss resulting from this measurement is recognized in general and administrative expenses in the period in which the held for sale criteria are met. Conversely, gains are generally not recognized on the sale of a long-lived asset until the date of sale. Upon designation as an asset held for sale, the Company stops recording depreciation or amortization expense on the asset. The Company assesses the fair value of assets held for sale less any costs to sell at each reporting period until the asset is no longer classified as held for sale. New Accounting Policies The Company adopted Accounting Standards Codification (ASC) 842, Leases on January 1, 2019, and elected the optional transition method to apply the transition provisions from the effective date of adoption, which requires the Company to report the cumulative effect of the adoption of the standard on the date of adoption with no changes to the prior period balances. Pursuant to the practical expedients, the Company has elected not to reassess: (i) whether expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases, or, (iii) initial direct costs for any existing leases. The Company recognized $112.0 million of operating right-of-use lease assets and $135.6 million of operating lease liabilities on its consolidated balance sheet upon adoption of this standard. Additionally, the Company derecognized $149 million related to the build-to-suit asset and liability upon adoption of this standard because the Company is no longer deemed to be the owner of the related asset under construction under the new standard. Refer to Note 19 for further detail. Except for the adoption of ASC 842, there have been no material changes to the Company’s accounting policies during the nine months ended September 30, 2019 , as compared to the accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 . Recent Accounting Pronouncements Recently issued accounting pronouncements not yet adopted In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-13,Financial Instruments - Credit Losses, which requires the measurement and recognition of expected credit losses for financial assets held. It also eliminates the concept of other-than-temporary impairment and requires credit losses related to available for sale debt securities to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company intends to adopt this guidance effective January 1, 2020. The Company’s preliminary conclusion is that the new guidance will not have a material impact on the balances reported on its consolidated financial statements. The Company has also determined that allowances for credit losses associated with its available for sale debt securities would be immaterial. Upon adoption of this guidance, the Company will expand its disclosures to discuss how it develops its expected credit loss estimates, the methodology applied to estimate the allowance for credit losses, and the factors that influence the Company's estimates. For available for sale debt securities with unrealized losses where the Company concludes that an allowance for credit losses is not necessary, the Company will expand its disclosures of the associated fair value of such securities as well as the basis for conclusions that an allowance for credit losses was not necessary. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment . The new guidance eliminates the requirement to calculate the implied fair value of goodwill assuming a hypothetical purchase price allocation (i.e., Step 2 of the goodwill impairment test) to measure a goodwill impairment charge. Instead, entities will record an impairment charge based on the excess of a reporting unit’s carrying amount over its fair value, not to exceed the carrying amount of goodwill. This standard should be adopted when the Company performs its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted. The amendments should be applied on a prospective basis. The Company intends to adopt this guidance effective with its 2019 annual goodwill impairment test which it performs as of December 31. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures. In July 2018, the FASB issued ASU 2018-13, Changes to the Disclosure Requirements for Fair Value Measurement, which will remove, modify, and add disclosure requirements for fair value measurements to improve the overall usefulness of such disclosures. 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 for any removed or modified disclosure requirements. Transition is on a prospective basis for the new and modified disclosures, and on a retrospective basis for disclosures that have been eliminated. The Company currently does not intend to early adopt any portion of this disclosure guidance. The Company is currently evaluating the impact this guidance may have on the consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which is intended to align the requirements for capitalization of implementation costs incurred in a cloud computing arrangement that is a service contract with the existing guidance for internal-use software. 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 guidance provides flexibility in adoption, allowing for either retrospective adjustment or prospective adjustment for all implementation costs incurred after the date of adoption. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures.

REVENUE

REVENUE	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE The following table presents the Company's revenue disaggregated by revenue source (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenue from Contracts with Customers: Transaction-based revenue $ 816,622 $ 655,384 $ 2,248,894 $ 1,803,649 Subscription and services-based revenue 239,895 141,752 645,588 330,637 Hardware revenue 21,766 17,558 62,238 50,337 Bitcoin revenue 148,285 42,963 338,898 114,074 Revenue from other sources: Subscription and services-based revenue $ 39,906 $ 24,451 $ 104,453 $ 66,952 The deferred revenue balances were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Deferred revenue, beginning of the period $ 44,812 $ 27,155 $ 36,451 $ 5,893 Less: cumulative impact of the adoption of ASC 606 — — — (4,303 ) Deferred revenue, beginning of the period, as adjusted 44,812 27,155 36,451 1,590 Deferred revenue, end of the period 45,263 33,614 45,263 33,614 Deferred revenue arising from business combination — 22,800 — 22,800 Revenue recognized in the period from amounts included in deferred revenue at the beginning of the period $ 12,656 $ 10,165 $ 28,280 $ 1,539

INVESTMENTS

INVESTMENTS	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS The Company's short-term and long-term investments as of September 30, 2019 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 132,217 $ 257 $ (126 ) $ 132,348 Corporate bonds 55,399 194 (92 ) 55,501 Commercial paper 2,245 — — 2,245 Municipal securities 2,713 5 (49 ) 2,669 U.S. government securities 351,592 317 (192 ) 351,717 Foreign securities 13,214 — (38 ) 13,176 Total $ 557,380 $ 773 $ (497 ) $ 557,656 Long-term debt securities: U.S. agency securities $ 87,848 $ 219 $ (164 ) $ 87,903 Corporate bonds 185,675 286 (398 ) 185,563 Municipal securities 12,668 12 (98 ) 12,582 U.S. government securities 250,434 267 (436 ) 250,265 Foreign securities 28,264 6 (75 ) 28,195 Total $ 564,889 $ 790 $ (1,171 ) $ 564,508 The Company's short-term and long-term investments as of December 31, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 80,160 $ 32 $ (70 ) $ 80,122 Corporate bonds 109,807 80 (368 ) 109,519 Municipal securities 27,839 52 (59 ) 27,832 U.S. government securities 292,615 161 (509 ) 292,267 Foreign securities 31,263 4 (16 ) 31,251 Total $ 541,684 $ 329 $ (1,022 ) $ 540,991 Long-term debt securities: U.S. agency securities $ 114,444 $ 194 $ (78 ) $ 114,560 Corporate bonds 159,783 419 (950 ) 159,252 Municipal securities 28,453 167 (26 ) 28,594 U.S. government securities 153,743 553 (172 ) 154,124 Foreign securities 8,122 28 — 8,150 Total $ 464,545 $ 1,361 $ (1,226 ) $ 464,680 For the periods presented, gains or losses realized on the sale of investments were not material. Investments are reviewed periodically to identify possible other-than-temporary impairments. As the Company has the ability and intent to hold these investments with unrealized losses for a reasonable period of time sufficient for the recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired for any of the periods presented. The amortized cost of investments classified as cash equivalents approximated the fair value due to the short-term nature of the investments. The contractual maturities of the Company's short-term and long-term investments as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 557,380 $ 557,656 Due in one to five years 564,889 564,508 Total $ 1,122,269 $ 1,122,164 The following table presents the assets underlying customer funds (in thousands): September 30, December 31, Cash $ 407,719 $ 158,697 Cash Equivalents: Money market funds 388 18 U.S. agency securities 21,667 39,991 U.S. government securities 6,999 35,349 Short-term debt securities: U.S. agency securities 1,654 27,291 U.S. government securities 222,172 72,671 Total $ 660,599 $ 334,017 The Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 1,657 $ — $ (3 ) $ 1,654 U.S. government securities 222,193 39 (60 ) 222,172 Total $ 223,850 $ 39 $ (63 ) $ 223,826 The Company's investments within customer funds as of December 31, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 27,293 $ 2 $ (4 ) $ 27,291 U.S. government securities 72,662 12 (3 ) 72,671 Total $ 99,955 $ 14 $ (7 ) $ 99,962 For the periods presented, gains or losses realized on the sale of investments were not material. Investments are reviewed periodically to identify possible other-than-temporary impairments. As the Company has the ability and intent to hold these investments with unrealized losses for a reasonable period of time sufficient for the recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired for any of the periods presented. The amortized cost of investments classified as cash equivalents approximated the fair value due to the short-term nature of the investments. The contractual maturities of the Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 223,850 $ 223,826 Total $ 223,850 $ 223,826

CUSTOMER FUNDS

CUSTOMER FUNDS	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
CUSTOMER FUNDS	INVESTMENTS The Company's short-term and long-term investments as of September 30, 2019 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 132,217 $ 257 $ (126 ) $ 132,348 Corporate bonds 55,399 194 (92 ) 55,501 Commercial paper 2,245 — — 2,245 Municipal securities 2,713 5 (49 ) 2,669 U.S. government securities 351,592 317 (192 ) 351,717 Foreign securities 13,214 — (38 ) 13,176 Total $ 557,380 $ 773 $ (497 ) $ 557,656 Long-term debt securities: U.S. agency securities $ 87,848 $ 219 $ (164 ) $ 87,903 Corporate bonds 185,675 286 (398 ) 185,563 Municipal securities 12,668 12 (98 ) 12,582 U.S. government securities 250,434 267 (436 ) 250,265 Foreign securities 28,264 6 (75 ) 28,195 Total $ 564,889 $ 790 $ (1,171 ) $ 564,508 The Company's short-term and long-term investments as of December 31, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 80,160 $ 32 $ (70 ) $ 80,122 Corporate bonds 109,807 80 (368 ) 109,519 Municipal securities 27,839 52 (59 ) 27,832 U.S. government securities 292,615 161 (509 ) 292,267 Foreign securities 31,263 4 (16 ) 31,251 Total $ 541,684 $ 329 $ (1,022 ) $ 540,991 Long-term debt securities: U.S. agency securities $ 114,444 $ 194 $ (78 ) $ 114,560 Corporate bonds 159,783 419 (950 ) 159,252 Municipal securities 28,453 167 (26 ) 28,594 U.S. government securities 153,743 553 (172 ) 154,124 Foreign securities 8,122 28 — 8,150 Total $ 464,545 $ 1,361 $ (1,226 ) $ 464,680 For the periods presented, gains or losses realized on the sale of investments were not material. Investments are reviewed periodically to identify possible other-than-temporary impairments. As the Company has the ability and intent to hold these investments with unrealized losses for a reasonable period of time sufficient for the recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired for any of the periods presented. The amortized cost of investments classified as cash equivalents approximated the fair value due to the short-term nature of the investments. The contractual maturities of the Company's short-term and long-term investments as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 557,380 $ 557,656 Due in one to five years 564,889 564,508 Total $ 1,122,269 $ 1,122,164 The following table presents the assets underlying customer funds (in thousands): September 30, December 31, Cash $ 407,719 $ 158,697 Cash Equivalents: Money market funds 388 18 U.S. agency securities 21,667 39,991 U.S. government securities 6,999 35,349 Short-term debt securities: U.S. agency securities 1,654 27,291 U.S. government securities 222,172 72,671 Total $ 660,599 $ 334,017 The Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 1,657 $ — $ (3 ) $ 1,654 U.S. government securities 222,193 39 (60 ) 222,172 Total $ 223,850 $ 39 $ (63 ) $ 223,826 The Company's investments within customer funds as of December 31, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 27,293 $ 2 $ (4 ) $ 27,291 U.S. government securities 72,662 12 (3 ) 72,671 Total $ 99,955 $ 14 $ (7 ) $ 99,962 For the periods presented, gains or losses realized on the sale of investments were not material. Investments are reviewed periodically to identify possible other-than-temporary impairments. As the Company has the ability and intent to hold these investments with unrealized losses for a reasonable period of time sufficient for the recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired for any of the periods presented. The amortized cost of investments classified as cash equivalents approximated the fair value due to the short-term nature of the investments. The contractual maturities of the Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 223,850 $ 223,826 Total $ 223,850 $ 223,826

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS The Company measures its cash equivalents, customer funds, short-term and long-term marketable debt securities, and marketable equity investments at fair value. The Company classifies these 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, 2019 December 31, 2018 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash Equivalents: Money market funds $ 304,690 $ — $ — $ 218,109 $ — $ — U.S. agency securities — 40,410 — — 46,423 — Time deposits 10,146 — — — — — U.S. government securities 23,963 — — — — — Municipal securities — — — 86,239 — — Foreign securities — — — — 23,981 — Customer funds: Money market funds 388 — — 18 — — U.S. agency securities — 23,321 — — 67,282 — U.S. government securities 229,171 — — 108,020 — — Short-term debt securities: U.S. agency securities — 132,348 — — 80,122 — Corporate bonds — 55,501 — — 109,519 — Commercial paper — 2,245 — — — — Municipal securities — 2,669 — — 27,832 — U.S. government securities 351,717 — — 292,267 — — Foreign securities — 13,176 — — 31,251 — Long-term debt securities: U.S. agency securities — 87,903 — — 114,560 — Corporate bonds — 185,563 — — 159,252 — Municipal securities — 12,582 — — 28,594 — U.S. government securities 250,265 — — 154,124 — — Foreign securities — 28,195 — — 8,150 — Other: Marketable equity investment 28,875 — — 45,342 — — Total $ 1,199,215 $ 583,913 $ — $ 904,119 $ 696,966 $ — The carrying amounts of certain financial instruments, including settlements receivable, accounts payable, customers payable, accrued expenses and settlements payable, approximate their fair values due to their short-term nature. The Company estimates the fair value of its convertible senior notes based on their last actively traded prices (Level 1) or market observable inputs (Level 2). The estimated fair value and carrying value of the convertible senior notes were as follows (in thousands): September 30, 2019 December 31, 2018 Carrying Value Fair Value (Level 2) Carrying Value Fair Value (Level 2) 2023 Notes $ 740,921 $ 961,092 $ 718,522 $ 901,468 2022 Notes 187,948 575,661 181,173 515,693 Total $ 928,869 $ 1,536,753 $ 899,695 $ 1,417,161 The estimated fair value and carrying value of loans held for sale is as follows (in thousands): September 30, 2019 December 31, 2018 Carrying Value Fair Value (Level 3) Carrying Value Fair Value (Level 3) Loans held for sale $ 120,776 $ 126,218 $ 89,974 $ 93,064 Total $ 120,776 $ 126,218 $ 89,974 $ 93,064 For the three and nine months ended September 30, 2019 , the Company recorded a charge for the excess of amortized cost over fair value of the loans of $5.3 million and $18.4 million , respectively. For the three and nine months ended September 30, 2018 , the Company recorded a charge for the excess of amortized cost over fair value of the loans of $3.3 million and $9.0 million , respectively. 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, 2019 and 2018 , the Company did not have any transfers in or out of Level 1, Level 2, or Level 3 assets or liabilities.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET The following is a summary of property and equipment, less accumulated depreciation and amortization (in thousands): September 30, December 31, Leasehold improvements $ 108,980 $ 107,611 Computer equipment 91,464 80,093 Capitalized software 76,656 58,908 Office furniture and equipment 23,284 20,699 300,384 267,311 Less: Accumulated depreciation and amortization (166,350 ) (124,909 ) Property and equipment, net $ 134,034 $ 142,402 Depreciation and amortization expense on property and equipment was $15.3 million and $45.6 million for the three and nine months ended September 30, 2019 , respectively. Depreciation and amortization expense on property and equipment was $11.7 million and $29.2 million for the three and nine months ended September 30, 2018 , respectively.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Weebly, Inc. On May 31, 2018 , the Company acquired 100% of the outstanding shares of Weebly, Inc., a technology company that offers customers website hosting and domain name registration solutions. The acquisition of Weebly enabled the Company to combine Weebly’s web presence tools with the Company's in-person and online offerings to create a cohesive solution for sellers to start or grow an omnichannel business. The acquisition expanded the Company’s customer base globally and added a new recurring revenue stream. The purchase consideration was comprised of $132.4 million in cash and 2,418,271 shares of the Company’s Class A common stock with an aggregate fair value of $140.1 million based on the closing price of the Company’s Class A common stock on the acquisition date. As part of the acquisition, the Company paid an aggregate of $17.7 million in cash and shares to settle outstanding vested and unvested employee options, of which $2.6 million was accounted for as post-combination compensation expense and is excluded from the purchase consideration. Third-party acquisition-related costs were insignificant. The results of Weebly's operations have been included in the consolidated financial statements since the closing date. The acquisition was accounted for as a business combination. This method requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date and that the difference between the fair value of the consideration paid for the acquired entity and the fair value of the net assets acquired be recorded as goodwill, which is not amortized but is tested at least annually for impairment. The table below summarizes the consideration paid for Weebly and the preliminary assessment of the fair value of the assets acquired and liabilities assumed at the closing date (in thousands, except share data). Consideration: Cash $ 132,432 Stock (2,418,271 shares of Class A common stock) 140,107 $ 272,539 Recognized amounts of identifiable assets acquired and liabilities assumed: Current assets (inclusive of cash acquired of $25,758) $ 46,978 Intangible customer assets 42,700 Intangible technology assets 14,900 Intangible trade name 11,300 Intangible other assets 961 Total liabilities assumed (including deferred revenue of $22,800) (37,509 ) Total identifiable net assets acquired 79,330 Goodwill 193,209 Total $ 272,539 The Company had prepared an initial determination of the fair value of the assets acquired and liabilities assumed as of the acquisition date using preliminary information. Subsequently, the Company recognized measurement period adjustments to the purchase consideration and the fair value of certain liabilities assumed as a result of further refinements in the Company’s estimates. These adjustments were prospectively applied. The effect of these adjustments on the preliminary purchase price allocation was an increase in goodwill and tax liabilities assumed of $3.7 million and $4.7 million , respectively. There was no impact to the consolidated statements of operations as result of these adjustments. As of September 30, 2019 , $19.4 million of cash and 363,266 shares of the total consideration were withheld as security for indemnification obligations related to general representations and warranties, in addition to certain potential tax exposures. Goodwill from the Weebly acquisition is primarily attributable to the value of expected synergies created by incorporating Weebly solutions into the Company's technology platform and the value of the assembled workforce. None of the goodwill generated from the Weebly acquisition or the acquired intangible assets are expected to be deductible for tax purposes. Additionally, the acquisition would have resulted in recognition of deferred tax assets arising mainly from the net of deferred tax assets from acquired net operating losses (NOLs) and research and development credits, and deferred tax liabilities associated with intangible assets and deferred revenue. However, the realization of such deferred tax assets depends primarily on the Company's post-acquisition ability to generate taxable income in future periods. Accordingly, a valuation allowance was recorded against the net acquired deferred tax asset in accounting for the acquisition. The acquisition of Weebly did not have a material impact on the Company's reported revenue or net loss amounts for any period presented. Accordingly, pro forma financial information has not been presented. Other acquisitions The Company spent an aggregate of $20.4 million , net of cash acquired, in connection with other immaterial acquisitions during the nine months ended September 30, 2019, which resulted in the recognition of additional intangible assets and goodwill. Pro forma financial information has not been presented for any of our acquisitions as the impact to our consolidated financial statements was not material.

ASSETS AND LIABILITIES HELD FOR

ASSETS AND LIABILITIES HELD FOR SALE	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
ASSETS AND LIABILITIES HELD FOR SALE	ASSETS AND LIABILITIES HELD FOR SALE On July 31, 2019 , the Company entered into a definitive agreement with DoorDash, Inc. for the sale of the Company’s Caviar business, which offers food ordering and delivery services to customers. The transaction closed on October 31, 2019 and the Company received $410 million in gross proceeds comprised of $310 million in cash and $100 million of DoorDash, Inc.'s preferred stock.The Company agreed to indemnify DoorDash for potential losses and costs that may arise from certain legal and other matters. The Caviar business is a small component of the Company's overall business comprising less than 5% of the Company's consolidated total assets and revenues. The sale is in line with the Company's strategy of focusing investment on its larger and growing managed payments and Cash App businesses. Accordingly the sale of the Caviar business does not represent a strategic shift that will have a major effect on the Company's operations and financial results, and does not therefore qualify for reporting as a discontinued operation. The carrying values of the assets and liabilities to be held for sale were reported within other current assets and other current liabilities on the consolidated balance sheets. The following table summarizes the carrying values of the assets and liabilities classified as held for sale as of September 30, 2019 (in thousands): Balance at September 30, 2019 Assets held for sale Intangible assets $ 7,582 Goodwill 4,186 Property and equipment, net 1,098 Operating lease right-of-use assets 791 Total assets held for sale, included within other assets 13,657 Liabilities held for sale Operating lease liabilities, current 754 Net assets held for sale $ 12,903

GOODWILL

GOODWILL	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL Goodwill is recorded when the consideration paid for an acquisition of a business exceeds the fair value of identifiable net tangible and intangible assets acquired. The change in carrying value of goodwill in the period was as follows (in thousands): Balance at December 31, 2018 $ 261,705 Acquisitions 10,832 Transfer to assets held for sale (Note 8) (4,186 ) Other adjustments (2,377 ) Balance at September 30, 2019 $ 265,974 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, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
ACQUIRED INTANGIBLE ASSETS	ACQUIRED INTANGIBLE ASSETS During the three and nine months ended September 30, 2019 , the Company did not make any material acquisitions. The following table presents the detail of acquired intangible assets as of the periods presented (in thousands): Balance at September 30, 2019 Cost Accumulated Amortization Net Technology assets 54,630 (30,682 ) 23,948 Customer assets 44,045 (6,089 ) 37,956 Trade name 11,300 (3,767 ) 7,533 Other 5,299 (1,943 ) 3,356 Total $ 115,274 $ (42,481 ) $ 72,793 Balance at December 31, 2018 Cost Accumulated Amortization Net Technology assets $ 45,978 $ (28,420 ) $ 17,558 Customer assets 57,109 (8,068 ) 49,041 Trade name 11,300 (1,648 ) 9,652 Other 2,246 (1,395 ) 851 Total $ 116,633 $ (39,531 ) $ 77,102 All intangible assets are amortized over their estimated useful lives. The weighted average amortization periods for acquired technology, customer intangible assets, and acquired trade name are approximately 5 years , 12 years and 4 years , respectively. The changes to the carrying value of intangible assets were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Acquired intangible assets, net, beginning of the period $ 84,216 $ 85,514 $ 77,102 $ 14,334 Acquisitions — — 14,559 75,871 Amortization expense (3,841 ) (4,384 ) (11,286 ) (9,075 ) Transfer to assets held for sale (Note 8) (7,582 ) — (7,582 ) — Acquired intangible assets, net, end of the period $ 72,793 $ 81,130 $ 72,793 $ 81,130 The total estimated future amortization expense of these intangible assets as of September 30, 2019 is as follows (in thousands): 2019 (remaining 3 months) $ 3,714 2020 12,800 2021 11,829 2022 10,134 2023 8,917 Thereafter 25,399 Total $ 72,793

OTHER CONSOLIDATED BALANCE SHEE

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT)	9 Months Ended
	Sep. 30, 2019
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, Inventory, net $ 44,690 $ 28,627 Processing costs receivable 63,652 46,102 Prepaid expenses 17,341 21,782 Accounts receivable, net 37,564 22,393 Assets held for sale (Note 8) 13,657 — Other 38,902 46,062 Total $ 215,806 $ 164,966 Accrued Expenses The following table presents the detail of accrued expenses (in thousands): September 30, December 31, Accrued facilities expenses $ 21,302 $ 13,040 Accrued payroll 21,313 9,612 Accrued advertising and other marketing 20,070 12,201 Processing costs payable 13,199 12,683 Accrued non income tax liabilities 8,383 9,503 Other accrued liabilities 39,738 25,315 Total $ 124,005 $ 82,354 Other Current Liabilities The following table presents the detail of other current liabilities (in thousands): September 30, December 31, Accounts payable $ 37,156 $ 36,416 Deferred revenue, current 39,025 31,474 Square Capital payable (i) 5,851 6,092 Square Payroll payable (ii) 13,304 7,534 Other 12,731 17,637 Total $ 108,067 $ 99,153 (i) Square Capital payable represents unpaid amounts arising from the purchase of loans or loan repayments collected on behalf of third parties. (ii) Square Payroll payable represents amounts received from Square Payroll product customers that will be utilized to settle the customers' employee payroll and related obligations. Other Non-Current Assets The following table presents the detail of other non-current assets (in thousands): September 30, December 31, Marketable equity investment (i) $ 28,875 $ 45,342 Non-current lease prepayments 34,199 — Other 18,252 13,051 Total $ 81,326 $ 58,393 (i) This balance represents the Company's investment in Class B common shares of Eventbrite, Inc. (Eventbrite). The investment is carried at fair value with changes in fair value being recorded on the consolidated statement of operations. During the three and nine months ended September 30, 2019 , the Company recorded a gain of $ 2.5 million and a loss of $16.5 million , respectively, to other expense (income), net on the consolidated statements of operations arising from revaluation of this investment. Other Non-Current Liabilities The following table presents the detail of other non-current liabilities (in thousands): September 30, December 31, Statutory liabilities (i) $ 51,623 $ 54,748 Deferred rent, non-current (ii) — 23,003 Deferred revenue, non-current 6,238 4,977 Other 12,622 10,558 Total $ 70,483 $ 93,286 (i) Statutory liabilities represent loss contingencies that may arise from the Company's interpretation and application of certain guidelines and rules issued by various federal, state, local, and foreign regulatory authorities. (ii) The adoption of ASC 842 on January 1, 2019 resulted in the reclassification of deferred rent as an offset to right-of-use lease assets.

OTHER CONSOLIDATED BALANCE SH_2

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT)	9 Months Ended
	Sep. 30, 2019
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, Inventory, net $ 44,690 $ 28,627 Processing costs receivable 63,652 46,102 Prepaid expenses 17,341 21,782 Accounts receivable, net 37,564 22,393 Assets held for sale (Note 8) 13,657 — Other 38,902 46,062 Total $ 215,806 $ 164,966 Accrued Expenses The following table presents the detail of accrued expenses (in thousands): September 30, December 31, Accrued facilities expenses $ 21,302 $ 13,040 Accrued payroll 21,313 9,612 Accrued advertising and other marketing 20,070 12,201 Processing costs payable 13,199 12,683 Accrued non income tax liabilities 8,383 9,503 Other accrued liabilities 39,738 25,315 Total $ 124,005 $ 82,354 Other Current Liabilities The following table presents the detail of other current liabilities (in thousands): September 30, December 31, Accounts payable $ 37,156 $ 36,416 Deferred revenue, current 39,025 31,474 Square Capital payable (i) 5,851 6,092 Square Payroll payable (ii) 13,304 7,534 Other 12,731 17,637 Total $ 108,067 $ 99,153 (i) Square Capital payable represents unpaid amounts arising from the purchase of loans or loan repayments collected on behalf of third parties. (ii) Square Payroll payable represents amounts received from Square Payroll product customers that will be utilized to settle the customers' employee payroll and related obligations. Other Non-Current Assets The following table presents the detail of other non-current assets (in thousands): September 30, December 31, Marketable equity investment (i) $ 28,875 $ 45,342 Non-current lease prepayments 34,199 — Other 18,252 13,051 Total $ 81,326 $ 58,393 (i) This balance represents the Company's investment in Class B common shares of Eventbrite, Inc. (Eventbrite). The investment is carried at fair value with changes in fair value being recorded on the consolidated statement of operations. During the three and nine months ended September 30, 2019 , the Company recorded a gain of $ 2.5 million and a loss of $16.5 million , respectively, to other expense (income), net on the consolidated statements of operations arising from revaluation of this investment. Other Non-Current Liabilities The following table presents the detail of other non-current liabilities (in thousands): September 30, December 31, Statutory liabilities (i) $ 51,623 $ 54,748 Deferred rent, non-current (ii) — 23,003 Deferred revenue, non-current 6,238 4,977 Other 12,622 10,558 Total $ 70,483 $ 93,286 (i) Statutory liabilities represent loss contingencies that may arise from the Company's interpretation and application of certain guidelines and rules issued by various federal, state, local, and foreign regulatory authorities. (ii) The adoption of ASC 842 on January 1, 2019 resulted in the reclassification of deferred rent as an offset to right-of-use lease assets.

INDEBTEDNESS

INDEBTEDNESS	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
INDEBTEDNESS	INDEBTEDNESS Revolving Credit Facility In November 2015 , the Company entered into a revolving credit agreement with certain lenders, which extinguished the prior revolving credit agreement and provided for a $375.0 million revolving secured credit facility maturing in November 2020 . This revolving credit agreement is secured by certain tangible and intangible assets. Loans under the credit facility bear interest at the Company’s option of (i) a base rate based on the highest of the prime rate, the federal funds rate plus 0.50% , and an adjusted LIBOR rate for a one-month interest period, in each case plus a margin ranging from 0.00% to 1.00% , or (ii) an adjusted LIBOR rate plus a margin ranging from 1.00% to 2.00% . This margin is determined based on the Company’s total leverage ratio for the preceding four fiscal quarters. The Company is obligated to pay other customary fees for a credit facility of this size and type including an annual administrative agent fee of $0.1 million and an unused commitment fee of 0.15% . To date no funds have been drawn under the credit facility, with $375.0 million remaining available. The Company paid $0.1 million and $0.4 million in unused commitment fees during both the three and nine months ended September 30, 2019 and 2018 , respectively. As of September 30, 2019 , the Company was in compliance with all financial covenants associated with this credit facility. Convertible Senior Notes due in 2023 On May 25, 2018, the Company issued an aggregate principal amount of $862.5 million of convertible senior notes (2023 Notes). The 2023 Notes mature on May 15, 2023, unless earlier converted or repurchased, and bear interest at a rate of 0.50% payable semi-annually on May 15 and November 15 of each year. The 2023 Notes are convertible at an initial conversion rate of 12.8456 shares of the Company's Class A common stock per $1,000 principal amount of 2023 Notes, which is equivalent to an initial conversion price of approximately $77.85 per share of Class A common stock. Holders may convert their 2023 Notes at any time prior to the close of business on the business day immediately preceding February 15, 2023 only under the following circumstances: (1) during any calendar quarter commencing after September 30, 2018 (and only during such calendar quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the measurement period) in which the trading price (as defined in the indenture governing the 2023 Notes) per $1,000 principal amount of 2023 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events, including certain distributions, the occurrence of a fundamental change (as defined in the indenture governing the 2023 Notes) or a transaction resulting in the Company’s Class A common stock converting into other securities or property or assets. On or after February 15, 2023, up until the close of business on the second scheduled trading day immediately preceding the maturity date, a holder may convert all or any portion of its 2023 Notes regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its Class A common stock, or a combination of cash and shares of its Class A common stock, at the Company’s election. The Company's current policy is to settle conversions entirely in shares of the Company's Class A common stock. The Company will reevaluate this policy from time to time as conversion notices are received from holders of the 2023 Notes. The circumstances required to allow the holders to convert their 2023 Notes were not met during the nine months ended September 30, 2019. In accounting for the issuance of the 2023 Notes, the Company separated the 2023 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $155.3 million and was determined by deducting the fair value of the liability component from the par value of the 2023 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount ("debt discount") is amortized to interest expense over the term of the 2023 Notes at an effective interest rate of 4.69% over the contractual terms of the 2023 Notes. Debt issuance costs related to the 2023 Notes comprised of discounts and commissions payable to the initial purchasers of $6.0 million and third party offering costs of $0.8 million . The Company allocated the total amount incurred to the liability and equity components of the 2023 Notes based on their relative values. Issuance costs attributable to the liability component were $5.6 million and will be amortized to interest expense using the effective interest method over the contractual term. Issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity. Convertible Senior Notes due in 2022 On March 6, 2017, the Company issued an aggregate principal amount of $440.0 million of convertible senior notes (2022 Notes). The 2022 Notes mature on March 1, 2022, unless earlier converted or repurchased, and bear interest at a rate of 0.375% payable semi-annually on March 1 and September 1 of each year. The 2022 Notes are convertible at an initial conversion rate of 43.5749 shares of the Company's Class A common stock per $1,000 principal amount of 2022 Notes, which is equivalent to an initial conversion price of approximately $22.95 per share of Class A common stock. Holders may convert their 2022 Notes at any time prior to the close of business on the business day immediately preceding December 1, 2021 only under the following circumstances: (1) during any calendar quarter (and only during such calendar quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the measurement period) in which the trading price (as defined in the indenture governing the 2022 Notes) per $1,000 principal amount of 2022 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events, including certain distributions, the occurrence of a fundamental change (as defined in the indenture governing the 2022 Notes) or a transaction resulting in the Company’s Class A common stock converting into other securities or property or assets. On or after December 1, 2021, up until the close of business on the second scheduled trading day immediately preceding the maturity date, a holder may convert all or any portion of its 2022 Notes regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its Class A common stock, or a combination of cash and shares of its Class A common stock, at the Company’s election. The circumstances required to allow the holders to convert their 2022 Notes were met starting January 1, 2018 and continued to be met through September 30, 2019 . In 2018, certain holders of the 2022 Notes converted an aggregate principal amount of $228.3 million of their Notes. The Company settled the conversions through a combination of $219.4 million in cash and issuance of 7.3 million shares of the Company's Class A common stock. Conversions in the nine months ended September 30, 2019 were not material. The Company currently expects to settle future conversions entirely in shares of the Company's Class A common stock. The Company will reevaluate this policy from time to time as conversion notices are received from holders of the 2022 Notes. In accounting for the issuance of the 2022 Notes, the Company separated the 2022 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $86.2 million and was determined by deducting the fair value of the liability component from the par value of the 2022 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The debt discount is amortized to interest expense over the term of the 2022 Notes at an effective interest rate of 5.34% over the contractual terms of the 2022 Notes. Debt issuance costs related to the 2022 Notes comprised of discounts and commissions payable to the initial purchasers of $11.0 million and third party offering costs of $0.8 million . The Company allocated the total amount incurred to the liability and equity components of the 2022 Notes based on their relative values. Issuance costs attributable to the liability component were $9.4 million and will be amortized to interest expense using the effective interest method over the contractual term. Issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity. The debt component associated with the 2022 Notes that were converted as of December 31, 2018, was accounted for as an extinguishment of debt, with the Company recording loss on extinguishment of $5.0 million , as the difference between the estimated fair value and the carrying value of such 2022 Notes. The equity component associated with the 2022 Notes that were converted was accounted for as a reacquisition of equity upon the conversion of such 2022 Notes. Accordingly, the excess of the fair value of the consideration issued to settle the conversion over the fair value of the debt component of $21.0 million was accounted for as a reduction to the additional paid in capital. The net carrying amount of the Notes were as follows (in thousands): Principal outstanding Unamortized debt discount Unamortized debt issuance costs Net carrying value September 30, 2019 2023 Notes $ 862,500 $ (117,932 ) $ (3,647 ) $ 740,921 2022 Notes 211,726 (21,400 ) (2,378 ) 187,948 Total $ 1,074,226 $ (139,332 ) $ (6,025 ) $ 928,869 December 31, 2018 2023 Notes $ 862,500 $ (138,924 ) $ (5,054 ) $ 718,522 2022 Notes 211,728 (27,569 ) (2,986 ) 181,173 $ 1,074,228 $ (166,493 ) $ (8,040 ) $ 899,695 The net carrying amount of the equity component of the 2023 Notes and 2022 Notes were as follows (in thousands): Amount allocated to conversion option Less: allocated issuance costs Equity component, net September 30, 2019 and December 31, 2018 2023 Notes $ 155,250 $ (1,231 ) $ 154,019 2022 Notes 41,481 (1,108 ) 40,373 Total $ 196,731 $ (2,339 ) $ 194,392 The Company recognized interest expense on the Notes as follows (in thousands, except for percentages): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Contractual interest expense $ 1,277 $ 1,469 $ 3,831 $ 2,732 Amortization of debt discount and issuance costs 9,843 11,627 29,176 22,850 Total $ 11,120 $ 13,096 $ 33,007 $ 25,582 The effective interest rate of the liability component is 4.69% and 5.34% for the 2023 Notes and 2022 Notes, respectively. Convertible Note Hedge and Warrant Transactions In connection with the offering of the 2023 Notes, the Company entered into convertible note hedge transactions (2023 convertible note hedges) with certain financial institution counterparties (2018 Counterparties) whereby the Company has the option to purchase a total of approximately 11.1 million shares of its Class A common stock at a price of approximately $77.85 per share. The total cost of the 2023 convertible note hedge transactions was $172.6 million . In addition, the Company sold warrants (2023 warrants) to the 2018 Counterparties whereby the 2018 Counterparties have the option to purchase a total of 11.1 million shares of the Company’s Class A common stock at a price of approximately $109.26 per share. The Company received $112.1 million in cash proceeds from the sale of the 2023 warrants. Taken together, the purchase of the 2023 convertible note hedges and sale of the 2023 warrants are intended to reduce dilution from the conversion of the 2023 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of the converted 2023 Notes, as the case may be, and to effectively increase the overall conversion price from approximately $77.85 per share to approximately $109.26 per share. As these instruments are considered indexed to the Company's own stock and are considered equity classified, the 2023 convertible note hedges and 2023 warrants are recorded in stockholders’ equity, are not accounted for as derivatives and are not remeasured each reporting period. The net costs incurred in connection with the 2023 convertible note hedge and 2023 warrant transactions were recorded as a reduction to additional paid-in capital on the condensed consolidated balance sheets. In connection with the offering of the 2022 Notes, the Company entered into convertible note hedge transactions (2022 convertible note hedges) with certain financial institution counterparties (2017 Counterparties) whereby the Company has the option to purchase a total of approximately 19.2 million shares of its Class A common stock at a price of approximately $22.95 per share. The total cost of the 2022 convertible note hedge transactions was $92.1 million . In addition, the Company sold warrants (2022 warrants) to the 2017 Counterparties whereby the 2017 Counterparties have the option to purchase a total of 19.2 million shares of the Company’s Class A common stock at a price of approximately $31.18 per share. The Company received $57.2 million in cash proceeds from the sale of the 2022 warrants. Taken together, the purchase of the 2022 convertible note hedges and sale of the 2022 warrants are intended to reduce dilution from the conversion of the 2022 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of the converted 2022 Notes, as the case may be, and to effectively increase the overall conversion price from approximately $22.95 per share to approximately $31.18 per share. As these instruments are considered indexed to the Company's own stock and are considered equity classified, the 2022 convertible note hedges and 2022 warrants are recorded in stockholders’ equity, are not accounted for as derivatives and are not remeasured each reporting period. The net costs incurred in connection with the 2022 convertible note hedge and 2022 warrant transactions were recorded as a reduction to additional paid-in capital on the condensed consolidated balance sheets. In 2018, the Company exercised a pro-rata portion of the 2022 convertible note hedges to offset the shares of the Company's Class A common stock issued to settle the conversion of the 2022 Notes discussed above. The 2022 convertible note hedges were net share settled, and the Company received 6.9 million shares of the Company's Class A common stock from the 2017 Counterparties in 2018. During the nine months ended September 30, 2019, the Company received an additional 0.3 million shares of the Company's Class A common stock.

ACCRUED TRANSACTION LOSSES

ACCRUED TRANSACTION LOSSES	9 Months Ended
	Sep. 30, 2019
Product Warranties Disclosures [Abstract]
ACCRUED TRANSACTION LOSSES	ACCRUED TRANSACTION LOSSES The Company is exposed to transaction losses due to chargebacks as a result of fraud or uncollectibility. The following table summarizes the activities of the Company’s reserve for transaction losses (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Accrued transaction losses, beginning of the period $ 39,630 $ 29,207 $ 33,682 $ 26,893 Provision for transaction losses 18,225 20,449 60,223 48,794 Charge-offs to accrued transaction losses (20,436 ) (14,324 ) (56,486 ) (40,355 ) Accrued transaction losses, end of the period $ 37,419 $ 35,332 $ 37,419 $ 35,332

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company recorded an income tax expense of $2.6 million and $2.3 million for the three and nine months ended September 30, 2019 , respectively, compared to income tax expense of $1.1 million and $1.8 million for the three and nine months ended September 30, 2018 , respectively. The income tax expense recorded for the three and nine months ended September 30, 2019 was primarily due to state and foreign income tax expense offset by a change in the valuation allowance on the Company's deferred tax assets. The Company’s effective tax rate was 8.1% and (17.1)% for the three and nine months ended September 30, 2019 , respectively, compared to an effective tax rate of 5.1% and (22.0)% for the three and nine months ended September 30, 2018 , respectively. The difference between the effective tax rate and the federal statutory tax rate for the three and nine months ended September 30, 2019 and September 30, 2018 primarily relates to tax losses in the U.S. and certain foreign jurisdictions for which no benefit can be taken. 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, 2019 , 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, 2019 and September 30, 2018 , was calculated on a jurisdictional 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, 2019
Share-based Payment Arrangement [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Common Stock The Company has authorized the issuance of Class A common stock and Class B common stock. Holders of shares of Class A common stock are entitled to one vote per share, while holders of shares of Class B common stock are entitled to ten votes per share. Shares of the Company's Class B common stock are convertible into an equivalent number of shares of its Class A common stock and generally convert into shares of its Class A common stock upon transfer. The holders of Class A common stock and Class B common stock have no preemptive or other subscription rights and there are no redemption or sinking fund provisions with respect to such shares. 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, 2019 , 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, 2019 , there were 346,552,092 shares of Class A common stock and 82,521,716 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. Warrants In conjunction with the 2023 Notes offering, the Company sold the 2023 warrants whereby the 2018 Counterparties have the option to purchase a total of approximately 11.1 million shares of the Company’s Class A common stock at a price of $109.26 per share. The Company received $112.1 million in cash proceeds from the sale of the 2023 warrants. See Note 13 , Indebtedness , for more details on this transaction. In conjunction with the 2022 Notes offering, the Company sold warrants whereby the 2017 Counterparties have the option to purchase a total of approximately 19.2 million shares of the Company’s Class A common stock at a price of $31.18 per share. None of the warrants associated with the 2022 and 2023 Notes offering were exercised as of September 30, 2019. Stock Plans The Company maintains two share-based employee compensation plans: the 2009 Stock Plan (2009 Plan) and the 2015 Equity Incentive Plan (2015 Plan). The 2015 Plan serves as the successor to the 2009 Plan. The 2015 Plan became effective as of November 17, 2015. Outstanding awards under the 2009 Plan continue to be subject to the terms and conditions of the 2009 Plan. Since November 17, 2015, no additional awards have been nor will be in the future granted under the 2009 Plan. Under the 2015 Plan, shares of the Company's Class A common stock are reserved for the issuance of incentive and nonstatutory stock options, restricted stock awards (RSAs), restricted stock units (RSUs), performance shares, and stock bonuses to qualified employees, directors, and consultants. The awards must be granted at a price per share not less than the fair market value at the date of grant. Initially, 30,000,000 shares were reserved under the 2015 Plan, and any shares subject to options or other similar awards granted under the 2009 Plan that expire, are forfeited, are repurchased by the Company, or otherwise terminate unexercised, will become available under the 2015 Plan. The number of shares available for issuance under the 2015 Plan will be increased on the first day of each fiscal year, in an amount equal to the least of (i) 40,000,000 shares, (ii) 5% of the outstanding shares on the last day of the immediately preceding fiscal year, or (iii) such number of shares determined by the Company’s board of directors or a committee thereof. As of September 30, 2019 , the total number of shares subject to stock options, RSAs and RSUs outstanding under the 2015 Plan was 21,822,262 , and 82,968,841 shares were available for future issuance. As of September 30, 2019 , the total number of shares subject to stock options, RSAs and RSUs outstanding under the 2009 Plan was 20,422,313 . A summary of stock option activity for the nine months ended September 30, 2019 is as follows (in thousands, except share and per share data): Number of Stock Options Outstanding Weighted Weighted Aggregate Balance at December 31, 2018 33,152,881 $ 9.52 5.45 $ 1,543,793 Granted 1,184,657 72.15 Exercised (7,881,289 ) 7.97 Forfeited (136,772 ) 11.70 Balance at September 30, 2019 26,319,477 $ 12.80 5.23 $ 1,305,789 Options exercisable as of September 30, 2019 24,136,540 $ 9.40 4.92 $ 1,269,509 Restricted Stock Activity Activity related to RSAs and RSUs during the nine months ended September 30, 2019 is set forth below: Number of Weighted Unvested as of December 31, 2018 17,934,728 $ 31.34 Granted 5,735,224 73.29 Vested (6,016,950 ) 29.05 Forfeited (1,727,904 ) 35.90 Unvested as of September 30, 2019 15,925,098 $ 46.82 Share-Based Compensation The fair value of stock options and employee stock purchase plan rights are estimated on the date of grant using the Black-Scholes-Merton option valuation model. The fair value of RSAs and RSUs is determined by the closing price of the Company’s common stock on each grant date. The fair value of stock options granted was estimated using the following weighted-average assumptions: Nine Months Ended September 30, 2019 2018 Dividend yield — % — % Risk-free interest rate 2.48 % 2.92 % Expected volatility 39.52 % 30.87 % Expected term (years) 6.05 6.19 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, 2019 2018 2019 2018 Cost of revenue $ 38 $ 18 $ 88 $ 79 Product development 56,321 39,525 155,114 103,813 Sales and marketing 6,269 6,108 20,304 16,703 General and administrative 14,798 13,262 42,474 37,261 Total $ 77,426 $ 58,913 $ 217,980 $ 157,856 The Company recorded $5.1 million and $14.1 million of share-based compensation expense related to the Company's 2015 Employee Stock Purchase Plan during the three and nine months ended September 30, 2019 , respectively, compared to $2.0 million and $6.3 million for the three and nine months ended September 30, 2018 , which are included in the table above. The Company capitalized $2.4 million and $6.0 million of share-based compensation expense related to capitalized software costs during the three and nine months ended September 30, 2019 , respectively, compared to $2.0 million and $6.3 million for the three and nine months ended September 30, 2018 , respectively. As of September 30, 2019 , there was $745.0 million of total unrecognized compensation cost related to outstanding awards that are expected to be recognized over a weighted-average period of 2.8 years .

NET INCOME (LOSS) PER SHARE

NET INCOME (LOSS) PER SHARE	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER SHARE	NET INCOME (LOSS) PER SHARE Basic net income (loss) per share is computed by dividing the net income (loss) by the weighted-average number of shares of common stock outstanding during the period. Diluted net income per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding adjusted for the dilutive effect of all potential shares of common stock. In periods when the Company reported a net loss, diluted net loss per share is the same as basic net loss per share because the effects of potentially dilutive items were anti-dilutive. The following table presents the calculation of basic and diluted net income (loss) per share (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: Net income (loss) $ 29,397 $ 19,643 $ (15,494 ) $ (10,249 ) Denominator: Basic shares: Weighted-average common shares outstanding 427,906 410,095 423,957 403,577 Weighted-average unvested shares (782 ) (405 ) (718 ) (597 ) Weighted-average shares used to compute basic net loss per share 427,124 409,690 423,239 402,980 Diluted shares: Stock options and restricted stock units 28,549 47,175 — — Convertible senior notes — 6,409 — — Common stock warrants 10,372 11,422 — — Employee stock purchase plan 54 219 — — Weighted-average shares used to compute diluted net income (loss) per share 466,099 474,915 423,239 402,980 Net income (loss) per share: Basic $ 0.07 $ 0.05 $ (0.04 ) $ (0.03 ) Diluted $ 0.06 $ 0.04 $ (0.04 ) $ (0.03 ) Additionally, since the Company intends to settle future conversions of its outstanding 2022 Notes and 2023 Notes entirely in shares of its Class A common stock, the Company will consider the number of shares expected to be issued in calculating any potential dilutive effect of the conversions, if applicable. The following potential common shares were excluded from the calculation of diluted net income (loss) per share because their effect would have been anti-dilutive for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Stock options and restricted stock units 15,113 12,079 46,045 62,822 Common stock warrants 19,880 18,830 30,252 24,387 Convertible senior notes 20,305 23,415 20,305 24,276 Unvested shares 782 405 718 597 Employee stock purchase plan 189 26 217 207 Total anti-dilutive securities 56,269 54,755 97,537 112,289

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS In July 2019, the Company entered into a lease agreement to lease certain office space located in St. Louis, Missouri, from an affiliate of one of the Company’s co-founders and current member of its board and directors, Mr. Jim McKelvey, under an operating lease agreement as discussed in Note 19 , Commitments and Contingencies. The lease commencement date is expected to be in April 2020. The term of the agreement is 15.5 years with total future minimum lease payments over the term of approximately $42.7 million . The Company has not yet recognized a right of use asset and lease obligation under this agreement as of September 30, 2019.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Operating and Finance Leases The Company’s operating leases are primarily comprised of office facilities, with the most significant leases relating to corporate headquarters in San Francisco and an office in New York. The Company's leases have remaining lease terms of 1 year to 12 years , some of which include options to extend for 5 year terms, or include options to terminate the leases within 1 year . None of the options to extend the leases have been included in the measurement of the right of use asset or the associated lease liability. The Company elects to apply the short-term lease measurement and recognition exemption to its leases where applicable. Operating lease right-of-use assets and operating lease liabilities are recognized at the present value of the future lease payments at the lease commencement date for each lease. The interest rate used to determine the present value of the future lease payments is our incremental borrowing rate because the interest rate implicit in most of the Company's leases is not readily determinable. The Company's incremental borrowing rate is estimated to approximate the interest rate that the Company would pay to borrow on a collateralized basis with similar terms and payments as the lease, and in economic environments where the leased asset is located. Operating lease right-of-use assets also include any prepaid lease payments and lease incentives. Operating lease expense is recognized on a straight-line basis over the lease term. The Company's lease agreements generally contain lease and non-lease components. Non-lease components, which primarily include payments for maintenance and utilities, are combined with lease payments and accounted for as a single lease component. The Company includes the fixed non-lease components in the determination of the right-of-use assets and operating lease liabilities. In December 2018, the Company entered into a lease arrangement for 355,762 square feet of office space in Oakland, California for a term of 12 years with options to extend the lease term for two 5 year terms. The lease commencement date is expected to be in January 2020 with total lease payments over the term of approximately $276 million . Under the terms of this lease, the Company is required to make certain payments during the construction stage of the office space, which the Company will record as a prepaid lease asset. In July 2019, the Company entered into a lease arrangement for 226,258 square feet of office space in St Louis, Missouri, with an affiliate of one of the Company’s co-founders, Mr. Jim McKelvey, who is also a Company stockholder and a member of its board of directors, for a term of 15.5 years with options to extend the lease term for two 5 year terms. The Company also has an option to terminate the lease for up to 50% of the leased space any time between January 1, 2024 and December 31, 2026, as well as an option to terminate the lease for the entire property on January 1, 2034. Termination penalties specified in the lease agreement will apply if the Company exercises any of the options to terminate the lease. The lease commencement date is expected to be in April 2020 with total future minimum lease payments over the term of approximately $42.7 million . Additionally, the Company has finance leases for data center equipment, with remaining lease terms of approximately 2 years . The components of lease expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 Fixed operating lease costs $ 7,449 $ 21,626 Variable operating lease costs 1,646 3,871 Sublease income (1,468 ) (1,570 ) Finance lease costs Amortization of finance right-of-use assets 1,284 3,861 Interest on finance lease liabilities — — Total lease costs $ 8,911 $ 27,788 For the periods presented, costs associated with short-term leases were not material. Other information related to leases was as follows: September 30, 2019 Weighted Average Remaining Lease Term: Operating leases 4.5 years Finance leases 0.9 years Weighted Average Discount Rate: Operating leases 4 % Finance leases — % Cash flows related to leases were as follows (in thousands): Nine Months Ended September 30, 2019 Cash flows from operating activities: Payments for operating lease liabilities $ 24,580 Cash flows from financing activities: Principal payments on finance lease obligation $ 3,860 Supplemental Cash Flow Data: Right-of-use assets obtained in exchange for operating lease obligations $ 31,013 Future minimum lease payments under non-cancelable operating leases (with initial lease terms in excess of one year) and future minimum finance lease payments as of September 30, 2019 are as follows (in thousands): Finance Operating Year: 2019 (remaining 3 months) $ 1,178 $ 5,942 2020 2,446 40,388 2021 — 59,459 2022 — 61,005 2023 — 54,842 Thereafter — 270,872 Total $ 3,624 $ 492,508 Less: amount representing interest — 13,245 Less: leases executed but not yet commenced — 344,202 Less: lease incentives and transfer to held for sale — 2,825 Total $ 3,624 $ 132,236 The current portion of the finance lease liability is included within other current liabilities while the non-current portion is included within other non-current liabilities on the condensed consolidated balance sheets. The associated finance lease assets are included in property and equipment, net on the condensed consolidated balance sheets. Litigation The Company is currently a party to, and may in the future be involved in, various litigation matters (including intellectual property litigation), legal claims, and government investigations. The Treasurer & Tax Collector of the City and County of San Francisco (Tax Collector) has issued a decision for fiscal years 2014 and 2015, that the Tax Collector believes the Company’s primary business activity is financial services rather than information, and accordingly, the Company would be liable for the Gross Receipts Tax and Payroll Expense Tax under the rules for financial services business activities. The Company paid the liability of $1.3 million for fiscal years 2014 and 2015 in the first quarter of 2018, as assessed by the Tax Collector, even though the Company strongly disagrees with the Tax Collector’s assessment of the Company’s primary business activity. Additionally, in connection with a tax audit for the fiscal years 2016 and 2017, the Company received a notice of tax audit deficiency with respect to San Francisco Gross Receipts Tax and Payroll Expense Tax for those years on October 16, 2019. The Company believes its position has merit and intends to vigorously pursue all available remedies. On September 6, 2019, the Company filed a lawsuit against the Tax Collector and the City and County of San Francisco in San Francisco County Superior Court for a refund of the liability for the fiscal years of 2014 and 2015. While the Company believes it has strong arguments, there is no assurance that courts will rule in the Company’s favor. Should the Company not prevail, the Company could be obligated to pay additional taxes together with any associated penalties and interest for subsequent years that in aggregate could be material. Moreover, a San Francisco ballot measure approved on November 6, 2018 increased taxes on gross receipts beginning January 1, 2019, which further increases the Company’s tax exposure. Should the Company not prevail in its legal challenge against the application of San Francisco’s Gross Receipts Tax to its business, the Company estimates that it could become liable to pay additional taxes, interest, and penalties that range from approximately $0 to $56 million in the aggregate for the fiscal years 2016, 2017, and 2018 and for the nine months ended on September 30, 2019, over and above the taxes the Company has already paid under the information classification. Additional taxes, interest, and penalties for future periods could be material as well. The Company regularly assesses the likelihood of adverse outcomes resulting from tax disputes such as this and examinations for all open years to determine the necessity and adequacy of any tax reserves. Given the uncertainty of the possible outcome, the Company has not recorded reserves for the exposure related to the dispute with the Tax Collector on San Francisco’s Gross Receipts Tax. In connection with the sale of Caviar to DoorDash, we have agreed to indemnify DoorDash for certain liabilities, including certain litigation related to Caviar, such as the Woodle and Cole cases mentioned below, that DoorDash assumed upon the closing of the sale. On May 14, 2018, Joshua Woodle, on behalf of a class of couriers who have delivered with Caviar in California, filed a lawsuit in San Francisco County Superior Court against the Company doing business as Caviar, which alleges that Caviar misclassified Mr. Woodle 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. Plaintiffs seek damages and injunctive relief. The Court compelled arbitration of Mr. Woodle’s arbitrable claims on November 5, 2018. On August 24, 2018, Mervyn Cole, on behalf of the State of California and similarly situated couriers who have delivered with Caviar in California filed a lawsuit in Los Angeles County Superior Court against the Company doing business as Caviar. The complaint alleges that Caviar misclassified Mr. Cole and other similarly situated couriers as independent contractors and, in doing so, violated certain provisions of the California Labor Code. The action is being brought as a representative action under the Private Attorneys General Act (“PAGA”). Plaintiffs seek civil penalties and injunctive relief. Given the early stage of these proceedings, it is not yet possible to reliably determine any potential liability that could result from these matters. In addition, from time to time, the Company is involved in various other litigation matters and disputes arising in the ordinary course of business, including similar claims as those referenced above, alleging misclassification of couriers as independent contractors. The Company cannot at this time fairly estimate a reasonable range of exposure, if any, of the potential liability with respect to these other matters. While the Company does not believe, at this time, that any ultimate liability resulting from any of these other matters will have a material adverse effect on the Company's results of operations, financial position, or liquidity, the Company cannot give any assurance regarding the ultimate outcome of these other matters, and their resolution could be material to the Company's operating results for any particular period.

SEGMENT AND GEOGRAPHICAL INFORM

SEGMENT AND GEOGRAPHICAL INFORMATION	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
SEGMENT AND GEOGRAPHIC INFORMATION	SEGMENT AND GEOGRAPHICAL INFORMATION Operating segments are defined as components of an enterprise for which discrete financial information is available that is evaluated regularly by the chief operating decision maker (CODM) for purposes of allocating resources and evaluating financial performance. The Company’s CODM is the chief executive officer who reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. As such, the Company’s operations constitute a single operating segment and one reportable segment. Revenue Revenue by geography is based on the billing addresses of the sellers or customers. The following table sets forth revenue by geographic area (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenue United States $ 1,200,488 $ 838,149 $ 3,233,432 $ 2,255,657 International 65,986 43,959 166,639 109,992 Total net revenue $ 1,266,474 $ 882,108 $ 3,400,071 $ 2,365,649 No individual country from the international markets contributed in excess of 10% of total revenue for the three and nine months ended September 30, 2019 and 2018 . 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 $ 570,273 $ 471,970 International 11,198 9,239 Total long-lived assets $ 581,471 $ 481,209

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	9 Months Ended
	Sep. 30, 2019
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, 2019 2018 Supplemental Cash Flow Data: Cash paid for interest $ 3,377 $ 1,945 Cash paid for income taxes 2,266 1,265 Right-of-use assets obtained in exchange for operating lease obligations 31,013 — Supplemental disclosures of non-cash investing and financing activities: Change in purchases of property and equipment in accounts payable and accrued expenses 11,402 11,004 Unpaid business combination purchase price 8,411 3,995 Fair value of common stock issued related to business combination — (140,107 ) Recovery of common stock in connection with indemnification settlement agreement 789 2,745 Fair value of common stock issued to settle the conversion of senior notes, due 2022 — (189,916 ) Fair value of shares received to settle senior note hedges, due 2022 — 189,916

DESCRIPTION OF BUSINESS AND S_2

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	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, 2018 condensed consolidated balance sheet was derived from the audited financial statements as of that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The accompanying unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company's consolidated financial position, results of operations, comprehensive income (loss), and cash flows for the interim periods. All intercompany transactions and balances have been eliminated in consolidation. The interim results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 , or for any other future annual or interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Consolidated Financial Statements and related notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 .
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, as well as related disclosure of contingent assets and liabilities. Actual results could differ from the Company’s estimates. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be materially affected. The Company bases its estimates on past experience and other assumptions that the Company believes are reasonable under the circumstances, and the Company evaluates these estimates on an ongoing basis. Estimates, judgments, and assumptions in these consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued transaction losses, valuation of the debt component of convertible senior notes, valuation of loans held for sale, goodwill, acquired intangible assets and deferred revenue, income and other taxes, operating and financing lease right-of-use assets and related liabilities, and share-based compensation.
Concentration of Credit Risk	Concentration of Credit Risk For the three and nine months ended September 30, 2019 and 2018 , the Company had no customer that accounted for greater than 10% of total net revenue. The Company had three third-party payment processors that represented approximately 46% , 34% , and 9% of settlements receivable as of September 30, 2019 . The same three parties represented approximately 45% , 33% , and 9% of settlements receivable as of December 31, 2018 . All other third-party processors were insignificant. Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, marketable debt securities, settlements receivables, customer funds, and loans held for sale. The associated risk of concentration for cash and cash equivalents and restricted cash is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed federal deposit insurance limits. The associated risk of concentration for marketable debt securities is mitigated by holding a diversified portfolio of highly rated investments. Settlements receivable are amounts due from well-established payment processing companies and normally take one or two business days to settle which mitigates the associated risk of concentration. The associated risk of concentration for loans held for sale is partially mitigated by credit evaluations that are performed prior to facilitating the offering of loans and ongoing performance monitoring of the Company’s loan customers.
Assets Held for Sale	Assets Held for Sale The Company classifies an asset group (‘asset’) as held for sale in the period that (i) it has approved and committed to a plan to sell the asset, (ii) the asset is available for immediate sale in its present condition, (iii) an active program to locate a buyer and other actions required to sell the asset have been initiated, (iv) the sale of the asset is probable and transfer of the asset is expected to qualify for recognition as a completed sale within one year (subject to certain events or circumstances), (v) the asset is being actively marketed for sale at a price that is reasonable in relation to its current fair value, and (vi) it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. The Company initially and subsequently measures a long-lived asset that is classified as held for sale at the lower of its carrying value or fair value less any costs to sell. Any loss resulting from this measurement is recognized in general and administrative expenses in the period in which the held for sale criteria are met. Conversely, gains are generally not recognized on the sale of a long-lived asset until the date of sale. Upon designation as an asset held for sale, the Company stops recording depreciation or amortization expense on the asset. The Company assesses the fair value of assets held for sale less any costs to sell at each reporting period until the asset is no longer classified as held for sale.
New Accounting Policies and Recent Accounting Pronouncements	New Accounting Policies The Company adopted Accounting Standards Codification (ASC) 842, Leases on January 1, 2019, and elected the optional transition method to apply the transition provisions from the effective date of adoption, which requires the Company to report the cumulative effect of the adoption of the standard on the date of adoption with no changes to the prior period balances. Pursuant to the practical expedients, the Company has elected not to reassess: (i) whether expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases, or, (iii) initial direct costs for any existing leases. The Company recognized $112.0 million of operating right-of-use lease assets and $135.6 million of operating lease liabilities on its consolidated balance sheet upon adoption of this standard. Additionally, the Company derecognized $149 million related to the build-to-suit asset and liability upon adoption of this standard because the Company is no longer deemed to be the owner of the related asset under construction under the new standard. Refer to Note 19 for further detail. Except for the adoption of ASC 842, there have been no material changes to the Company’s accounting policies during the nine months ended September 30, 2019 , as compared to the accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 . Recent Accounting Pronouncements Recently issued accounting pronouncements not yet adopted In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-13,Financial Instruments - Credit Losses, which requires the measurement and recognition of expected credit losses for financial assets held. It also eliminates the concept of other-than-temporary impairment and requires credit losses related to available for sale debt securities to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company intends to adopt this guidance effective January 1, 2020. The Company’s preliminary conclusion is that the new guidance will not have a material impact on the balances reported on its consolidated financial statements. The Company has also determined that allowances for credit losses associated with its available for sale debt securities would be immaterial. Upon adoption of this guidance, the Company will expand its disclosures to discuss how it develops its expected credit loss estimates, the methodology applied to estimate the allowance for credit losses, and the factors that influence the Company's estimates. For available for sale debt securities with unrealized losses where the Company concludes that an allowance for credit losses is not necessary, the Company will expand its disclosures of the associated fair value of such securities as well as the basis for conclusions that an allowance for credit losses was not necessary. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment . The new guidance eliminates the requirement to calculate the implied fair value of goodwill assuming a hypothetical purchase price allocation (i.e., Step 2 of the goodwill impairment test) to measure a goodwill impairment charge. Instead, entities will record an impairment charge based on the excess of a reporting unit’s carrying amount over its fair value, not to exceed the carrying amount of goodwill. This standard should be adopted when the Company performs its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted. The amendments should be applied on a prospective basis. The Company intends to adopt this guidance effective with its 2019 annual goodwill impairment test which it performs as of December 31. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures. In July 2018, the FASB issued ASU 2018-13, Changes to the Disclosure Requirements for Fair Value Measurement, which will remove, modify, and add disclosure requirements for fair value measurements to improve the overall usefulness of such disclosures. 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 for any removed or modified disclosure requirements. Transition is on a prospective basis for the new and modified disclosures, and on a retrospective basis for disclosures that have been eliminated. The Company currently does not intend to early adopt any portion of this disclosure guidance. The Company is currently evaluating the impact this guidance may have on the consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which is intended to align the requirements for capitalization of implementation costs incurred in a cloud computing arrangement that is a service contract with the existing guidance for internal-use software. 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 guidance provides flexibility in adoption, allowing for either retrospective adjustment or prospective adjustment for all implementation costs incurred after the date of adoption. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements and related disclosures.

REVENUE (Tables)

REVENUE (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table presents the Company's revenue disaggregated by revenue source (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenue from Contracts with Customers: Transaction-based revenue $ 816,622 $ 655,384 $ 2,248,894 $ 1,803,649 Subscription and services-based revenue 239,895 141,752 645,588 330,637 Hardware revenue 21,766 17,558 62,238 50,337 Bitcoin revenue 148,285 42,963 338,898 114,074 Revenue from other sources: Subscription and services-based revenue $ 39,906 $ 24,451 $ 104,453 $ 66,952
Schedule of Deferred Revenue	The deferred revenue balances were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Deferred revenue, beginning of the period $ 44,812 $ 27,155 $ 36,451 $ 5,893 Less: cumulative impact of the adoption of ASC 606 — — — (4,303 ) Deferred revenue, beginning of the period, as adjusted 44,812 27,155 36,451 1,590 Deferred revenue, end of the period 45,263 33,614 45,263 33,614 Deferred revenue arising from business combination — 22,800 — 22,800 Revenue recognized in the period from amounts included in deferred revenue at the beginning of the period $ 12,656 $ 10,165 $ 28,280 $ 1,539

INVESTMENTS (Tables)

INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 132,217 $ 257 $ (126 ) $ 132,348 Corporate bonds 55,399 194 (92 ) 55,501 Commercial paper 2,245 — — 2,245 Municipal securities 2,713 5 (49 ) 2,669 U.S. government securities 351,592 317 (192 ) 351,717 Foreign securities 13,214 — (38 ) 13,176 Total $ 557,380 $ 773 $ (497 ) $ 557,656 Long-term debt securities: U.S. agency securities $ 87,848 $ 219 $ (164 ) $ 87,903 Corporate bonds 185,675 286 (398 ) 185,563 Municipal securities 12,668 12 (98 ) 12,582 U.S. government securities 250,434 267 (436 ) 250,265 Foreign securities 28,264 6 (75 ) 28,195 Total $ 564,889 $ 790 $ (1,171 ) $ 564,508 The Company's short-term and long-term investments as of December 31, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 80,160 $ 32 $ (70 ) $ 80,122 Corporate bonds 109,807 80 (368 ) 109,519 Municipal securities 27,839 52 (59 ) 27,832 U.S. government securities 292,615 161 (509 ) 292,267 Foreign securities 31,263 4 (16 ) 31,251 Total $ 541,684 $ 329 $ (1,022 ) $ 540,991 Long-term debt securities: U.S. agency securities $ 114,444 $ 194 $ (78 ) $ 114,560 Corporate bonds 159,783 419 (950 ) 159,252 Municipal securities 28,453 167 (26 ) 28,594 U.S. government securities 153,743 553 (172 ) 154,124 Foreign securities 8,122 28 — 8,150 Total $ 464,545 $ 1,361 $ (1,226 ) $ 464,680
Contractual Maturities of Short-Term and Long-Term Investments	The contractual maturities of the Company's short-term and long-term investments as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 557,380 $ 557,656 Due in one to five years 564,889 564,508 Total $ 1,122,269 $ 1,122,164 The contractual maturities of the Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 223,850 $ 223,826 Total $ 223,850 $ 223,826

CUSTOMER FUNDS (Tables)

CUSTOMER FUNDS (Tables)	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Assets Underlying Customer Funds	The following table presents the assets underlying customer funds (in thousands): September 30, December 31, Cash $ 407,719 $ 158,697 Cash Equivalents: Money market funds 388 18 U.S. agency securities 21,667 39,991 U.S. government securities 6,999 35,349 Short-term debt securities: U.S. agency securities 1,654 27,291 U.S. government securities 222,172 72,671 Total $ 660,599 $ 334,017
Investments within Customer Funds	The Company's investments within customer funds as of December 31, 2018 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 27,293 $ 2 $ (4 ) $ 27,291 U.S. government securities 72,662 12 (3 ) 72,671 Total $ 99,955 $ 14 $ (7 ) $ 99,962 The Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term debt securities: U.S. agency securities $ 1,657 $ — $ (3 ) $ 1,654 U.S. government securities 222,193 39 (60 ) 222,172 Total $ 223,850 $ 39 $ (63 ) $ 223,826
Contractual Maturities of Investments within Customer Funds	The contractual maturities of the Company's short-term and long-term investments as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 557,380 $ 557,656 Due in one to five years 564,889 564,508 Total $ 1,122,269 $ 1,122,164 The contractual maturities of the Company's investments within customer funds as of September 30, 2019 are as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 223,850 $ 223,826 Total $ 223,850 $ 223,826

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 December 31, 2018 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash Equivalents: Money market funds $ 304,690 $ — $ — $ 218,109 $ — $ — U.S. agency securities — 40,410 — — 46,423 — Time deposits 10,146 — — — — — U.S. government securities 23,963 — — — — — Municipal securities — — — 86,239 — — Foreign securities — — — — 23,981 — Customer funds: Money market funds 388 — — 18 — — U.S. agency securities — 23,321 — — 67,282 — U.S. government securities 229,171 — — 108,020 — — Short-term debt securities: U.S. agency securities — 132,348 — — 80,122 — Corporate bonds — 55,501 — — 109,519 — Commercial paper — 2,245 — — — — Municipal securities — 2,669 — — 27,832 — U.S. government securities 351,717 — — 292,267 — — Foreign securities — 13,176 — — 31,251 — Long-term debt securities: U.S. agency securities — 87,903 — — 114,560 — Corporate bonds — 185,563 — — 159,252 — Municipal securities — 12,582 — — 28,594 — U.S. government securities 250,265 — — 154,124 — — Foreign securities — 28,195 — — 8,150 — Other: Marketable equity investment 28,875 — — 45,342 — — Total $ 1,199,215 $ 583,913 $ — $ 904,119 $ 696,966 $ — The estimated fair value and carrying value of loans held for sale is as follows (in thousands): September 30, 2019 December 31, 2018 Carrying Value Fair Value (Level 3) Carrying Value Fair Value (Level 3) Loans held for sale $ 120,776 $ 126,218 $ 89,974 $ 93,064 Total $ 120,776 $ 126,218 $ 89,974 $ 93,064 September 30, 2019 December 31, 2018 Carrying Value Fair Value (Level 2) Carrying Value Fair Value (Level 2) 2023 Notes $ 740,921 $ 961,092 $ 718,522 $ 901,468 2022 Notes 187,948 575,661 181,173 515,693 Total $ 928,869 $ 1,536,753 $ 899,695 $ 1,417,161

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	The following is a summary of property and equipment, less accumulated depreciation and amortization (in thousands): September 30, December 31, Leasehold improvements $ 108,980 $ 107,611 Computer equipment 91,464 80,093 Capitalized software 76,656 58,908 Office furniture and equipment 23,284 20,699 300,384 267,311 Less: Accumulated depreciation and amortization (166,350 ) (124,909 ) Property and equipment, net $ 134,034 $ 142,402

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of Assets Acquired and Liabilities Assumed	The table below summarizes the consideration paid for Weebly and the preliminary assessment of the fair value of the assets acquired and liabilities assumed at the closing date (in thousands, except share data). Consideration: Cash $ 132,432 Stock (2,418,271 shares of Class A common stock) 140,107 $ 272,539 Recognized amounts of identifiable assets acquired and liabilities assumed: Current assets (inclusive of cash acquired of $25,758) $ 46,978 Intangible customer assets 42,700 Intangible technology assets 14,900 Intangible trade name 11,300 Intangible other assets 961 Total liabilities assumed (including deferred revenue of $22,800) (37,509 ) Total identifiable net assets acquired 79,330 Goodwill 193,209 Total $ 272,539

ASSETS AND LIABILITIES HELD F_2

ASSETS AND LIABILITIES HELD FOR SALE (Tables)	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Carrying Values of the Assets and Liabilities Held for Sale	The following table summarizes the carrying values of the assets and liabilities classified as held for sale as of September 30, 2019 (in thousands): Balance at September 30, 2019 Assets held for sale Intangible assets $ 7,582 Goodwill 4,186 Property and equipment, net 1,098 Operating lease right-of-use assets 791 Total assets held for sale, included within other assets 13,657 Liabilities held for sale Operating lease liabilities, current 754 Net assets held for sale $ 12,903

GOODWILL (Tables)

GOODWILL (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Change in Carrying Value of Goodwill	The change in carrying value of goodwill in the period was as follows (in thousands): Balance at December 31, 2018 $ 261,705 Acquisitions 10,832 Transfer to assets held for sale (Note 8) (4,186 ) Other adjustments (2,377 ) Balance at September 30, 2019 $ 265,974

ACQUIRED INTANGIBLE ASSETS (Tab

ACQUIRED INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite Lived Intangible Assets	The changes to the carrying value of intangible assets were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Acquired intangible assets, net, beginning of the period $ 84,216 $ 85,514 $ 77,102 $ 14,334 Acquisitions — — 14,559 75,871 Amortization expense (3,841 ) (4,384 ) (11,286 ) (9,075 ) Transfer to assets held for sale (Note 8) (7,582 ) — (7,582 ) — Acquired intangible assets, net, end of the period $ 72,793 $ 81,130 $ 72,793 $ 81,130 The following table presents the detail of acquired intangible assets as of the periods presented (in thousands): Balance at September 30, 2019 Cost Accumulated Amortization Net Technology assets 54,630 (30,682 ) 23,948 Customer assets 44,045 (6,089 ) 37,956 Trade name 11,300 (3,767 ) 7,533 Other 5,299 (1,943 ) 3,356 Total $ 115,274 $ (42,481 ) $ 72,793 Balance at December 31, 2018 Cost Accumulated Amortization Net Technology assets $ 45,978 $ (28,420 ) $ 17,558 Customer assets 57,109 (8,068 ) 49,041 Trade name 11,300 (1,648 ) 9,652 Other 2,246 (1,395 ) 851 Total $ 116,633 $ (39,531 ) $ 77,102
Schedule of Future Amortization Expense of Intangible Assets	The total estimated future amortization expense of these intangible assets as of September 30, 2019 is as follows (in thousands): 2019 (remaining 3 months) $ 3,714 2020 12,800 2021 11,829 2022 10,134 2023 8,917 Thereafter 25,399 Total $ 72,793

OTHER CONSOLIDATED BALANCE SH_3

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) (Tables)	9 Months Ended
	Sep. 30, 2019
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, Inventory, net $ 44,690 $ 28,627 Processing costs receivable 63,652 46,102 Prepaid expenses 17,341 21,782 Accounts receivable, net 37,564 22,393 Assets held for sale (Note 8) 13,657 — Other 38,902 46,062 Total $ 215,806 $ 164,966
Schedule of Accrued Expenses	The following table presents the detail of accrued expenses (in thousands): September 30, December 31, Accrued facilities expenses $ 21,302 $ 13,040 Accrued payroll 21,313 9,612 Accrued advertising and other marketing 20,070 12,201 Processing costs payable 13,199 12,683 Accrued non income tax liabilities 8,383 9,503 Other accrued liabilities 39,738 25,315 Total $ 124,005 $ 82,354
Schedule of Other Current Liabilities	The following table presents the detail of other current liabilities (in thousands): September 30, December 31, Accounts payable $ 37,156 $ 36,416 Deferred revenue, current 39,025 31,474 Square Capital payable (i) 5,851 6,092 Square Payroll payable (ii) 13,304 7,534 Other 12,731 17,637 Total $ 108,067 $ 99,153 (i) Square Capital payable represents unpaid amounts arising from the purchase of loans or loan repayments collected on behalf of third parties. (ii) Square Payroll payable represents amounts received from Square Payroll product customers that will be utilized to settle the customers' employee payroll and related obligations.

OTHER CONSOLIDATED BALANCE SH_4

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) (Tables)	9 Months Ended
	Sep. 30, 2019
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, Marketable equity investment (i) $ 28,875 $ 45,342 Non-current lease prepayments 34,199 — Other 18,252 13,051 Total $ 81,326 $ 58,393 (i) This balance represents the Company's investment in Class B common shares of Eventbrite, Inc. (Eventbrite). The investment is carried at fair value with changes in fair value being recorded on the consolidated statement of operations. During the three and nine months ended September 30, 2019 , the Company recorded a gain of $ 2.5 million and a loss of $16.5 million , respectively, to other expense (income), net on the consolidated statements of operations arising from revaluation of this investment.
Schedule of Other Non-Current Liabilities	The following table presents the detail of other non-current liabilities (in thousands): September 30, December 31, Statutory liabilities (i) $ 51,623 $ 54,748 Deferred rent, non-current (ii) — 23,003 Deferred revenue, non-current 6,238 4,977 Other 12,622 10,558 Total $ 70,483 $ 93,286 (i) Statutory liabilities represent loss contingencies that may arise from the Company's interpretation and application of certain guidelines and rules issued by various federal, state, local, and foreign regulatory authorities. (ii) The adoption of ASC 842 on January 1, 2019 resulted in the reclassification of deferred rent as an offset to right-of-use lease assets.

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Net Carrying Amount of Convertible Notes	The net carrying amount of the Notes were as follows (in thousands): Principal outstanding Unamortized debt discount Unamortized debt issuance costs Net carrying value September 30, 2019 2023 Notes $ 862,500 $ (117,932 ) $ (3,647 ) $ 740,921 2022 Notes 211,726 (21,400 ) (2,378 ) 187,948 Total $ 1,074,226 $ (139,332 ) $ (6,025 ) $ 928,869 December 31, 2018 2023 Notes $ 862,500 $ (138,924 ) $ (5,054 ) $ 718,522 2022 Notes 211,728 (27,569 ) (2,986 ) 181,173 $ 1,074,228 $ (166,493 ) $ (8,040 ) $ 899,695 The net carrying amount of the equity component of the 2023 Notes and 2022 Notes were as follows (in thousands): Amount allocated to conversion option Less: allocated issuance costs Equity component, net September 30, 2019 and December 31, 2018 2023 Notes $ 155,250 $ (1,231 ) $ 154,019 2022 Notes 41,481 (1,108 ) 40,373 Total $ 196,731 $ (2,339 ) $ 194,392
Interest Expense on Convertible Notes	The Company recognized interest expense on the Notes as follows (in thousands, except for percentages): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Contractual interest expense $ 1,277 $ 1,469 $ 3,831 $ 2,732 Amortization of debt discount and issuance costs 9,843 11,627 29,176 22,850 Total $ 11,120 $ 13,096 $ 33,007 $ 25,582

ACCRUED TRANSACTION LOSSES (Tab

ACCRUED TRANSACTION LOSSES (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 2018 2019 2018 Accrued transaction losses, beginning of the period $ 39,630 $ 29,207 $ 33,682 $ 26,893 Provision for transaction losses 18,225 20,449 60,223 48,794 Charge-offs to accrued transaction losses (20,436 ) (14,324 ) (56,486 ) (40,355 ) Accrued transaction losses, end of the period $ 37,419 $ 35,332 $ 37,419 $ 35,332

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity	A summary of stock option activity for the nine months ended September 30, 2019 is as follows (in thousands, except share and per share data): Number of Stock Options Outstanding Weighted Weighted Aggregate Balance at December 31, 2018 33,152,881 $ 9.52 5.45 $ 1,543,793 Granted 1,184,657 72.15 Exercised (7,881,289 ) 7.97 Forfeited (136,772 ) 11.70 Balance at September 30, 2019 26,319,477 $ 12.80 5.23 $ 1,305,789 Options exercisable as of September 30, 2019 24,136,540 $ 9.40 4.92 $ 1,269,509
Schedule of Restricted Stock Awards and Restricted Stock Units Activity	Activity related to RSAs and RSUs during the nine months ended September 30, 2019 is set forth below: Number of Weighted Unvested as of December 31, 2018 17,934,728 $ 31.34 Granted 5,735,224 73.29 Vested (6,016,950 ) 29.05 Forfeited (1,727,904 ) 35.90 Unvested as of September 30, 2019 15,925,098 $ 46.82
Schedule of Fair Value Assumptions for Options	The fair value of stock options granted was estimated using the following weighted-average assumptions: Nine Months Ended September 30, 2019 2018 Dividend yield — % — % Risk-free interest rate 2.48 % 2.92 % Expected volatility 39.52 % 30.87 % Expected term (years) 6.05 6.19
Summary of the Effect of Share-Based Compensation on the Condensed Consolidated Statements of Operations	The following table summarizes the effects of share-based compensation on the Company's condensed consolidated statements of operations (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Cost of revenue $ 38 $ 18 $ 88 $ 79 Product development 56,321 39,525 155,114 103,813 Sales and marketing 6,269 6,108 20,304 16,703 General and administrative 14,798 13,262 42,474 37,261 Total $ 77,426 $ 58,913 $ 217,980 $ 157,856

NET INCOME (LOSS) PER SHARE (Ta

NET INCOME (LOSS) PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net income (loss) per share (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: Net income (loss) $ 29,397 $ 19,643 $ (15,494 ) $ (10,249 ) Denominator: Basic shares: Weighted-average common shares outstanding 427,906 410,095 423,957 403,577 Weighted-average unvested shares (782 ) (405 ) (718 ) (597 ) Weighted-average shares used to compute basic net loss per share 427,124 409,690 423,239 402,980 Diluted shares: Stock options and restricted stock units 28,549 47,175 — — Convertible senior notes — 6,409 — — Common stock warrants 10,372 11,422 — — Employee stock purchase plan 54 219 — — Weighted-average shares used to compute diluted net income (loss) per share 466,099 474,915 423,239 402,980 Net income (loss) per share: Basic $ 0.07 $ 0.05 $ (0.04 ) $ (0.03 ) Diluted $ 0.06 $ 0.04 $ (0.04 ) $ (0.03 )
Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Income (Loss) Per Share	The following potential common shares were excluded from the calculation of diluted net income (loss) per share because their effect would have been anti-dilutive for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Stock options and restricted stock units 15,113 12,079 46,045 62,822 Common stock warrants 19,880 18,830 30,252 24,387 Convertible senior notes 20,305 23,415 20,305 24,276 Unvested shares 782 405 718 597 Employee stock purchase plan 189 26 217 207 Total anti-dilutive securities 56,269 54,755 97,537 112,289

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Lease Expense Components and Other Information Related to Leases	The components of lease expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 Fixed operating lease costs $ 7,449 $ 21,626 Variable operating lease costs 1,646 3,871 Sublease income (1,468 ) (1,570 ) Finance lease costs Amortization of finance right-of-use assets 1,284 3,861 Interest on finance lease liabilities — — Total lease costs $ 8,911 $ 27,788 For the periods presented, costs associated with short-term leases were not material. Other information related to leases was as follows: September 30, 2019 Weighted Average Remaining Lease Term: Operating leases 4.5 years Finance leases 0.9 years Weighted Average Discount Rate: Operating leases 4 % Finance leases — % Cash flows related to leases were as follows (in thousands): Nine Months Ended September 30, 2019 Cash flows from operating activities: Payments for operating lease liabilities $ 24,580 Cash flows from financing activities: Principal payments on finance lease obligation $ 3,860 Supplemental Cash Flow Data: Right-of-use assets obtained in exchange for operating lease obligations $ 31,013
Future Minimum Lease Payments under Non-Cancelable Operating Leases	Future minimum lease payments under non-cancelable operating leases (with initial lease terms in excess of one year) and future minimum finance lease payments as of September 30, 2019 are as follows (in thousands): Finance Operating Year: 2019 (remaining 3 months) $ 1,178 $ 5,942 2020 2,446 40,388 2021 — 59,459 2022 — 61,005 2023 — 54,842 Thereafter — 270,872 Total $ 3,624 $ 492,508 Less: amount representing interest — 13,245 Less: leases executed but not yet commenced — 344,202 Less: lease incentives and transfer to held for sale — 2,825 Total $ 3,624 $ 132,236
Future Minimum Finance Lease Payments	Future minimum lease payments under non-cancelable operating leases (with initial lease terms in excess of one year) and future minimum finance lease payments as of September 30, 2019 are as follows (in thousands): Finance Operating Year: 2019 (remaining 3 months) $ 1,178 $ 5,942 2020 2,446 40,388 2021 — 59,459 2022 — 61,005 2023 — 54,842 Thereafter — 270,872 Total $ 3,624 $ 492,508 Less: amount representing interest — 13,245 Less: leases executed but not yet commenced — 344,202 Less: lease incentives and transfer to held for sale — 2,825 Total $ 3,624 $ 132,236

SEGMENT AND GEOGRAPHICAL INFO_2

SEGMENT AND GEOGRAPHICAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Revenue by Geographic Area	Revenue by geography is based on the billing addresses of the sellers or customers. The following table sets forth revenue by geographic area (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenue United States $ 1,200,488 $ 838,149 $ 3,233,432 $ 2,255,657 International 65,986 43,959 166,639 109,992 Total net revenue $ 1,266,474 $ 882,108 $ 3,400,071 $ 2,365,649
Long-lived Assets by Geographic Area	The following table sets forth long-lived assets by geographic area (in thousands): September 30, December 31, Long-lived assets United States $ 570,273 $ 471,970 International 11,198 9,239 Total long-lived assets $ 581,471 $ 481,209

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 2018 Supplemental Cash Flow Data: Cash paid for interest $ 3,377 $ 1,945 Cash paid for income taxes 2,266 1,265 Right-of-use assets obtained in exchange for operating lease obligations 31,013 — Supplemental disclosures of non-cash investing and financing activities: Change in purchases of property and equipment in accounts payable and accrued expenses 11,402 11,004 Unpaid business combination purchase price 8,411 3,995 Fair value of common stock issued related to business combination — (140,107 ) Recovery of common stock in connection with indemnification settlement agreement 789 2,745 Fair value of common stock issued to settle the conversion of senior notes, due 2022 — (189,916 ) Fair value of shares received to settle senior note hedges, due 2022 — 189,916

DESCRIPTION OF BUSINESS AND S_3

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)customer	Sep. 30, 2018customer	Sep. 30, 2019USD ($)customerthird_party_processor	Sep. 30, 2018customer	Dec. 31, 2018USD ($)third_party_processor	Jan. 01, 2019USD ($)
Concentration Risk [Line Items]
Operating lease right-of-use assets	$ 108,670		$ 108,670
Operating lease liability	132,236		132,236
Derecognition of build-to-suit lease asset	0		0		$ (149,000)
Derecognition of build-to-suit lease liability	$ 0		$ 0		$ (149,000)
Total Net Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers accounting for greater than 10% of total net revenue | customer	0	0	0	0
Settlements Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Number of third party processors | third_party_processor			3		3
Settlements Receivable | Credit Concentration Risk | Third Party Processor One
Concentration Risk [Line Items]
Concentration risk, settlements receivable			46.00%		45.00%
Settlements Receivable | Credit Concentration Risk | Third Party Processor Two
Concentration Risk [Line Items]
Concentration risk, settlements receivable			34.00%		33.00%
Settlements Receivable | Credit Concentration Risk | Third Party Processor Three
Concentration Risk [Line Items]
Concentration risk, settlements receivable			9.00%		9.00%
Minimum
Concentration Risk [Line Items]
Settlements receivable period			1 day
Maximum
Concentration Risk [Line Items]
Settlements receivable period			2 days
Accounting Standards Update 2016-02
Concentration Risk [Line Items]
Operating lease right-of-use assets						$ 112,000
Operating lease liability						135,600
Derecognition of build-to-suit lease asset						149,000
Derecognition of build-to-suit lease liability						$ 149,000

REVENUE - Disaggregation of Rev

REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Transaction-based revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 816,622	$ 655,384	$ 2,248,894	$ 1,803,649
Subscription and services-based revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	239,895	141,752	645,588	330,637
Revenues from other sources	39,906	24,451	104,453	66,952
Hardware revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	21,766	17,558	62,238	50,337
Bitcoin revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 148,285	$ 42,963	$ 338,898	$ 114,074

REVENUE - Deferred Revenue (Det

REVENUE - Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred revenue	$ 45,263	$ 33,614	$ 45,263	$ 33,614	$ 44,812	$ 36,451	$ 27,155	$ 1,590
Deferred revenue arising from business combination	0	22,800	0	22,800
Revenue recognized in the period from amounts included in deferred revenue at the beginning of the period	$ 12,656	$ 10,165	$ 28,280	$ 1,539
Balances without adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred revenue					44,812	36,451	27,155	5,893
Accounting Standards Update 2014-09 | Effect of change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred revenue					$ 0	$ 0	$ 0	$ (4,303)

INVESTMENTS - Short-Term and Lo

INVESTMENTS - Short-Term and Long-Term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,122,269
Fair Value	1,122,164
Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	557,380	$ 541,684
Gross Unrealized Gains	773	329
Gross Unrealized Losses	(497)	(1,022)
Fair Value	557,656	540,991
Long-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	564,889	464,545
Gross Unrealized Gains	790	1,361
Gross Unrealized Losses	(1,171)	(1,226)
Fair Value	564,508	464,680
U.S. agency securities | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	132,217	80,160
Gross Unrealized Gains	257	32
Gross Unrealized Losses	(126)	(70)
Fair Value	132,348	80,122
U.S. agency securities | Long-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	87,848	114,444
Gross Unrealized Gains	219	194
Gross Unrealized Losses	(164)	(78)
Fair Value	87,903	114,560
Corporate bonds | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	55,399	109,807
Gross Unrealized Gains	194	80
Gross Unrealized Losses	(92)	(368)
Fair Value	55,501	109,519
Corporate bonds | Long-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	185,675	159,783
Gross Unrealized Gains	286	419
Gross Unrealized Losses	(398)	(950)
Fair Value	185,563	159,252
Commercial paper | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,245
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	2,245
Municipal securities | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,713	27,839
Gross Unrealized Gains	5	52
Gross Unrealized Losses	(49)	(59)
Fair Value	2,669	27,832
Municipal securities | Long-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	12,668	28,453
Gross Unrealized Gains	12	167
Gross Unrealized Losses	(98)	(26)
Fair Value	12,582	28,594
U.S. government securities | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	351,592	292,615
Gross Unrealized Gains	317	161
Gross Unrealized Losses	(192)	(509)
Fair Value	351,717	292,267
U.S. government securities | Long-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	250,434	153,743
Gross Unrealized Gains	267	553
Gross Unrealized Losses	(436)	(172)
Fair Value	250,265	154,124
Foreign securities | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	13,214	31,263
Gross Unrealized Gains	0	4
Gross Unrealized Losses	(38)	(16)
Fair Value	13,176	31,251
Foreign securities | Long-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,264	8,122
Gross Unrealized Gains	6	28
Gross Unrealized Losses	(75)	0
Fair Value	$ 28,195	$ 8,150

INVESTMENTS - Contractual Matur

INVESTMENTS - Contractual Maturities of Short-Term and Long-Term Investments (Details) $ in Thousands	Sep. 30, 2019USD ($)
Amortized Cost
Due in one year or less	$ 557,380
Due in one to five years	564,889
Amortized Cost	1,122,269
Fair Value
Due in one year or less	557,656
Due in one to five years	564,508
Fair Value	$ 1,122,164

CUSTOMER FUNDS - Assets Underly

CUSTOMER FUNDS - Assets Underlying Customer Funds (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Customer funds	$ 660,599	$ 334,017
U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Customer funds	1,654	27,291
U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Customer funds	222,172	72,671
Cash
Debt Securities, Available-for-sale [Line Items]
Customer funds	407,719	158,697
Cash Equivalents | Money market funds
Debt Securities, Available-for-sale [Line Items]
Customer funds	388	18
Cash Equivalents | U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Customer funds	21,667	39,991
Cash Equivalents | U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Customer funds	$ 6,999	$ 35,349

CUSTOMER FUNDS - Investments wi

CUSTOMER FUNDS - Investments within Customer Funds (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,122,269
Fair Value	1,122,164
Customer funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	223,850	$ 99,955
Gross Unrealized Gains	39	14
Gross Unrealized Losses	(63)	(7)
Fair Value	223,826	99,962
Customer funds | U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,657	27,293
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(3)	(4)
Fair Value	1,654	27,291
Customer funds | U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	222,193	72,662
Gross Unrealized Gains	39	12
Gross Unrealized Losses	(60)	(3)
Fair Value	$ 222,172	$ 72,671

CUSTOMER FUNDS - Contractual Ma

CUSTOMER FUNDS - Contractual Maturities of Investments within Customer Funds (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Amortized Cost
Due in one year or less	$ 557,380
Amortized Cost	1,122,269
Fair Value
Due in one year or less	557,656
Fair Value	1,122,164
Customer funds
Amortized Cost
Due in one year or less	223,850
Amortized Cost	223,850	$ 99,955
Fair Value
Due in one year or less	223,826
Fair Value	$ 223,826	$ 99,962

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Customer funds	$ 660,599	$ 334,017
Short-term debt securities	557,656	540,991
Long-term debt securities	564,508	464,680
Marketable equity investment	28,875	45,342
U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Customer funds	1,654	27,291
U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Customer funds	222,172	72,671
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investment	28,875	45,342
Total	1,199,215	904,119
Fair Value, Measurements, Recurring | Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	304,690	218,109
Customer funds	388	18
Fair Value, Measurements, Recurring | Level 1 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Customer funds	0	0
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 1 | Time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	10,146	0
Fair Value, Measurements, Recurring | Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt securities	0	0
Long-term debt 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 debt 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]
Cash equivalents	23,963	0
Customer funds	229,171	108,020
Short-term debt securities	351,717	292,267
Long-term debt securities	250,265	154,124
Fair Value, Measurements, Recurring | Level 1 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	86,239
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investment	0	0
Total	583,913	696,966
Fair Value, Measurements, Recurring | Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Customer funds	0	0
Fair Value, Measurements, Recurring | Level 2 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	40,410	46,423
Customer funds	23,321	67,282
Short-term debt securities	132,348	80,122
Long-term debt securities	87,903	114,560
Fair Value, Measurements, Recurring | Level 2 | Time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Measurements, Recurring | Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt securities	55,501	109,519
Long-term debt securities	185,563	159,252
Fair Value, Measurements, Recurring | Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term debt securities	2,245	0
Fair Value, Measurements, Recurring | Level 2 | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Customer funds	0	0
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 2 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term debt securities	2,669	27,832
Long-term debt securities	12,582	28,594
Fair Value, Measurements, Recurring | Level 2 | Foreign securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	23,981
Short-term debt securities	13,176	31,251
Long-term debt securities	28,195	8,150
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investment	0	0
Total	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 equivalents	0	0
Customer funds	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Customer funds	0	0
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	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 debt securities	0	0
Long-term debt 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 debt 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]
Cash equivalents	0	0
Customer funds	0	0
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term debt securities	0	0
Long-term debt securities	0	0
Fair Value, Measurements, Recurring | Level 3 | Foreign securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term debt securities	0	0
Long-term debt securities	$ 0	$ 0

FAIR VALUE OF FINANCIAL INSTR_4

FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value of Convertible Senior Notes (Details) - Level 2 - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	$ 928,869	$ 899,695
Fair Value (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	1,536,753	1,417,161
2023 Notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	740,921	718,522
2023 Notes | Fair Value (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	961,092	901,468
2022 Notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	187,948	181,173
2022 Notes | Fair Value (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	$ 575,661	$ 515,693

FAIR VALUE OF FINANCIAL INSTR_5

FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value of Loans Held for Sale (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Carrying Value | Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	$ 120,776		$ 120,776		$ 89,974
Fair Value (Level 3) | Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	126,218		126,218		$ 93,064
Loans Receivable Held-For-Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Excess amortized cost over fair value of loans	$ 5,300	$ 3,300	$ 18,400	$ 9,000

PROPERTY AND EQUIPMENT, NET (De

PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 300,384		$ 300,384		$ 267,311
Less: Accumulated depreciation and amortization	(166,350)		(166,350)		(124,909)
Property and equipment, net	134,034		134,034		142,402
Depreciation and amortization expense	15,300	$ 11,700	45,600	$ 29,200
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	108,980		108,980		107,611
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	91,464		91,464		80,093
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	76,656		76,656		58,908
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 23,284		$ 23,284		$ 20,699

ACQUISITIONS - Narrative (Detai

ACQUISITIONS - Narrative (Details) - USD ($) $ in Thousands	May 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired		$ 20,372	$ 112,399
Weebly, Inc.
Business Acquisition [Line Items]
Percent of outstanding shares acquired	100.00%
Cash consideration	$ 132,432
Equity consideration (in shares)	2,418,271
Equity consideration fair value	$ 140,107
Payment to settle outstanding vested and unvested employee options	17,700
Post-combination compensation expense	$ 2,600
Goodwill adjustment to purchase price allocation		3,700
Tax liabilities adjustment to purchase price allocation		4,700
Cash withheld for indemnification		$ 19,400
Shares withheld for indemnification (in shares)		363,266
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired		$ 20,400

ACQUISITIONS - Schedule of Asse

ACQUISITIONS - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	May 31, 2018	Sep. 30, 2019	Dec. 31, 2018
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 265,974	$ 261,705
Weebly, Inc.
Consideration:
Cash	$ 132,432
Stock (2,418,271 shares of Class A common stock)	$ 140,107
Shares of Class A common stock (in shares)	2,418,271
Total consideration	$ 272,539
Recognized amounts of identifiable assets acquired and liabilities assumed:
Current assets (inclusive of cash acquired of $25,758)	46,978
Cash acquired	25,758
Total liabilities assumed (including deferred revenue of $22,800)	(37,509)
Deferred revenue	22,800
Total identifiable net assets acquired	79,330
Goodwill	193,209
Total	272,539
Weebly, Inc. | Intangible customer assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	42,700
Weebly, Inc. | Intangible technology assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	14,900
Weebly, Inc. | Intangible trade name
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	11,300
Weebly, Inc. | Intangible other assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	$ 961

ASSETS AND LIABILITIES HELD F_3

ASSETS AND LIABILITIES HELD FOR SALE - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Caviar Business | Assets, Total
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Concentration risk (less than)	5.00%
Caviar Business | Revenue Benchmark
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Concentration risk (less than)	5.00%
Subsequent Event | Caviar Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross proceeds received for sale of business		$ 410
Cash received for sale of business		310
Value of preferred stock received for sale of business		$ 100

ASSETS AND LIABILITIES HELD F_4

ASSETS AND LIABILITIES HELD FOR SALE - Carrying Values of Assets and Liabilities Held for Sale (Details) - Caviar Business - Disposal Group, Held-for-sale, Not Discontinued Operations $ in Thousands	Sep. 30, 2019USD ($)
Assets held for sale
Intangible assets	$ 7,582
Goodwill	4,186
Property and equipment, net	1,098
Operating lease right-of-use assets	791
Total assets held for sale, included within other assets	13,657
Liabilities held for sale
Operating lease liabilities, current	754
Net assets held for sale	$ 12,903

GOODWILL (Details)

GOODWILL (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 261,705,000
Acquisitions			10,832,000
Transfer to assets held for sale			(4,186,000)
Other adjustments			(2,377,000)
Goodwill, ending balance	$ 265,974,000		265,974,000
Goodwill, impairment charges	$ 0	$ 0	$ 0	$ 0

ACQUIRED INTANGIBLE ASSETS - Sc

ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 115,274		$ 116,633
Accumulated Amortization	(42,481)		(39,531)
Net	72,793	$ 84,216	77,102	$ 81,130	$ 85,514	$ 14,334
Technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	54,630		45,978
Accumulated Amortization	(30,682)		(28,420)
Net	23,948		17,558
Customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	44,045		57,109
Accumulated Amortization	(6,089)		(8,068)
Net	37,956		49,041
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	11,300		11,300
Accumulated Amortization	(3,767)		(1,648)
Net	7,533		9,652
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	5,299		2,246
Accumulated Amortization	(1,943)		(1,395)
Net	$ 3,356		$ 851

ACQUIRED INTANGIBLE ASSETS - N

ACQUIRED INTANGIBLE ASSETS - Narrative (Details)	9 Months Ended
	Sep. 30, 2019
Technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	5 years
Customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	12 years
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	4 years

ACQUIRED INTANGIBLE ASSETS - Ch

ACQUIRED INTANGIBLE ASSETS - Change in Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Finite-lived Intangible Assets [Roll Forward]
Acquired intangible assets, net, beginning of the period	$ 84,216	$ 85,514	$ 77,102	$ 14,334
Acquisitions	0	0	14,559	75,871
Amortization expense	(3,841)	(4,384)	(11,286)	(9,075)
Transfer to assets held for sale	(7,582)	0	(7,582)	0
Acquired intangible assets, net, end of the period	$ 72,793	$ 81,130	$ 72,793	$ 81,130

ACQUIRED INTANGIBLE ASSETS - F

ACQUIRED INTANGIBLE ASSETS - Future Amortization Expense of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
2019 (remaining 3 months)	$ 3,714
2020	12,800
2021	11,829
2022	10,134
2023	8,917
Thereafter	25,399
Net	$ 72,793	$ 84,216	$ 77,102	$ 81,130	$ 85,514	$ 14,334

OTHER CONSOLIDATED BALANCE SH_5

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventory, net	$ 44,690	$ 28,627
Processing costs receivable	63,652	46,102
Prepaid expenses	17,341	21,782
Accounts receivable, net	37,564	22,393
Assets held for sale	13,657	0
Other	38,902	46,062
Total	$ 215,806	$ 164,966

OTHER CONSOLIDATED BALANCE SH_6

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued facilities expenses	$ 21,302	$ 13,040
Accrued payroll	21,313	9,612
Accrued advertising and other marketing	20,070	12,201
Processing costs payable	13,199	12,683
Accrued non income tax liabilities	8,383	9,503
Other accrued liabilities	39,738	25,315
Total	$ 124,005	$ 82,354

OTHER CONSOLIDATED BALANCE SH_7

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (CURRENT) - Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts payable	$ 37,156	$ 36,416
Deferred revenue, current	39,025	31,474
Square Capital payable	5,851	6,092
Square Payroll payable	13,304	7,534
Other	12,731	17,637
Total	$ 108,067	$ 99,153

OTHER CONSOLIDATED BALANCE SH_8

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) - Other Non-Current Assets (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Marketable equity investment	$ 28,875	$ 28,875		$ 45,342
Non-current lease prepayments	34,199	34,199		0
Other	18,252	18,252		13,051
Total	81,326	81,326		$ 58,393
Gain (loss) on equity investment	$ 2,500	$ (16,467)	$ 36,908

OTHER CONSOLIDATED BALANCE SH_9

OTHER CONSOLIDATED BALANCE SHEET COMPONENTS (NON-CURRENT) - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Statutory liabilities	$ 51,623	$ 54,748
Deferred rent, non-current	0	23,003
Deferred revenue, non-current	6,238	4,977
Other	12,622	10,558
Total	$ 70,483	$ 93,286

INDEBTEDNESS - Revolving Credit

INDEBTEDNESS - Revolving Credit Facility Narrative (Details) - Revolving Credit Facility - Line of Credit - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 30, 2015	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 375,000,000
Administrative agent fee	$ 100,000
Unused commitment fee percentage	0.15%
Amounts drawn to date		$ 0		$ 0
Remaining borrowing capacity		375,000,000		375,000,000
Unused commitment fees		$ 100,000	$ 400,000	$ 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%

INDEBTEDNESS - Convertible Seni

INDEBTEDNESS - Convertible Senior Notes Narrative (Details) $ / shares in Units, shares in Millions	Dec. 31, 2018USD ($)	May 25, 2018USD ($)day$ / shares	Mar. 06, 2017USD ($)day$ / shares	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)shares
Debt Instrument [Line Items]
Principal payment on conversion of senior notes				$ 0	$ 70,047,000
Loss on extinguishment of long-term debt				0	$ 1,625,000
Convertible Debt
Debt Instrument [Line Items]
Conversion price (in USD per share) | $ / shares		$ 77.85	$ 22.95
Carrying amount of equity component	$ 194,392,000			194,392,000		$ 194,392,000
Issuance costs attributable to the liability component	8,040,000			6,025,000		8,040,000
Convertible Debt | 2023 Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 862,500,000
Interest rate		0.50%
Conversion rate		0.0128456
Conversion price (in USD per share) | $ / shares		$ 77.85
Carrying amount of equity component	154,019,000	$ 155,300,000		$ 154,019,000		154,019,000
Effective interest rate of the liability component		4.69%		4.69%
Discounts and commissions payable		$ 6,000,000
Third party offering costs		800,000
Issuance costs attributable to the liability component	5,054,000	$ 5,600,000		$ 3,647,000		5,054,000
Convertible Debt | 2023 Notes | Debt Instrument, Conversion Term One
Debt Instrument [Line Items]
Threshold trading days | day		20
Threshold consecutive trading days | day		30
Threshold percentage of stock price trigger		130.00%
Convertible Debt | 2023 Notes | Debt Instrument Conversion Term Two
Debt Instrument [Line Items]
Threshold trading days | day		5
Threshold consecutive trading days | day		5
Threshold percentage of stock price trigger		98.00%
Convertible Debt | 2022 Notes
Debt Instrument [Line Items]
Aggregate principal amount			$ 440,000,000
Interest rate			0.375%
Conversion rate			0.0435749
Conversion price (in USD per share) | $ / shares			$ 22.95
Carrying amount of equity component	40,373,000		$ 86,200,000	$ 40,373,000		40,373,000
Effective interest rate of the liability component			5.34%	5.34%
Discounts and commissions payable			$ 11,000,000
Third party offering costs			800,000
Issuance costs attributable to the liability component	2,986,000		$ 9,400,000	$ 2,378,000		2,986,000
Notes converted						228,300,000
Principal payment on conversion of senior notes						$ 219,400,000
Shares issued upon conversion (in shares) | shares						7.3
Loss on extinguishment of long-term debt	5,000,000
Reduction to additional paid in capital	$ 21,000,000
Convertible Debt | 2022 Notes | Debt Instrument, Conversion Term One
Debt Instrument [Line Items]
Threshold trading days | day			20
Threshold consecutive trading days | day			30
Threshold percentage of stock price trigger			130.00%
Convertible Debt | 2022 Notes | Debt Instrument Conversion Term Two
Debt Instrument [Line Items]
Threshold trading days | day			5
Threshold consecutive trading days | day			5
Threshold percentage of stock price trigger			98.00%

INDEBTEDNESS - Net Carrying Amo

INDEBTEDNESS - Net Carrying Amount of Convertible Notes (Details) - Convertible Debt - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	May 25, 2018	Mar. 06, 2017
Debt Instrument [Line Items]
Principal outstanding	$ 1,074,226	$ 1,074,228
Unamortized debt discount	(139,332)	(166,493)
Unamortized debt issuance costs	(6,025)	(8,040)
Net carrying value	928,869	899,695
2023 Notes
Debt Instrument [Line Items]
Principal outstanding	862,500	862,500
Unamortized debt discount	(117,932)	(138,924)
Unamortized debt issuance costs	(3,647)	(5,054)	$ (5,600)
Net carrying value	740,921	718,522
2022 Notes
Debt Instrument [Line Items]
Principal outstanding	211,726	211,728
Unamortized debt discount	(21,400)	(27,569)
Unamortized debt issuance costs	(2,378)	(2,986)		$ (9,400)
Net carrying value	$ 187,948	$ 181,173

INDEBTEDNESS - Carrying Amount

INDEBTEDNESS - Carrying Amount of Equity Component of Convertible Notes (Details) - Convertible Debt - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	May 25, 2018	Mar. 06, 2017
Debt Instrument [Line Items]
Amount allocated to conversion option	$ 196,731	$ 196,731
Less: allocated issuance costs	(2,339)	(2,339)
Equity component, net	194,392	194,392
2023 Notes
Debt Instrument [Line Items]
Amount allocated to conversion option	155,250	155,250
Less: allocated issuance costs	(1,231)	(1,231)
Equity component, net	154,019	154,019	$ 155,300
2022 Notes
Debt Instrument [Line Items]
Amount allocated to conversion option	41,481	41,481
Less: allocated issuance costs	(1,108)	(1,108)
Equity component, net	$ 40,373	$ 40,373		$ 86,200

INDEBTEDNESS - Interest Expense

INDEBTEDNESS - Interest Expense on Convertible Notes (Details) - Convertible Debt - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	May 25, 2018	Mar. 06, 2017
Debt Instrument [Line Items]
Contractual interest expense	$ 1,277	$ 1,469	$ 3,831	$ 2,732
Amortization of debt discount and issuance costs	9,843	11,627	29,176	22,850
Total	$ 11,120	$ 13,096	$ 33,007	$ 25,582
2023 Notes
Debt Instrument [Line Items]
Effective interest rate of the liability component	4.69%		4.69%		4.69%
2022 Notes
Debt Instrument [Line Items]
Effective interest rate of the liability component	5.34%		5.34%			5.34%

INDEBTEDNESS - Convertible Note

INDEBTEDNESS - Convertible Note Hedge and Warrant Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	May 25, 2018	Mar. 06, 2017	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Proceeds from issuance of warrants			$ 0	$ 112,125
Convertible Debt
Debt Instrument [Line Items]
Conversion price of convertible debt (in USD per share)	$ 77.85	$ 22.95
Conversion price of convertible debt after effect of warrants and note hedge (in USD per share)	$ 109.26	$ 31.18
Common Stock Warrant
Debt Instrument [Line Items]
Warrants to purchase aggregate shares of capital stock (in shares)	11.1	19.2
Warrants, weighted average exercise price (in USD per share)	$ 109.26	$ 31.18
Proceeds from issuance of warrants	$ 112,100	$ 57,200
Shares of common stock received due to exercise of note hedges (in shares)			0.3		6.9
Options
Debt Instrument [Line Items]
Warrants to purchase aggregate shares of capital stock (in shares)	11.1	19.2
Convertible note hedge, option to purchase common stock, price (in USD per share)	$ 77.85	$ 22.95
Cost of convertible note hedge	$ 172,600	$ 92,100

ACCRUED TRANSACTION LOSSES (Det

ACCRUED TRANSACTION LOSSES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Loss Contingency Accrual
Accrued transaction losses, beginning of the period			$ 33,682
Provision for transaction losses			94,827	$ 63,603
Accrued transaction losses, end of the period	$ 37,419		37,419
Transaction Losses
Loss Contingency Accrual
Accrued transaction losses, beginning of the period	39,630	$ 29,207	33,682	26,893
Provision for transaction losses	18,225	20,449	60,223	48,794
Charge-offs to accrued transaction losses	(20,436)	(14,324)	(56,486)	(40,355)
Accrued transaction losses, end of the period	$ 37,419	$ 35,332	$ 37,419	$ 35,332

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income tax expense	$ 2,606	$ 1,066	$ 2,259	$ 1,845
Effective tax rate	8.10%	5.10%	(17.10%)	(22.00%)

STOCKHOLDERS' EQUITY - Common S

STOCKHOLDERS' EQUITY - Common Stock and Warrants Narrative (Details) $ / shares in Units, $ in Thousands	May 25, 2018USD ($)$ / sharesshares	Mar. 06, 2017USD ($)$ / sharesshares	Sep. 30, 2019USD ($)vote$ / sharesshares	Sep. 30, 2018USD ($)	Dec. 31, 2018$ / sharesshares
Class of Stock [Line Items]
Proceeds from issuance of warrants | $			$ 0	$ 112,125
Common Stock Warrant
Class of Stock [Line Items]
Warrants to purchase aggregate shares of capital stock (in shares)	11,100,000	19,200,000
Warrants, weighted average exercise price (in USD per share) | $ / shares	$ 109.26	$ 31.18
Proceeds from issuance of warrants | $	$ 112,100	$ 57,200
Number of warrants exercised (in shares)			0
Class A
Class of Stock [Line Items]
Common stock, number of votes entitled for each share held (in votes) | vote			1
Common stock, shares authorized (in shares)			1,000,000,000		1,000,000,000
Common stock, par value (in USD per share) | $ / shares			$ 0.00		$ 0.00
Common stock, shares outstanding (in shares)			346,552,092		323,546,864
Class B
Class of Stock [Line Items]
Common stock, number of votes entitled for each share held (in votes) | vote			10
Common stock, shares authorized (in shares)			500,000,000		500,000,000
Common stock, par value (in USD per share) | $ / shares			$ 0.00		$ 0.00
Common stock, shares outstanding (in shares)			82,521,716		93,501,142

STOCKHOLDERS' EQUITY - Stock Pl

STOCKHOLDERS' EQUITY - Stock Plans and Share Based Compensation Narrative (Details) $ in Thousands	Nov. 17, 2015shares	Sep. 30, 2019USD ($)shares	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)planshares	Sep. 30, 2018USD ($)
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 | $		$ 77,426	$ 58,913	$ 217,980	$ 157,856
Capitalized share-based compensation expense | $		2,400	2,000	6,000	6,300
Unrecognized compensation cost, options | $		745,000		745,000
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, compensation expense | $		$ 5,100	$ 2,000	$ 14,100	$ 6,300
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, period for recognition				2 years 9 months 18 days
2009 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)		0		0
2009 Stock Option Plan | Stock options, RSAs, and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments outstanding (in shares)		20,422,313		20,422,313
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)		82,968,841		82,968,841
Shares reserved for future issuance (in shares)	30,000,000
Shares reserved for future issuance, percentage of annual increase	5.00%
2015 Equity Incentive Plan | Stock options, RSAs, and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments outstanding (in shares)		21,822,262		21,822,262
2015 Equity Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance, amount of annual increase (in shares)	40,000,000

STOCKHOLDERS' EQUITY - Stock Op

STOCKHOLDERS' EQUITY - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Number of Stock Options Outstanding
Beginning balance (in shares)		33,152,881
Granted (in shares)		1,184,657
Exercised (in shares)		(7,881,289)
Forfeited (in shares)		(136,772)
Ending balance (in shares)	26,319,477	26,319,477	33,152,881
Weighted Average Exercise Price
Beginning balance (in USD per share)		$ 9.52
Granted (in USD per share)		72.15
Exercised (in USD per share)		7.97
Forfeited (in USD per share)		11.70
Ending balance (in USD per share)	$ 12.80	$ 9.52	$ 9.52
Options Exercisable
Options exercisable (in shares)	24,136,540
Options exercisable (in USD per share)	$ 9.40
Additional Disclosures
Weighted average remaining contractual term, options outstanding		5 years 2 months 23 days	5 years 5 months 12 days
Weighted average remaining contractual term, options exercisable		4 years 11 months 1 day
Aggregate intrinsic value, options outstanding	$ 1,305,789		$ 1,543,793
Aggregate intrinsic value, options exercisable	$ 1,269,509

STOCKHOLDERS' EQUITY - Restrict

STOCKHOLDERS' EQUITY - Restricted Stock Awards and Restricted Stock Units Activity (Details) - RSAs and RSUs	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Number of shares
Beginning balance (in shares) | shares	17,934,728
Granted (in shares) | shares	5,735,224
Vested (in shares) | shares	(6,016,950)
Forfeited (in shares) | shares	(1,727,904)
Ending balance (in shares) | shares	15,925,098
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share) | $ / shares	$ 31.34
Granted (in USD per share) | $ / shares	73.29
Vested (in USD per share) | $ / shares	29.05
Forfeited (in USD per share) | $ / shares	35.90
Ending balance (in USD per share) | $ / shares	$ 46.82

STOCKHOLDERS' EQUITY - Stock _2

STOCKHOLDERS' EQUITY - Stock Option Fair Value Assumptions (Details) - Stock options	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
Risk-free interest rate	2.48%	2.92%
Expected volatility	39.52%	30.87%
Expected term (years)	6 years 18 days	6 years 2 months 8 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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 77,426	$ 58,913	$ 217,980	$ 157,856
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	38	18	88	79
Product development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	56,321	39,525	155,114	103,813
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	6,269	6,108	20,304	16,703
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 14,798	$ 13,262	$ 42,474	$ 37,261

NET INCOME (LOSS) PER SHARE - C

NET INCOME (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, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income (loss)	$ 29,397	$ (6,740)	$ (38,151)	$ 19,643	$ (5,906)	$ (23,986)	$ (15,494)	$ (10,249)
Basic shares:
Weighted-average common shares outstanding (in shares)	427,906			410,095			423,957	403,577
Weighted-average unvested shares (in shares)	(782)			(405)			(718)	(597)
Weighted-average shares used to compute basic net loss per share (in shares)	427,124			409,690			423,239	402,980
Diluted shares:
Stock options and restricted stock units	28,549			47,175			0	0
Convertible senior notes	0			6,409			0	0
Common stock warrants	10,372			11,422			0	0
Employee stock purchase plan	54			219			0	0
Weighted-average shares used to compute diluted income (loss) per share (in shares)	466,099			474,915			423,239	402,980
Net income (loss) per share:
Basic (in USD per share)	$ 0.07			$ 0.05			$ (0.04)	$ (0.03)
Diluted (in USD per share)	$ 0.06			$ 0.04			$ (0.04)	$ (0.03)

NET INCOME (LOSS) PER SHARE - A

NET INCOME (LOSS) PER SHARE - Antidilutive Securities Excluded from Computation of Diluted Net Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net income (loss) per share (in shares)	56,269	54,755	97,537	112,289
Stock options and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net income (loss) per share (in shares)	15,113	12,079	46,045	62,822
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net income (loss) per share (in shares)	19,880	18,830	30,252	24,387
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net income (loss) per share (in shares)	20,305	23,415	20,305	24,276
Unvested shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net income (loss) per share (in shares)	782	405	718	597
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net income (loss) per share (in shares)	189	26	217	207

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jul. 31, 2019
Related Party Transaction [Line Items]
Lease executed but not yet commenced, term		15 years 6 months
Lease executed but not yet commenced	$ 344,202	$ 42,700
Affiliated Entity
Related Party Transaction [Line Items]
Lease executed but not yet commenced, term		15 years 6 months
Lease executed but not yet commenced		$ 42,700

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Operating and Finance Leases Narrative (Details) $ in Thousands	1 Months Ended		9 Months Ended
	Jul. 31, 2019USD ($)ft²renewal_option	Dec. 31, 2018USD ($)ft²renewal_option	Sep. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease renewal term			5 years
Operating lease option to terminate term			1 year
Total lease payments over term			$ 492,508
Leased area of office space executed but not yet commenced (in sq ft) | ft²	226,258
Lease executed but not yet commenced, term	15 years 6 months
Lease executed but not yet commenced, number of renewal options | renewal_option	2
Lease executed but not yet commenced renewal term	5 years
Lease executed but not yet commenced	$ 42,700		$ 344,202
Minimum
Lessee, Lease, Description [Line Items]
Operating lease term			1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease term			12 years
Lease executed but not yet commenced, option to terminate leased space (up to)	50.00%
Equipment
Lessee, Lease, Description [Line Items]
Finance lease, remaining lease term			2 years
Oakland, California | Building
Lessee, Lease, Description [Line Items]
Operating lease term		12 years
Operating lease renewal term		5 years
Leased area of office space (in sq ft) | ft²		355,762
Operating lease, number of renewal options | renewal_option		2
Total lease payments over term		$ 276,000

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Schedule of Lease Expense Components (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Fixed operating lease costs	$ 7,449	$ 21,626
Variable operating lease costs	1,646	3,871
Sublease income	(1,468)	(1,570)
Finance lease costs
Amortization of finance right-of-use assets	1,284	3,861
Interest on finance lease liabilities	0	0
Total lease costs	$ 8,911	$ 27,788

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Other Information Related to Leases (Details)	Sep. 30, 2019
Weighted Average Remaining Lease Term:
Operating leases	4 years 6 months
Finance leases	27 days
Weighted Average Discount Rate:
Operating leases	4.00%
Finance leases	0.00%

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES - Cash Flows Related to Leases (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Cash flows from operating activities:
Payments for operating lease liabilities	$ 24,580
Cash flows from financing activities:
Principal payments on finance lease obligation	3,860
Supplemental Cash Flow Data:
Right-of-use assets obtained in exchange for operating lease obligations	$ 31,013

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES - Schedule of Future Minimum Lease Payments Under Non-Cancelable Operating Leases and Finance Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jul. 31, 2019
Finance
2019 (remaining 3 months)	$ 1,178
2020	2,446
2021	0
2022	0
2023	0
Thereafter	0
Total	3,624
Less: amount representing interest	0
Less: leases executed but not yet commenced	0
Total	3,624
Operating
2019 (remaining 3 months)	5,942
2020	40,388
2021	59,459
2022	61,005
2023	54,842
Thereafter	270,872
Total	492,508
Less: amount representing interest	13,245
Less: leases executed but not yet commenced	344,202	$ 42,700
Lessee, Finance Lease, Lease Incentive Payable And Transfer To Held-For-Sale	0
Less: lease incentives and transfer to held for sale	2,825
Total	$ 132,236

COMMITMENTS AND CONTINGENCIES_6

COMMITMENTS AND CONTINGENCIES - Litigation (Details) - USD ($)	Sep. 06, 2019	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Gross receipts tax and payroll expense tax paid		$ 1,300,000
Minimum
Income Tax Examination [Line Items]
Estimate of possible liability for additional taxes, interest and penalties	$ 0
Maximum
Income Tax Examination [Line Items]
Estimate of possible liability for additional taxes, interest and penalties	$ 56,000,000

SEGMENT AND GEOGRAPHICAL INFO_3

SEGMENT AND GEOGRAPHICAL INFORMATION - Narrative (Details)	9 Months Ended
	Sep. 30, 2019segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

SEGMENT AND GEOGRAPHICAL INFO_4

SEGMENT AND GEOGRAPHICAL INFORMATION - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,266,474	$ 882,108	$ 3,400,071	$ 2,365,649
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,200,488	838,149	3,233,432	2,255,657
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 65,986	$ 43,959	$ 166,639	$ 109,992

SEGMENT AND GEOGRAPHICAL INFO_5

SEGMENT AND GEOGRAPHICAL INFORMATION - Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 581,471	$ 481,209
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	570,273	471,970
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 11,198	$ 9,239

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Supplemental Cash Flow Data:
Cash paid for interest	$ 3,377	$ 1,945
Cash paid for income taxes	2,266	1,265
Right-of-use assets obtained in exchange for operating lease obligations	31,013
Supplemental disclosures of non-cash investing and financing activities:
Change in purchases of property and equipment in accounts payable and accrued expenses	11,402	11,004
Unpaid business combination purchase price	8,411	3,995
Fair value of common stock issued related to business combination	0	(140,107)
Recovery of common stock in connection with indemnification settlement agreement	789	2,745
Fair value of common stock issued to settle the conversion of senior notes, due 2022	0	(189,916)
Fair value of shares received to settle senior note hedges, due 2022	$ 0	$ 189,916

Uncategorized Items - q3fy19squ

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (4,586,000)
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (4,586,000)