Wayfair (W) 10-Q 5 Aug 21 2021 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2021	Jul. 29, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-36666
Entity Registrant Name	Wayfair Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-4791999
Entity Address, Address Line One	4 Copley Place
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02116
City Area Code	617
Local Phone Number	532-6100
Title of each class	Class A Common Stock, $0.001 par value per share
Trading symbol(s)	W
Name of each exchange on which registered	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
Entity Central Index Key	0001616707
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		77,336,571
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		26,563,761

CONSOLIDATED AND CONDENSED BALA

CONSOLIDATED AND CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 2,078,451	$ 2,129,440
Short-term investments	523,390	461,698
Accounts receivable, net	129,410	110,299
Inventories	59,914	52,152
Prepaid expenses and other current assets	342,695	292,213
Total current assets	3,133,860	3,045,802
Operating lease right-of-use assets	842,670	808,375
Property and equipment, net	663,987	684,306
Other non-current assets	40,707	31,446
Total assets	4,681,224	4,569,929
Current liabilities
Accounts payable	1,262,395	1,156,624
Other current liabilities	963,235	1,008,970
Total current liabilities	2,225,630	2,165,594
Long-term debt	3,047,983	2,659,243
Operating lease liabilities	899,431	869,958
Other non-current liabilities	50,058	67,031
Total liabilities	6,223,102	5,761,826
Commitments and Contingencies
Stockholders’ deficit:
Convertible preferred stock, $0.001 par value per share: 10,000,000 shares authorized and none issued at June 30, 2021 and December 31, 2020	0	0
Additional paid-in capital	131,706	698,482
Accumulated deficit	(1,669,009)	(1,885,950)
Accumulated other comprehensive loss	(4,679)	(4,529)
Total stockholders’ deficit	(1,541,878)	(1,191,897)
Total liabilities and stockholders’ deficit	4,681,224	4,569,929
Class A common stock
Stockholders’ deficit:
Common stock	77	73
Class B common stock
Stockholders’ deficit:
Common stock	$ 27	$ 27

CONSOLIDATED AND CONDENSED BA_2

CONSOLIDATED AND CONDENSED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Convertible redeemable preferred units, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible redeemable preferred units, shares authorized (in shares)	10,000,000	10,000,000
Convertible redeemable preferred units, shares issued (in shares)	0	0
Class A common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	77,013,108	72,980,490
Common stock, shares outstanding (in shares)	77,013,108	72,980,490
Class B common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	164,000,000	164,000,000
Common stock, shares issued (in shares)	26,563,837	26,564,234
Common stock, shares outstanding (in shares)	26,563,837	26,564,234

CONSOLIDATED AND CONDENSED STAT

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net revenue	$ 3,857,626	$ 4,304,672	$ 7,335,144	$ 6,634,735
Cost of goods sold	2,729,566	2,983,642	5,204,057	4,734,582
Gross profit	1,128,060	1,321,030	2,131,087	1,900,153
Operating expenses:
Customer service and merchant fees	144,630	143,773	291,871	233,236
Advertising	351,775	417,777	717,638	693,537
Selling, operations, technology, general and administrative	486,448	459,482	937,817	935,450
Customer service center impairment and other charges	0	0	12,212	0
Total operating expenses	982,853	1,021,032	1,959,538	1,862,223
Income from operations	145,207	299,998	171,549	37,930
Interest expense, net	(8,402)	(28,939)	(15,214)	(51,157)
Other (expense) income, net	(2,248)	3,110	(5,546)	2,864
Income (loss) before income taxes	134,557	274,169	150,789	(10,363)
Provision for income taxes, net	4,129	292	2,127	1,625
Net income (loss)	$ 130,428	$ 273,877	$ 148,662	$ (11,988)
Earnings (loss) per share:
Basic (in usd per share)	$ 1.26	$ 2.89	$ 1.44	$ (0.13)
Diluted (in usd per share)	$ 1.14	$ 2.54	$ 1.33	$ (0.13)
Weighted-average number of shares of common stock outstanding used in computing per share amounts:
Basic (in shares)	103,829	94,834	103,337	94,461
Diluted (in shares)	122,092	119,932	118,640	94,461

CONSOLIDATED AND CONDENSED ST_2

CONSOLIDATED AND CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 130,428	$ 273,877	$ 148,662	$ (11,988)
Other comprehensive income (loss):
Foreign currency translation adjustments	(2,740)	(1,093)	(97)	230
Net unrealized (loss) gain on available-for-sale investments	(50)	(73)	(53)	673
Comprehensive income (loss)	$ 127,638	$ 272,711	$ 148,512	$ (11,085)

CONSOLIDATED AND CONDENSED ST_3

CONSOLIDATED AND CONDENSED STATEMENTS OF STOCKHOLDERS' DEFICIT - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Class A and Class B Common Stock	Additional Paid-In Capital	Additional Paid-In CapitalCumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive (Loss)
Balance (in shares) at Dec. 31, 2019			93,600
Balance at Dec. 31, 2019	$ (944,208)	$ (5,523)	$ 94	$ 1,122,548		$ (2,065,423)	$ (5,523)	$ (1,427)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(11,988)					(11,988)
Other comprehensive loss	903							903
Exercise of options to purchase common stock (in shares)			18
Exercise of options to purchase common stock	220			220
Issuance of common stock upon vesting of RSUs (in shares)			1,447
Issuance of common stock upon vesting of RSUs	1		$ 1
Equity-based compensation expense	134,314			134,314
Shares issued upon conversion of convertible notes (Note 4)	38,889			38,889
Balance (in shares) at Jun. 30, 2020			95,065
Balance at Jun. 30, 2020	(787,392)		$ 95	1,295,971		(2,082,934)		(524)
Balance (in shares) at Dec. 31, 2019			93,600
Balance at Dec. 31, 2019	(944,208)	(5,523)	$ 94	1,122,548		(2,065,423)	(5,523)	(1,427)
Balance (in shares) at Dec. 31, 2020			99,545
Balance at Dec. 31, 2020	$ (1,191,897)	(630,203)	$ 100	698,482	$ (698,482)	(1,885,950)	68,279	(4,529)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	Adoption of ASU 2020-06
Balance (in shares) at Mar. 31, 2020			94,363
Balance at Mar. 31, 2020	$ (1,171,401)		$ 94	1,184,674		(2,356,811)		642
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	273,877					273,877
Other comprehensive loss	(1,166)							(1,166)
Exercise of options to purchase common stock (in shares)			11
Exercise of options to purchase common stock	95			95
Issuance of common stock upon vesting of RSUs (in shares)			691
Issuance of common stock upon vesting of RSUs	1		$ 1
Equity-based compensation expense	72,313			72,313
Shares issued upon conversion of convertible notes (Note 4)	38,889			38,889
Balance (in shares) at Jun. 30, 2020			95,065
Balance at Jun. 30, 2020	(787,392)		$ 95	1,295,971		(2,082,934)		(524)
Balance (in shares) at Dec. 31, 2020			99,545
Balance at Dec. 31, 2020	(1,191,897)	$ (630,203)	$ 100	698,482	$ (698,482)	(1,885,950)	$ 68,279	(4,529)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	148,662					148,662
Other comprehensive loss	(150)							(150)
Exercise of options to purchase common stock (in shares)			19
Exercise of options to purchase common stock	56			56
Issuance of common stock upon vesting of RSUs (in shares)			1,362
Issuance of common stock upon vesting of RSUs	1		$ 1
Equity-based compensation expense	167,033			167,033
Repurchase of common stock (in shares)			(983)
Repurchase of common stock	(300,208)		$ (1)	(300,207)
Shares issued upon conversion of convertible notes (Note 4) (in shares)			3,634
Shares issued upon conversion of convertible notes (Note 4)	264,828		$ 4	264,824
Balance (in shares) at Jun. 30, 2021			103,577
Balance at Jun. 30, 2021	(1,541,878)		$ 104	131,706		(1,669,009)		(4,679)
Balance (in shares) at Mar. 31, 2021			103,760
Balance at Mar. 31, 2021	(1,469,709)		$ 104	331,513		(1,799,437)		(1,889)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	130,428
Other comprehensive loss	(2,790)							(2,790)
Exercise of options to purchase common stock (in shares)			7
Exercise of options to purchase common stock	11			11
Issuance of common stock upon vesting of RSUs (in shares)			653
Issuance of common stock upon vesting of RSUs	1		$ 1
Equity-based compensation expense	85,805			85,805
Repurchase of common stock (in shares)			(982)
Repurchase of common stock	(300,020)		$ (1)	(300,019)
Shares issued upon conversion of convertible notes (Note 4) (in shares)			139
Shares issued upon conversion of convertible notes (Note 4)	14,396			14,396
Balance (in shares) at Jun. 30, 2021			103,577
Balance at Jun. 30, 2021	$ (1,541,878)		$ 104	$ 131,706		$ (1,669,009)		$ (4,679)

CONSOLIDATED AND CONDENSED ST_4

CONSOLIDATED AND CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ 148,662	$ (11,988)
Adjustments used to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	158,237	135,957
Equity-based compensation	153,883	127,081
Amortization of discount and issuance costs on convertible notes	3,969	46,488
Loss on impairment	12,212	0
Other non-cash adjustments	498	(531)
Changes in operating assets and liabilities:
Accounts receivable, net	(19,659)	(24,693)
Inventories	(7,458)	18,828
Prepaid expenses and other current assets	(51,782)	(114,296)
Other assets	(4,010)	938
Accounts payable and other current liabilities	56,707	677,536
Other liabilities	776	23,641
Cash flows from operating activities	452,035	878,961
Cash flows from investing activities:
Purchase of short- and long-term investments	(612,627)	0
Sale and maturities of short- and long-term investments	550,131	368,310
Purchase of property and equipment	(49,072)	(104,810)
Site and software development costs	(84,836)	(75,172)
Other investing activities, net	0	(124)
Net cash (for) from investing activities	(196,404)	188,204
Cash flows from financing activities:
Repurchase of common stock	(300,208)	0
Proceeds from borrowings	0	200,000
Repayment of borrowings	0	(200,000)
Proceeds from issuance of convertible notes, net of issuance costs	0	527,423
Other financing activities, net	56	220
Net cash (for) from financing activities	(300,152)	527,643
Effect of exchange rate changes on cash and cash equivalents	(6,468)	3,910
Net (decrease) increase in cash and cash equivalents	(50,989)	1,598,718
Cash and cash equivalents:
Beginning of period	2,129,440	582,753
End of period	2,078,451	2,181,471
Supplemental cash flow information:
Cash paid for interest on long-term debt	13,994	8,681
Issuance of common stock for conversion of convertible debt	264,824	0
Purchase of property and equipment included in accounts payable and accrued expenses and in other liabilities	$ 26,697	$ 34,040

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited consolidated and condensed financial statements contained in this Quarterly Report on Form 10-Q are those of Wayfair Inc. and its wholly-owned subsidiaries. Unless the context indicates otherwise, references to “we,” “us” and “our” refer to Wayfair Inc. and its subsidiaries. In our opinion, the accompanying unaudited consolidated and condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States ("GAAP") and applicable rules and regulations of the U.S. Securities and Exchange Commission ("SEC") regarding interim financial reporting and reflect all adjustments, consisting of normal recurring adjustments, necessary to present fairly the results of the interim periods presented. Certain information and note disclosures normally included in the audited financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2020. Furthermore, interim results are not necessarily indicative of the results for the full year ended December 31, 2021 or future periods. Wayfair believes that other than the adoption of new accounting pronouncements that follow, there have been no significant changes during the three and six months ended June 30, 2021 to the items disclosed in Note 1, Summary of Significant Accounting Policies , included in Part II, Item 8, Financial Statements and Supplementary Data , of our Annual Report on Form 10-K for the year ended December 31, 2020. Adoption of New Accounting Pronouncements Convertible Debt Wayfair adopted ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity (Subtopic 815-40) ("ASU 2020-06") on January 1, 2021 using the modified retrospective approach for all financial instruments that are outstanding as of the adoption date. The new standard eliminates the cash conversion and beneficial conversion feature models that previously required separate accounting for conversion features. Entities that had those conversion features will report less interest expense as those conversion features were recorded as debt discounts which were amortized over the term of the debt. In addition, this ASU requires the application of the if-converted method when calculating diluted earnings per share. Under the new standard, the conversion of debt that is accounted for as a liability in its entirety will not result in any gain or loss if the conversion feature is exercised according to the original conversion terms. If those terms allowed the issuer to include cash as part of the settlement of the conversion feature, the issuer will first reduce the carrying amount of the convertible debt, including any unamortized premium, discount or issuance costs, by the value of the cash or other assets transferred and then recognize the remaining carrying value of the debt in the capital accounts. The adoption of ASU 2020-06 resulted in the following adjustments to the consolidated and condensed balance sheets: January 1, 2021 Adoption of ASU 2020-06 December 31, 2020 (in thousands) Balance sheet line item: Long-term debt $ 3,310,065 $ 650,822 $ 2,659,243 Other non-current liabilities $ 46,413 $ (20,618) $ 67,031 Additional paid-in capital $ — $ (698,482) $ 698,482 Accumulated deficit $ (1,817,671) $ 68,279 $ (1,885,950) The adoption of ASU 2020-06 resulted in the following adjustments to our calculations of basic and diluted earnings per share for the three months ended June 30, 2021: Under ASU 2020-06 Difference Under Legacy Accounting Earnings (loss) per share: Basic $ 1.26 $ 0.28 $ 0.98 Diluted $ 1.14 $ 0.19 $ 0.95 The adoption of ASU 2020-06 resulted in the following adjustments to our calculations of basic and diluted earnings per share for the six months ended June 30, 2021: Under ASU 2020-06 Difference Under Legacy Accounting Earnings (loss) per share: Basic $ 1.44 $ 0.76 $ 0.68 Diluted $ 1.33 $ 0.67 $ 0.66 The adoption of ASU 2020-06 did not materially impact our cash flows or compliance with debt covenants. Income Taxes Wayfair adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ ASU 2019-12”) on January 1, 2021, using the modified retrospective approach. This ASU simplifies the accounting for income taxes, removes certain exceptions to the general principles in Topic 740, and clarifies and amends existing guidance to improve consistent application. The effect of adoption of the new guidance was not material to our consolidated financial statements. Investments Wayfair classifies investments in certificates of deposits and marketable securities with original maturities of greater than three months as short-term investments and long-term investments on our consolidated balance sheets. Short-term investments mature in less than twelve months from the balance sheet date. We determine the cost basis of an investment sold using the specific identification method. To the extent the amortized cost basis of the available-for-sale debt securities exceeds the fair value, management assesses the debt securities for credit loss. However, management considers the risk of credit loss to be minimized by Wayfair’s policy of investing in financial instruments issued by highly-rated financial institutions. When assessing the risk of credit loss, management considers factors such as the severity and the reason of the decline in value (i.e., any changes to the rating of the security by a rating agency or other adverse conditions specifically related to the security) and management’s intended holding period and time horizon for selling. From time to time, Wayfair may enter into equity investments that align with our organizational strategies and growth initiatives. Equity investments in companies for which we do not have the ability to exercise significant influence are accounted for at estimated fair value, with adjustments for observable changes in prices or impairments, and are classified as other non-current assets on our consolidated and condensed balance sheets with adjustments recognized in other (expense) income, net on our consolidated and condensed statements of operations. Each reporting period, we perform a qualitative assessment to evaluate whether each investment is impaired. Our assessment includes a review of recent operating results and trends, recent sales or acquisitions of the investee securities and other readily observable information. If the investment is impaired, we write it down to its estimated fair value. Equity investments are accounted for using the equity method of accounting if the investment gives us the ability to exercise significant influence, but not control, over an investee, and we classify equity-method investments as other non-current assets on our consolidated and condensed balance sheets. Our share of the earnings or losses as reported by equity-method investees, amortization of basis differences, related gains or losses, and impairments, if any, are recognized in our consolidated and condensed statements of operations. Each reporting period, we evaluate whether declines in fair value below carrying value are other-than-temporary and if so, we write down the investment to its estimated fair value.

Supplemental Financial Statemen

Supplemental Financial Statement Disclosures	6 Months Ended
	Jun. 30, 2021
Supplemental Financial Statement Disclosures [Abstract]
Supplemental Financial Statement Disclosures	2. Supplemental Financial Statement Disclosures Accounts Receivable, Net As of June 30, 2021, we reported accounts receivable of $129.4 million, net of allowance for credit losses of $18.7 million. As of December 31, 2020, we reported accounts receivable of $110.3 million, net of allowance for credit losses of $21.4 million. The changes in the allowance for credit losses were not material for the three and six months ended June 30, 2021. Management believes credit risk is mitigated since approximately 99% of the net revenue recognized for the three and six months ended June 30, 2021 was collected in advance of recognition. Contractual Liabilities Contractual liabilities included in other current liabilities was $317.0 million at June 30, 2021 and $298.1 million at December 31, 2020. During the six months ended June 30, 2021, Wayfair recognized $234.1 million of net revenue that was included in other current liabilities as of December 31, 2020. Net revenue from contracts with customers is disaggregated by geographic region because this manner of disaggregation best depicts how the nature, amount, timing, and uncertainty of net revenue and cash flows are affected by economic factors. Refer to Note 10, Segment and Geographic Information , for additional detail. Customer Service Center Impairment and Other Charges

Cash and Cash Equivalents, Inve

Cash and Cash Equivalents, Investments, and Fair Value Measurements	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Cash and Cash Equivalents, Investments, and Fair Value Measurements	3. Cash and Cash Equivalents, Investments and Fair Value Measurements Investments As of June 30, 2021 and December 31, 2020, all of Wayfair’s marketable securities, which primarily consisted of corporate bonds and other government obligations that are priced at fair value, were classified as available-for-sale investments. Wayfair did not have any realized gains nor losses during the three and six months ended June 30, 2021 or during the three months ended June 30, 2020. During the six months ended June 30, 2020, Wayfair collected $161.3 million of proceeds from the sale of long-term investments and recognized a realized gain of $0.8 million. During the three and six months ended June 30, 2021 and June 30, 2020, Wayfair did not recognize any credit losses related to its available-for-sale debt securities. Further, as of June 30, 2021 and December 31, 2020, Wayfair did not record an allowance for credit losses related to its available-for-sale debt securities. In the second quarter of 2021, Wayfair entered into an agreement with a vendor in which Wayfair received warrants to acquire shares of the vendor’s common stock, which, subsequent to June 30, 2021, the vendor offered through an initial public offering. These warrants, which vest over a five-year period, were estimated to have a value of approximately $5.8 million and are classified in other non-current assets. We did not record any changes in value of the warrants during the three and six months ended June 30, 2021. Furthermore, we committed to make $20.0 million of other equity investments in connection with our impact investment initiatives, which will be accounted for under the equity method. Subsequent to June 30, 2021, Wayfair made a $5.0 million initial investment in the partnership. The following tables present details of Wayfair’s investment securities as of June 30, 2021 and December 31, 2020: June 30, 2021 Amortized Gross Gross Estimated (in thousands) Short-term: Investment securities $ 523,428 $ 4 $ (42) $ 523,390 December 31, 2020 Amortized Gross Unrealized Gains Gross Estimated (in thousands) Short-term: Investment securities $ 461,683 $ 20 $ (5) $ 461,698 Fair Value Measurements Wayfair's financial assets and liabilities are measured at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The three levels of inputs used to measure fair value are as follows: ▪ Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities ▪ Level 2—Unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable or can be corroborated by observable market data for substantially the full-term of the asset or liability ▪ Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the asset or liability This hierarchy requires Wayfair to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. We classify our cash equivalents and certificate of deposits within Level 1 because we value these investments using quoted market prices. The fair value of our Level 1 financial assets is based on quoted market prices of the identical underlying security. We classify short-term investments within Level 2 because unadjusted quoted prices for identical or similar assets in markets are not active. None of our cash and cash equivalents or investments are classified as Level 3. The following tables set forth the fair value of Wayfair’s financial assets measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020: June 30, 2021 Level 1 Level 2 Level 3 Total (in thousands) Cash and cash equivalents: Cash $ 437,502 $ — $ — $ 437,502 Cash equivalents 1,640,949 — — 1,640,949 Total cash and cash equivalents 2,078,451 — — 2,078,451 Short-term investments: Investment securities — 523,390 — 523,390 Other non-current assets: Certificate of deposit 5,200 — — 5,200 Total $ 2,083,651 $ 523,390 $ — $ 2,607,041 December 31, 2020 Level 1 Level 2 Level 3 Total (in thousands) Cash and cash equivalents: Cash $ 638,621 $ — $ — $ 638,621 Cash equivalents 1,490,819 — — 1,490,819 Total cash and cash equivalents 2,129,440 — — 2,129,440 Short-term investments: Investment securities — 461,698 — 461,698 Other non-current assets: Certificate of deposit 5,200 — — 5,200 Total $ 2,134,640 $ 461,698 $ — $ 2,596,338

Debt and Other Financing

Debt and Other Financing	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt and Other Financing	4. Debt and Other Financing The following table presents the outstanding principal amount and carrying value of debt and other financing as of the dates presented: June 30, 2021 December 31, 2020 Debt Instrument Principal Amount Unamortized Debt Discount Net Carrying Amount Principal Amount Unamortized Debt Discount Net Carrying Amount (in thousands) 2022 Notes $ 3,113 $ (14) $ 3,099 $ 18,036 $ (1,596) $ 16,440 2024 Notes 575,000 (7,404) 567,596 575,000 (132,892) 442,108 2026 Notes 948,745 (10,090) 938,655 948,750 (242,911) 705,839 2025 Notes 1,518,000 (14,849) 1,503,151 1,518,000 (289,954) 1,228,046 2025 Accreting Notes 35,868 (386) 35,482 288,464 (21,654) 266,810 Total Debt $ 3,047,983 $ 2,659,243 Short-term debt $ — $ — Long-term debt $ 3,047,983 $ 2,659,243 Revolving Credit Facility On March 24, 2021, Wayfair and certain of its subsidiaries (together, the “Guarantors”) and Wayfair LLC, a wholly-owned subsidiary of Wayfair, as borrower (the “Borrower”), entered into a new credit agreement (the “Credit Agreement”) with the lending institutions from time to time parties thereto and Citibank, N.A., in its capacity as administrative agent, collateral agent, swingline lender and a letter of credit issuer. The Credit Agreement provides for a $600 million senior secured revolving credit facility that matures on March 24, 2026 (the “Revolver”). The Revolver replaced our previous $200 million senior secured revolving credit facility (the “Previous Revolver”), which was set to mature on February 21, 2022. Wayfair paid all amounts owed under the Previous Revolver and terminated all lending commitments thereunder. Debt issuance costs for the Revolver are included in other non-current assets and are amortized to interest expense over the Revolver’s term. Under the Credit Agreement, the Borrower may from time to time request letters of credit, which reduce the availability of credit under the Revolver. Wayfair had approximately $60.2 million outstanding letters of credit as of June 30, 2021, primarily as security for lease agreements, which reduced the availability of credit under the Revolver. Any amounts outstanding under the Revolver are due at maturity. In addition, subject to the terms and conditions set forth in the Credit Agreement, the Borrower is required to make certain mandatory prepayments prior to maturity. The proceeds of the Revolver may be used to finance working capital, to refinance existing indebtedness and to provide funds for permitted acquisitions, repurchases of equity interests and other general corporate purposes. The Borrower’s obligations under the Revolver are guaranteed by the Guarantors. The obligations of the Borrower and the Guarantors are secured by first-priority liens on substantially all of the assets of the Borrower and the Guarantors, including, with certain exceptions, all of the capital stock of Wayfair’s domestic subsidiaries and 65% of the capital stock of Wayfair’s first-tier foreign subsidiaries. Revolver borrowings bear interest through maturity at a variable rate based upon, at the Borrower’s option, either the LIBOR rate or the base rate (which is the highest of (x) the prime rate, (y) one-half of 1.00% in excess of the federal funds effective rate and (z) 1.00% in excess of the one-month LIBOR rate), plus, in each case an applicable margin. As of June 30, 2021, the applicable margin for LIBOR loans is 1.25% per annum and the applicable margin for base rate loans is 0.25% per annum. The applicable margin is subject to specified changes depending on Wayfair’s Consolidated Senior Secured Debt to Consolidated EBITDA Ratio, as defined in the Credit Agreement. The Credit Agreement contains affirmative and negative covenants customarily applicable to senior secured credit facilities, including covenants that, among other things, limit or restrict the ability of the Borrower and the Guarantors, subject to negotiated exceptions, to incur additional indebtedness and additional liens on their assets, engage in mergers or acquisitions or dispose of assets, pay dividends or make other distributions, voluntarily prepay other indebtedness, enter into transactions with affiliated persons, make investments, or change the nature of their businesses. The Revolver also contains customary events of default, subject to thresholds and grace periods, including, among others, payment default, covenant default, cross default to other material indebtedness and judgment default. In addition, the Credit Agreement requires Wayfair to maintain a Consolidated Senior Secured Debt to Consolidated EBITDA Ratio (as defined in the Credit Agreement) of 4.0 to 1.0, subject to a 0.5 step-up following certain permitted acquisitions. We do not expect any of these restrictions to affect or limit our ability to conduct business in the ordinary course. As of June 30, 2021, we were in compliance with all covenants. Convertible Non-Accreting Notes The following table summarizes certain terms related to our outstanding convertible notes, excluding the 2025 Accreting Notes: Convertible Non-Accreting Notes Maturity Date Annual Coupon Rate Annual Effective Interest Rate Payment Dates for Semi-Annual Interest Payments in Arrears 2022 Notes September 1, 2022 0.375% 0.9% March 1 and September 1 2024 Notes November 1, 2024 1.125% 1.5% May 1 and November 1 2026 Notes August 15, 2026 1.000% 1.2% February 15 and August 15 2025 Notes October 1, 2025 0.625% 0.9% April 1 and October 1 Convertible Accreting Notes No cash interest is payable on the 2025 Accreting Notes. Instead, the 2025 Accreting Notes accrue interest at a rate of 2.50% per annum, which accretes to the principal amount on April 1 and October 1 of each year. The 2025 Accreting Notes will mature on April 1, 2025, unless earlier purchased, redeemed or converted. The annual effective interest rate of the 2025 Accreting Notes is 2.7%. Conversion and Redemption Terms of the Notes Wayfair's Notes will mature at their maturity date unless earlier purchased, redeemed or converted. The Notes’ initial conversion terms are summarized below: Convertible Notes Maturity Date Free Convertibility Date Initial Conversion Rate per $1,000 Principal Initial Conversion Price Redemption Date 2022 Notes September 1, 2022 June 1, 2022 9.6100 $104.06 September 8, 2020 2024 Notes November 1, 2024 August 1, 2024 8.5910 $116.40 May 8, 2022 2026 Notes August 15, 2026 May 15, 2026 6.7349 $148.48 August 20, 2023 2025 Notes October 1, 2025 July 1, 2025 2.3972 $417.15 October 4, 2022 2025 Accreting Notes April 1, 2025 - 13.7931 $72.50 May 9, 2023 The conversion rate is subject to adjustment upon the occurrence of certain specified events, including certain distributions and dividends to all or substantially all of the holders of Wayfair’s Class A common stock, but will not be adjusted for accrued and unpaid interest. Wayfair will settle any conversions of the Non-Accreting Notes in cash, shares of Wayfair’s Class A common stock or a combination thereof, with the form of consideration determined at Wayfair’s election. The holders of the Non-Accreting Notes may convert all or a portion of the notes prior to certain conversion dates (the “Free Convertibility Date”) under the following circumstances (in each case, as applicable to each series of Non-Accreting Notes): • during any calendar quarter (and only during such calendar quarter) after June 30, 2021, if the last reported sale price of Wayfair’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, and including, 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; • during the five ten • if Wayfair calls the notes for redemption, at any time prior to the close of business on the second scheduled trading day immediately preceding the redemption date; and • upon the occurrence of specified corporate events (as set forth in the applicable indenture) On or after the applicable Free Convertibility Date until the close of business on the second scheduled trading day immediately preceding the applicable maturity date, holders of the Non-Accreting Notes may convert their Non-Accreting Notes at any time. The following Non-Accreting Notes are convertible during the calendar quarter ended September 30, 2021: the 2022 Notes, the 2024 Notes and the 2026 Notes. The 2025 Notes are not convertible during the third quarter of 2021. The holders of the 2025 Accreting Notes may convert all or a portion of their 2025 Accreting Notes at any time prior to the second business day immediately preceding the maturity date. Wayfair will settle any conversion of 2025 Accreting Notes with a number of shares of Wayfair’s Class A common stock per $1,000 original principal amount of 2025 Accreting Notes equal to the accreted principal amount of such original principal amount of 2025 Accreting Notes divided by the conversion price. Upon the occurrence of a fundamental change (as defined in the applicable indenture), holders of the Notes may require Wayfair to repurchase all or a portion of the Notes for cash at a price equal to 100% of the principal amount (or accreted principal amount) of the Notes to be repurchased plus any accrued but unpaid interest to, but excluding, the fundamental change repurchase date (such interest to be included in the accreted principal amount for the 2025 Accreting Notes). Holders of the Non-Accreting Notes who convert their respective notes in connection with a make-whole fundamental change or a notice of redemption (each as defined in the indenture) may be entitled to a premium in the form of an increase in the conversion rate of the respective notes. Holders of the 2025 Accreting Notes who convert in connection with a make-whole fundamental change (as defined in the applicable indenture) may be entitled to a premium in the form of an increase in the conversion rate. Wayfair may not redeem the Notes prior to certain dates (the “Redemption Date”). On or after the applicable Redemption Date, Wayfair may redeem for cash all or part of the applicable series of Notes if the last reported sale price of Wayfair’s Class A common stock equals or exceeds 130% (Non-Accreting Notes) or 276% (2025 Accreting Notes) of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including at least one of the five trading days immediately preceding the date on which Wayfair provides notice of redemption, during any 30 consecutive trading days ending on, and including the trading day immediately preceding the date on which Wayfair provides notice of the redemption. The redemption price will be either 100% of the principal amount (or accreted principal amount) of the notes to be redeemed, plus accrued and unpaid interest, if any, or the if-converted value holder elects to convert their Notes upon receiving notice of redemption. Conversions of Notes In the three months ended June 30, 2021, holders of the 2022 Notes and 2026 Notes converted $14.5 million of aggregate principal and received 139,196 shares of Wayfair’s Class A common stock. During the six months ended June 30, 2021, holders of the 2022 Notes and 2026 Notes converted $14.9 million of aggregate principal and received 143,440 shares of Wayfair’s Class A common stock. During the six months ended June 30, 2021, Great Hill converted $253.1 million of accreted principal of the 2025 Accreting Notes and received 3,490,175 shares of Wayfair's Class A common stock. In aggregate, these conversions increased additional paid-in capital by $14.4 million and $264.8 million for the three and six months ended June 30, 2021. Interest Expense The following tables present total interest expense recognized for the Notes for the three and six months ended June 30, 2021 and 2020, which included the reversal of interest expense we recorded in 2020 for a portion of interest accretion for the 2025 Accreting Notes that was not realized in 2021: Three Months Ended June 30, 2021 2020 Convertible Notes Contractual Interest Expense Debt Discount Amortization Total Interest Expense Contractual Interest Expense Debt Discount Amortization Total Interest Expense (in thousands) 2022 Notes $ 4 $ 15 $ 19 $ 404 $ 5,289 $ 5,693 2024 Notes 1,617 539 2,156 1,617 7,017 8,634 2026 Notes 2,372 476 2,848 2,372 8,619 10,991 2025 Notes 2,372 845 3,217 — — — 2025 Accreting Notes 223 23 246 3,192 1,685 4,877 Total $ 6,588 $ 1,898 $ 8,486 $ 7,585 $ 22,610 $ 30,195 Six Months Ended June 30, 2021 2020 Convertible Notes Contractual Interest Expense Debt Discount Amortization Total Interest Expense Contractual Interest Expense Debt Discount Amortization Total Interest Expense (in thousands) 2022 Notes $ 23 $ 37 $ 60 $ 809 $ 10,501 $ 11,310 2024 Notes 3,234 1,078 4,312 3,234 13,903 17,137 2026 Notes 4,612 1,083 5,695 4,691 17,154 21,845 2025 Notes 4,744 1,696 6,440 — — — 2025 Accreting Notes (1,157) 76 (1,081) 3,192 1,685 4,877 Total $ 11,456 $ 3,970 $ 15,426 $ 11,926 $ 43,243 $ 55,169 Fair Value of Notes The estimated fair value of the 2022 Notes, 2024 Notes, 2026 Notes, 2025 Notes and 2025 Accreting Notes was $9.4 million, $1.6 billion, $2.1 billion, $1.6 billion and $156.2 million, respectively, as of June 30, 2021. The estimated fair value of the Non-Accreting Notes was determined through consideration of quoted market prices. The estimated fair value of the 2025 Accreting Notes was determined through an option pricing model using Level 3 inputs. The fair values of the Non-Accreting Notes and the 2025 Accreting Notes are classified as Level 2 and Level 3, respectively, as defined in Note 3, Cash and Cash Equivalents, Investments and Fair Value Measurements . The if-converted value of the 2022 Notes, 2024 Notes, 2026 Notes and 2025 Accreting Notes exceeded the principal value by $6.3 million, $984.6 million, $1.1 billion and $120.3 million, respectively, as of June 30, 2021. The if-converted value of the 2025 Notes did not exceed the principal value as of June 30, 2021. Capped Calls The 2022 Capped Calls, 2024 Capped Calls, 2026 Capped Calls and 2025 Capped Calls (collectively, the "Capped Calls") are expected generally to reduce the potential dilution and/or offset the cash payments Wayfair is required to make in excess of the principal amount of the Non-Accreting Notes upon conversion of the Non-Accreting Notes if the market price per share of Wayfair’s Class A common stock is greater than the strike price of the applicable Capped Call (which correspond to the initial conversion price of the applicable Non-Accreting Notes and is subject to certain adjustments under the terms of the applicable Capped Call), with such reduction and/or offset subject to a cap based on the cap price of the applicable Capped Calls (the "Initial Cap Price"). The Capped Calls can, at Wayfair’s option, remain outstanding until their maturity date, even if all or a portion of the Non-Accreting Notes are converted, repurchased or redeemed prior to such date. Each of the Capped Calls has an initial cap price per share of Wayfair’s Class A common stock, which represented a premium over the last reported sale price (or, with respect to the 2025 Capped Calls, the volume-weighted average price) of Wayfair’s Class A common stock on the date the corresponding Non-Accreting Notes were priced (the "Cap Price Premium"), and is subject to certain adjustments under the terms of the corresponding agreements. Collectively, the Capped Calls cover, initially, the number of shares of Wayfair’s Class A common stock underlying the Non-Accreting Notes, subject to anti-dilution adjustments substantially similar to those applicable to the Non-Accreting Notes. The initial terms for the Capped Calls are presented below: Capped Calls Maturity Date Initial Cap Price Cap Price Premium 2022 Capped Calls September 1, 2022 $154.16 100% 2024 Capped Calls November 1, 2024 $219.63 150% 2026 Capped Calls August 15, 2026 $280.15 150% 2025 Capped Calls October 1, 2025 $787.08 150%

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	5. Commitments and Contingencies Legal Matters From time to time Wayfair is involved in claims that arise during the ordinary course of business. Although the results of litigation and claims cannot be predicted with certainty, Wayfair does not currently believe that the outcome of any of these other legal matters will have a material adverse effect on Wayfair's results of operation or financial condition. Regardless of the outcome, litigation can be costly and time consuming, as it can divert management's attention from important business matters and initiatives, negatively impacting Wayfair's overall operations. In addition, Wayfair may also find itself at greater risk to outside party claims as it increases its operations in jurisdictions where the laws with respect to the potential liability of online retailers are uncertain, unfavorable, or unclear. On November 18, 2020, certain of our present and former directors, along with Great Hill Partners, L.P., GHEP VII Aggregator, L.P. (“Great Hill”), Charlesbank Capital Partners, LLC and CBEP Investments, LLC (“Charlesbank”), were named as defendants in a shareholder derivative lawsuit filed in the Court of Chancery of the State of Delaware by the Equity-League Pension Trust Fund. Wayfair is named as a nominal defendant. The derivative complaint primarily alleges that the director defendants breached their fiduciary duties with respect to Wayfair’s issuance of the 2025 Accreting Notes, and further alleges that the non-director defendants were unjustly enriched on the basis of the issuance. The complaint asserts causes of action for breach of fiduciary duty and unjust enrichment and seeks disgorgement of proceeds received as a result of the issuance, other equitable relief and damages and attorneys’ fees and costs. On February 16, 2021, the named director defendants and Wayfair filed motions to dismiss the complaint with prejudice and Great Hill and Charlesbank each filed separate motions to dismiss the complaint. The motions were fully briefed as of May 11, 2021. Oral argument on the motions is scheduled for August 23, 2021. At this time, based on available information regarding this litigation, we are unable to reasonably assess the ultimate outcome of this case or determine an estimate, or a range of estimates, of potential losses.

Stockholders' Deficit

Stockholders' Deficit	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Deficit	6. Stockholders’ Deficit Preferred Stock Wayfair authorized 10,000,000 shares of undesignated preferred stock, $0.001 par value per share, for future issuance. As of June 30, 2021, Wayfair had no shares of undesignated preferred stock issued or outstanding. Common Stock Wayfair authorized 500,000,000 shares of Class A common stock, $0.001 par value per share, and 164,000,000 shares of Class B common stock, $0.001 par value per share, of which 77,013,108 and 72,980,490 shares of Class A common stock and 26,563,837 and 26,564,234 shares of Class B common stock were outstanding as of June 30, 2021 and December 31, 2020. The rights of the holders of Class A common stock and Class B common stock are identical, except for voting and conversion rights. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share. Each share of Class B common stock may be converted into one share of Class A common stock at the option of its holder and will be automatically converted into one share of Class A common stock upon transfer thereof, subject to certain exceptions. In addition, upon the date on which the outstanding shares of Class B common stock represent less than 10% of the aggregate number of shares of the then outstanding Class A common stock and Class B common stock, or in the event of the affirmative vote or written consent of holders of at least 66 2/3% of the outstanding shares of Class B common stock, all outstanding shares of Class B common stock shall convert automatically into Class A common stock. Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of common stock are entitled to receive dividends out of funds legally available if the board of directors (the “Board”), in its discretion, determines to issue dividends and then only at the times and in the amounts that the Board may determine. Since Wayfair's initial public offering through June 30, 2021, 55,474,577 shares of Class B common stock were converted to Class A common stock. Stock Repurchase Program On August 21, 2020, the Board authorized the repurchase of up to $700.0 million of Wayfair’s Class A common stock in the open market, through privately negotiated transactions, or otherwise, including pursuant to a Rule 10b5-1 plan (the “2020 Repurchase Program”). During the three and six months ended June 30, 2021, Wayfair repurchased $300.0 million and $300.2 million through the 2020 Repurchase Program at an average price of $305.50 and $305.43 per share of Class A common stock. During the three and six months ended June 30, 2020, Wayfair did not repurchase any shares of common stock.

Equity-Based Compensation

Equity-Based Compensation	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Equity-Based Compensation	7. Equity-Based Compensation The Board adopted the 2014 Incentive Award Plan ("2014 Plan") to grant cash and equity incentive awards to eligible participants in order to attract, motivate and retain talent. The 2014 Plan is administered by the Board for awards to non-employee directors and by the compensation committee of the Board for other participants and provides for the issuance of stock options, SARs, restricted common stock, restricted stock units ("RSUs"), performance shares, stock payments, cash payments, dividend awards and other incentives. Prior to the adoption of the 2014 Plan, Wayfair LLC issued certain equity awards pursuant to the Wayfair LLC Amended and Restated Common Unit Plan (the "2010 Plan"), which was administered by the Board of Wayfair LLC. Awards issued under the 2010 Plan that remain outstanding currently represent Class A or Class B common stock of Wayfair Inc. The 2014 Plan initially made 8,603,066 shares of Class A common stock available for future award grants. The 2014 Plan also contains an evergreen provision whereby the shares available for future grants are increased on the first day of each calendar year from January 1, 2016 through and including January 1, 2024. As of January 1, 2021, 6,224,792 shares of Class A common stock were available for future grant under the 2014 Plan. Shares or RSUs forfeited, withheld for minimum statutory tax obligations, and unexercised stock option lapses from the 2010 and 2014 Plans are available for future grant under the 2014 Plan. The following table presents activity relating to stock options for the six months ended June 30, 2021: Shares Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Outstanding at December 31, 2020 19,046 $ 2.99 0.5 Options exercised (19,026) $ 2.98 Options forfeited/canceled (20) $ 3.42 Outstanding and exercisable at June 30, 2021 — $ — 0 The intrinsic value of stock options exercised was $5.9 million and $2.2 million for the six months ended June 30, 2021 and 2020. All stock options were fully vested at June 30, 2021. The following table presents activity relating to RSUs for the six months ended June 30, 2021: Shares Weighted- Unvested at December 31, 2020 5,975,299 $ 134.03 RSUs granted 912,628 $ 312.80 RSUs vested (1,362,291) $ 114.63 RSUs forfeited/canceled (467,841) $ 145.88 Outstanding as of June 30, 2021 5,057,795 $ 170.42 The intrinsic value of RSUs vested was $400.5 million and $137.1 million for the six mon ths ended June 30, 2021 and 2020 . The aggregate intrinsic value of RSUs unvested is $1.6 billion as of June 30, 2021. Unrecognized equity-based compensation expense related to RSUs expected to vest over time is $778.6 million with a weighted-average remaining ve sting term of 1.2 years as of June 30, 2021.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The provision for income taxes, net recorded in the three and six months ended June 30, 2021 is primarily related to income earned in the U.S. and certain foreign jurisdictions and U.S. state income taxes, as well as related changes in our valuation allowance on deferred tax assets, offset by a discrete tax benefit related to excess tax benefits on equity awards for U.S. employees. Wayfair had no material unrecognized tax benefits as of June 30, 2021 and December 31, 2020.

Earnings (Loss) per Share

Earnings (Loss) per Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Earnings (Loss) per Share	9. Earnings (Loss) per Share The following table presents the calculation of basic and diluted earnings (loss) per share: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands, except per share data) Numerator: Numerator for basic EPS - Net income (loss) $ 130,428 $ 273,877 $ 148,662 $ (11,988) Effect of dilutive securities: Interest expense associated with convertible debt instruments 8,485 30,195 8,986 — Numerator for diluted EPS - net income (loss) available to common stockholders after the effect of dilutive securities $ 138,913 $ 304,072 $ 157,648 $ (11,988) Denominator: Denominator for basic EPS - weighted-average number of shares of common stock outstanding 103,829 94,834 103,337 94,461 Effect of dilutive securities: Employee stock options 4 31 9 — Restricted stock units 2,722 2,788 3,001 — Convertible debt instruments 15,537 22,279 12,293 — Dilutive potential common shares 18,263 25,098 15,303 — Denominator for diluted EPS - adjusted weighted-average number of shares of common stock outstanding after the effect of dilutive securities 122,092 119,932 118,640 94,461 Earnings (Loss) per Share: Basic $ 1.26 $ 2.89 $ 1.44 $ (0.13) Diluted $ 1.14 $ 2.54 $ 1.33 $ (0.13) The potential common shares from anti-dilutive securities excluded from the weighted-average shares of common stock used to calculate diluted earnings (loss) per share were as follows: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) Outstanding employee stock options — — — 26 Unvested restricted stock units 204 933 129 7,180 Shares related to convertible debt instruments — — 3,639 22,279 Total 204 933 3,768 29,485 Wayfair may settle conversions of the Non-Accreting Notes in cash, shares of Wayfair’s Class A common stock or any combination thereof at its election. Wayfair will settle conversions of the 2025 Accreting Notes in shares. T he Capped Calls are generally expected to reduce the potential dilution of Wayfair's Class A common stock upon any conversion of the Notes and/or offset the cash payments Wayfair is required to make in excess of the principal amount of the Notes upon conversion of the Notes to the extent the market price per share of Wayfair’s Class A common stock is greater than the strike price of the Capped Calls (which corresponds to the initial conversion prices of the Non-Accreting Notes, subject to certain adjustments under the terms of the Capped Calls), with such reduction and/or offset capped at the Initial Cap Price. As of June 30, 2021, the number of shares of Wayfair's Class A common stock potentially issuable at the respective conversion prices of the 2022 Notes, 2024 Notes, 2026 Notes, 2025 Notes and 2025 Accreting Notes is 29,916 shares, 4,939,825 shares, 6,389,703 shares, 3,638,950 shares and 494,733 shares. Under the Capped Calls outstanding as of June 30, 2021, the maximum cash value obtainable of the 2022 Capped Calls, 2024 Capped Calls, 2026 Capped Calls and 2025 Capped Calls, if exercised at maturity, is $207.6 million, $509.9 million, $841.3 million and $1.3 billion. For more information on the structure of the Notes and the Capped Calls, see Note 4, Debt and Other Financing .

Segment and Geographic Informat

Segment and Geographic Information	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Segment and Geographic Information	10. Segment and Geographic Information Operating segments are defined as components of an enterprise for which separate financial information is available that is evaluated on a regular basis by the Chief Operating Decision Maker ("CODM") in deciding how to allocate resources to an individual segment and in assessing performance. Wayfair’s CODM is its Chief Executive Officer. Wayfair's operating and reportable segments are the U.S. and International. These segments reflect the way the CODM allocates resources and evaluates financial performance, which is based upon each segment's Adjusted EBITDA. Adjusted EBITDA is defined as net income (loss) before depreciation and amortization, equity-based compensation and related taxes, interest expense, net, other (expense) income, net, provision for income taxes, net, non-recurring items, and other items not indicative of our ongoing operating performance. These charges are excluded from evaluation of segment performance because it facilitates reportable segment performance comparisons on a period-to-period basis as these costs may vary independent of business performance. Wayfair allocates certain operating expenses to the operating and reportable segments, including customer service and merchant fees and selling, operations, technology, general and administrative based on the usage and relative contribution provided to the segments. It excludes from the allocations certain operating expense lines, including depreciation and amortization, equity-based compensation and related taxes, as well as interest expense, net, other (expense) income, net, and provision for income taxes, net. There are no net revenue transactions between Wayfair's reportable segments. U.S. The U.S. segment primarily consists of amounts earned through product sales through Wayfair's family of sites in the U.S. International The International segment primarily consists of amounts earned through product sales through Wayfair's international sites. Net revenue from external customers for each group of similar products and services are not reported to the CODM. Separate identification of this information for purposes of segment disclosure is impractical, as it is not readily available and the cost to develop it would be excessive. The following tables present net revenues and Adjusted EBITDA attributable to Wayfair's reportable segments for the periods presented: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) U.S. net revenue $ 3,098,157 $ 3,651,704 $ 5,918,843 $ 5,626,687 International net revenue 759,469 652,968 1,416,301 1,008,048 Total net revenue $ 3,857,626 $ 4,304,672 $ 7,335,144 $ 6,634,735 Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) Adjusted EBITDA: U.S. $ 322,561 $ 434,574 $ 549,796 389,479 International (11,721) 5,239 (33,189) (76,943) Total reportable segments Adjusted EBITDA 310,840 439,813 516,607 312,536 Less: reconciling items (1) (180,412) (165,936) (367,945) (324,524) Net income $ 130,428 $ 273,877 $ 148,662 $ (11,988) (1) The following adjustments are made to reconcile total reportable segments Adjusted EBITDA to consolidated net income (loss): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) Depreciation and amortization $ 77,925 $ 69,114 $ 158,237 $ 135,957 Equity-based compensation and related taxes 87,708 70,701 174,609 134,693 Interest expense, net 8,402 28,939 15,214 51,157 Other expense (income), net 2,248 (3,110) 5,546 (2,864) Provision for income taxes, net 4,129 292 2,127 1,625 Other (a) — — 12,212 3,956 Total reconciling items $ 180,412 $ 165,936 $ 367,945 $ 324,524

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	11. Related Party Transactions As discussed in Note 6, Debt and Other Financing, included in Part II, Item 8, Financial Statements and Supplementary Data, of Wayfair’s Annual Report on Form 10-K for the year ended December 31, 2020, in April 2020, pursuant to the terms of the amended and restated purchase agreement, dated April 7, 2020 (the "Purchase Agreement"), Wayfair issued $535.0 million in aggregate original principal amount of 2025 Accreting Notes. The issuance of the 2025 Accreting Notes constitutes a related party transaction because of Michael W. Choe's positions as a director of Wayfair (as of May 12, 2020) and Managing Director and Chief Executive Officer of Charlesbank Capital Partners, LLC, the sole owner of the ultimate general partner of Charlesbank, a party to the Purchase Agreement; Michael Kumin's positions as a director of Wayfair and a Managing Partner at Great Hill Partners, LP, Manager of the ultimate general partner of Great Hill, a party to the Purchase Agreement; and the limited partnership interests held by Niraj Shah and Steve Conine, Wayfair's co-founders and co-chairmen, in affiliates of Great Hill and Charlesbank.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated and condensed financial statements contained in this Quarterly Report on Form 10-Q are those of Wayfair Inc. and its wholly-owned subsidiaries. Unless the context indicates otherwise, references to “we,” “us” and “our” refer to Wayfair Inc. and its subsidiaries. In our opinion, the accompanying unaudited consolidated and condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States ("GAAP") and applicable rules and regulations of the U.S. Securities and Exchange Commission ("SEC") regarding interim financial reporting and reflect all adjustments, consisting of normal recurring adjustments, necessary to present fairly the results of the interim periods presented. Certain information and note disclosures normally included in the audited financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2020. Furthermore, interim results are not necessarily indicative of the results for the full year ended December 31, 2021 or future periods. Wayfair believes that other than the adoption of new accounting pronouncements that follow, there have been no significant changes during the three and six months ended June 30, 2021 to the items disclosed in Note 1, Summary of Significant Accounting Policies , included in Part II, Item 8, Financial Statements and Supplementary Data
Adoption of New Accounting Pronouncements	Adoption of New Accounting Pronouncements Convertible Debt Wayfair adopted ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity (Subtopic 815-40) ("ASU 2020-06") on January 1, 2021 using the modified retrospective approach for all financial instruments that are outstanding as of the adoption date. The new standard eliminates the cash conversion and beneficial conversion feature models that previously required separate accounting for conversion features. Entities that had those conversion features will report less interest expense as those conversion features were recorded as debt discounts which were amortized over the term of the debt. In addition, this ASU requires the application of the if-converted method when calculating diluted earnings per share. Under the new standard, the conversion of debt that is accounted for as a liability in its entirety will not result in any gain or loss if the conversion feature is exercised according to the original conversion terms. If those terms allowed the issuer to include cash as part of the settlement of the conversion feature, the issuer will first reduce the carrying amount of the convertible debt, including any unamortized premium, discount or issuance costs, by the value of the cash or other assets transferred and then recognize the remaining carrying value of the debt in the capital accounts. The adoption of ASU 2020-06 resulted in the following adjustments to the consolidated and condensed balance sheets: January 1, 2021 Adoption of ASU 2020-06 December 31, 2020 (in thousands) Balance sheet line item: Long-term debt $ 3,310,065 $ 650,822 $ 2,659,243 Other non-current liabilities $ 46,413 $ (20,618) $ 67,031 Additional paid-in capital $ — $ (698,482) $ 698,482 Accumulated deficit $ (1,817,671) $ 68,279 $ (1,885,950) The adoption of ASU 2020-06 resulted in the following adjustments to our calculations of basic and diluted earnings per share for the three months ended June 30, 2021: Under ASU 2020-06 Difference Under Legacy Accounting Earnings (loss) per share: Basic $ 1.26 $ 0.28 $ 0.98 Diluted $ 1.14 $ 0.19 $ 0.95 The adoption of ASU 2020-06 resulted in the following adjustments to our calculations of basic and diluted earnings per share for the six months ended June 30, 2021: Under ASU 2020-06 Difference Under Legacy Accounting Earnings (loss) per share: Basic $ 1.44 $ 0.76 $ 0.68 Diluted $ 1.33 $ 0.67 $ 0.66 The adoption of ASU 2020-06 did not materially impact our cash flows or compliance with debt covenants. Income Taxes Wayfair adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ ASU 2019-12”) on January 1, 2021, using the modified retrospective approach. This ASU simplifies the accounting for income taxes, removes certain exceptions to the general principles in Topic 740, and clarifies and amends existing guidance to improve consistent application. The effect of adoption of the new guidance was not material to our consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Schedule of Adoption of ASU 2020-06	The adoption of ASU 2020-06 resulted in the following adjustments to the consolidated and condensed balance sheets: January 1, 2021 Adoption of ASU 2020-06 December 31, 2020 (in thousands) Balance sheet line item: Long-term debt $ 3,310,065 $ 650,822 $ 2,659,243 Other non-current liabilities $ 46,413 $ (20,618) $ 67,031 Additional paid-in capital $ — $ (698,482) $ 698,482 Accumulated deficit $ (1,817,671) $ 68,279 $ (1,885,950) The adoption of ASU 2020-06 resulted in the following adjustments to our calculations of basic and diluted earnings per share for the three months ended June 30, 2021: Under ASU 2020-06 Difference Under Legacy Accounting Earnings (loss) per share: Basic $ 1.26 $ 0.28 $ 0.98 Diluted $ 1.14 $ 0.19 $ 0.95 The adoption of ASU 2020-06 resulted in the following adjustments to our calculations of basic and diluted earnings per share for the six months ended June 30, 2021: Under ASU 2020-06 Difference Under Legacy Accounting Earnings (loss) per share: Basic $ 1.44 $ 0.76 $ 0.68 Diluted $ 1.33 $ 0.67 $ 0.66 The adoption of ASU 2020-06 did not materially impact our cash flows or compliance with debt covenants.

Cash and Cash Equivalents, In_2

Cash and Cash Equivalents, Investments, and Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Marketable Securities	The following tables present details of Wayfair’s investment securities as of June 30, 2021 and December 31, 2020: June 30, 2021 Amortized Gross Gross Estimated (in thousands) Short-term: Investment securities $ 523,428 $ 4 $ (42) $ 523,390 December 31, 2020 Amortized Gross Unrealized Gains Gross Estimated (in thousands) Short-term: Investment securities $ 461,683 $ 20 $ (5) $ 461,698
Schedule of the Fair Value of the Company's Financial Assets Measured at Fair Value on a Recurring Basis Based on the Three-Tier Value Hierarchy	The following tables set forth the fair value of Wayfair’s financial assets measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020: June 30, 2021 Level 1 Level 2 Level 3 Total (in thousands) Cash and cash equivalents: Cash $ 437,502 $ — $ — $ 437,502 Cash equivalents 1,640,949 — — 1,640,949 Total cash and cash equivalents 2,078,451 — — 2,078,451 Short-term investments: Investment securities — 523,390 — 523,390 Other non-current assets: Certificate of deposit 5,200 — — 5,200 Total $ 2,083,651 $ 523,390 $ — $ 2,607,041 December 31, 2020 Level 1 Level 2 Level 3 Total (in thousands) Cash and cash equivalents: Cash $ 638,621 $ — $ — $ 638,621 Cash equivalents 1,490,819 — — 1,490,819 Total cash and cash equivalents 2,129,440 — — 2,129,440 Short-term investments: Investment securities — 461,698 — 461,698 Other non-current assets: Certificate of deposit 5,200 — — 5,200 Total $ 2,134,640 $ 461,698 $ — $ 2,596,338

Debt and Other Financing (Table

Debt and Other Financing (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Schedule of Outstanding Principal and Carrying Value	The following table presents the outstanding principal amount and carrying value of debt and other financing as of the dates presented: June 30, 2021 December 31, 2020 Debt Instrument Principal Amount Unamortized Debt Discount Net Carrying Amount Principal Amount Unamortized Debt Discount Net Carrying Amount (in thousands) 2022 Notes $ 3,113 $ (14) $ 3,099 $ 18,036 $ (1,596) $ 16,440 2024 Notes 575,000 (7,404) 567,596 575,000 (132,892) 442,108 2026 Notes 948,745 (10,090) 938,655 948,750 (242,911) 705,839 2025 Notes 1,518,000 (14,849) 1,503,151 1,518,000 (289,954) 1,228,046 2025 Accreting Notes 35,868 (386) 35,482 288,464 (21,654) 266,810 Total Debt $ 3,047,983 $ 2,659,243 Short-term debt $ — $ — Long-term debt $ 3,047,983 $ 2,659,243
Schedule of Convertible Notes	The following table summarizes certain terms related to our outstanding convertible notes, excluding the 2025 Accreting Notes: Convertible Non-Accreting Notes Maturity Date Annual Coupon Rate Annual Effective Interest Rate Payment Dates for Semi-Annual Interest Payments in Arrears 2022 Notes September 1, 2022 0.375% 0.9% March 1 and September 1 2024 Notes November 1, 2024 1.125% 1.5% May 1 and November 1 2026 Notes August 15, 2026 1.000% 1.2% February 15 and August 15 2025 Notes October 1, 2025 0.625% 0.9% April 1 and October 1 Wayfair's Notes will mature at their maturity date unless earlier purchased, redeemed or converted. The Notes’ initial conversion terms are summarized below: Convertible Notes Maturity Date Free Convertibility Date Initial Conversion Rate per $1,000 Principal Initial Conversion Price Redemption Date 2022 Notes September 1, 2022 June 1, 2022 9.6100 $104.06 September 8, 2020 2024 Notes November 1, 2024 August 1, 2024 8.5910 $116.40 May 8, 2022 2026 Notes August 15, 2026 May 15, 2026 6.7349 $148.48 August 20, 2023 2025 Notes October 1, 2025 July 1, 2025 2.3972 $417.15 October 4, 2022 2025 Accreting Notes April 1, 2025 - 13.7931 $72.50 May 9, 2023
Schedule of Interest Expense Related to Notes	The following tables present total interest expense recognized for the Notes for the three and six months ended June 30, 2021 and 2020, which included the reversal of interest expense we recorded in 2020 for a portion of interest accretion for the 2025 Accreting Notes that was not realized in 2021: Three Months Ended June 30, 2021 2020 Convertible Notes Contractual Interest Expense Debt Discount Amortization Total Interest Expense Contractual Interest Expense Debt Discount Amortization Total Interest Expense (in thousands) 2022 Notes $ 4 $ 15 $ 19 $ 404 $ 5,289 $ 5,693 2024 Notes 1,617 539 2,156 1,617 7,017 8,634 2026 Notes 2,372 476 2,848 2,372 8,619 10,991 2025 Notes 2,372 845 3,217 — — — 2025 Accreting Notes 223 23 246 3,192 1,685 4,877 Total $ 6,588 $ 1,898 $ 8,486 $ 7,585 $ 22,610 $ 30,195 Six Months Ended June 30, 2021 2020 Convertible Notes Contractual Interest Expense Debt Discount Amortization Total Interest Expense Contractual Interest Expense Debt Discount Amortization Total Interest Expense (in thousands) 2022 Notes $ 23 $ 37 $ 60 $ 809 $ 10,501 $ 11,310 2024 Notes 3,234 1,078 4,312 3,234 13,903 17,137 2026 Notes 4,612 1,083 5,695 4,691 17,154 21,845 2025 Notes 4,744 1,696 6,440 — — — 2025 Accreting Notes (1,157) 76 (1,081) 3,192 1,685 4,877 Total $ 11,456 $ 3,970 $ 15,426 $ 11,926 $ 43,243 $ 55,169
Schedule of Initial Terms for Capped Calls	The initial terms for the Capped Calls are presented below: Capped Calls Maturity Date Initial Cap Price Cap Price Premium 2022 Capped Calls September 1, 2022 $154.16 100% 2024 Capped Calls November 1, 2024 $219.63 150% 2026 Capped Calls August 15, 2026 $280.15 150% 2025 Capped Calls October 1, 2025 $787.08 150%

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Activity Relating to Stock Options	The following table presents activity relating to stock options for the six months ended June 30, 2021: Shares Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Outstanding at December 31, 2020 19,046 $ 2.99 0.5 Options exercised (19,026) $ 2.98 Options forfeited/canceled (20) $ 3.42 Outstanding and exercisable at June 30, 2021 — $ — 0
Schedule of Activity Relating to Restricted Stock Units	The following table presents activity relating to RSUs for the six months ended June 30, 2021: Shares Weighted- Unvested at December 31, 2020 5,975,299 $ 134.03 RSUs granted 912,628 $ 312.80 RSUs vested (1,362,291) $ 114.63 RSUs forfeited/canceled (467,841) $ 145.88 Outstanding as of June 30, 2021 5,057,795 $ 170.42

Earnings (Loss) per Share (Tabl

Earnings (Loss) per Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Schedule of Calculation of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted earnings (loss) per share: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands, except per share data) Numerator: Numerator for basic EPS - Net income (loss) $ 130,428 $ 273,877 $ 148,662 $ (11,988) Effect of dilutive securities: Interest expense associated with convertible debt instruments 8,485 30,195 8,986 — Numerator for diluted EPS - net income (loss) available to common stockholders after the effect of dilutive securities $ 138,913 $ 304,072 $ 157,648 $ (11,988) Denominator: Denominator for basic EPS - weighted-average number of shares of common stock outstanding 103,829 94,834 103,337 94,461 Effect of dilutive securities: Employee stock options 4 31 9 — Restricted stock units 2,722 2,788 3,001 — Convertible debt instruments 15,537 22,279 12,293 — Dilutive potential common shares 18,263 25,098 15,303 — Denominator for diluted EPS - adjusted weighted-average number of shares of common stock outstanding after the effect of dilutive securities 122,092 119,932 118,640 94,461 Earnings (Loss) per Share: Basic $ 1.26 $ 2.89 $ 1.44 $ (0.13) Diluted $ 1.14 $ 2.54 $ 1.33 $ (0.13)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The potential common shares from anti-dilutive securities excluded from the weighted-average shares of common stock used to calculate diluted earnings (loss) per share were as follows: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) Outstanding employee stock options — — — 26 Unvested restricted stock units 204 933 129 7,180 Shares related to convertible debt instruments — — 3,639 22,279 Total 204 933 3,768 29,485

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Schedule of Activity Related to Net Revenue and Adjusted EBITDA	The following tables present net revenues and Adjusted EBITDA attributable to Wayfair's reportable segments for the periods presented: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) U.S. net revenue $ 3,098,157 $ 3,651,704 $ 5,918,843 $ 5,626,687 International net revenue 759,469 652,968 1,416,301 1,008,048 Total net revenue $ 3,857,626 $ 4,304,672 $ 7,335,144 $ 6,634,735 Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) Adjusted EBITDA: U.S. $ 322,561 $ 434,574 $ 549,796 389,479 International (11,721) 5,239 (33,189) (76,943) Total reportable segments Adjusted EBITDA 310,840 439,813 516,607 312,536 Less: reconciling items (1) (180,412) (165,936) (367,945) (324,524) Net income $ 130,428 $ 273,877 $ 148,662 $ (11,988) (1) The following adjustments are made to reconcile total reportable segments Adjusted EBITDA to consolidated net income (loss): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 (in thousands) Depreciation and amortization $ 77,925 $ 69,114 $ 158,237 $ 135,957 Equity-based compensation and related taxes 87,708 70,701 174,609 134,693 Interest expense, net 8,402 28,939 15,214 51,157 Other expense (income), net 2,248 (3,110) 5,546 (2,864) Provision for income taxes, net 4,129 292 2,127 1,625 Other (a) — — 12,212 3,956 Total reconciling items $ 180,412 $ 165,936 $ 367,945 $ 324,524

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Adoption of ASU 2020-06 (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jan. 01, 2021	Dec. 31, 2020
Balance sheet line item:
Long-term debt	$ 3,047,983		$ 3,047,983		$ 3,310,065	$ 2,659,243
Other non-current liabilities	50,058		50,058		46,413	67,031
Additional paid-in capital	131,706		131,706		0	698,482
Accumulated deficit	$ (1,669,009)		$ (1,669,009)		$ (1,817,671)	(1,885,950)
Earnings (loss) per share:
Basic (in usd per share)	$ 1.26	$ 2.89	$ 1.44	$ (0.13)
Diluted (in usd per share)	1.14	$ 2.54	1.33	$ (0.13)
Difference
Earnings (loss) per share:
Basic (in usd per share)	0.28		0.76
Diluted (in usd per share)	0.19		0.67
Under Legacy Accounting
Earnings (loss) per share:
Basic (in usd per share)	0.98		0.68
Diluted (in usd per share)	$ 0.95		$ 0.66
Adoption of ASU 2020-06
Balance sheet line item:
Long-term debt						650,822
Other non-current liabilities						(20,618)
Additional paid-in capital						(698,482)
Accumulated deficit						$ 68,279

Supplemental Financial Statem_2

Supplemental Financial Statement Disclosures - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Supplemental Financial Statement Disclosures [Abstract]
Accounts receivable, net	$ 129,410	$ 129,410	$ 110,299
Accounts receivable allowance for credit losses	$ 18,700	$ 18,700	$ 21,400
Revenue, collection in advance of recognition (in percentage)	99.00%	99.00%

Supplemental Financial Statem_3

Supplemental Financial Statement Disclosures - Contractual Liabilities (Details) - Unearned revenue - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Other Current Liabilities
Contract liabilities	$ 317	$ 298.1
Revenue recognized that was included in deferred revenue	$ 234.1

Supplemental Financial Statem_4

Supplemental Financial Statement Disclosures - Customer Service Center Impairment and Other Charges (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Supplemental Financial Statement Disclosures [Abstract]
Customer service center impairment and other charges	$ 0	$ 12,200	$ 0	$ 12,212	$ 0
Impairment of right-of-use (“ROU”) assets		6,300
Accelerated depreciation of fixed assets		$ 5,000

Cash and Cash Equivalents, In_3

Cash and Cash Equivalents, Investments, and Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jul. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Realized gains or losses	$ 0	$ 0	$ 0	$ 0
Debt securities, available-for-sale, realized gain				800,000
Credit losses recognized	0	$ 0	0	0
Allowance for credit losses	0		0			$ 0
Other equity investments	$ 20,000,000		$ 20,000,000
Subsequent Event
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Equity method investments					$ 5,000,000
Long-term Investment securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Proceeds from sale of investments				$ 161,300,000
Warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Vesting period	5 years
Payments to acquire other investments	$ 5,800,000

Cash and Cash Equivalents, In_4

Cash and Cash Equivalents, Investments, and Fair Value Measurements - Schedule of Marketable Securities (Details) - Short-term Investment securities - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair value measurements
Amortized Cost	$ 523,428	$ 461,683
Gross Unrealized Gains	4	20
Gross Unrealized Losses	(42)	(5)
Estimated Fair Value	$ 523,390	$ 461,698

Cash and Cash Equivalents, In_5

Cash and Cash Equivalents, Investments, and Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair value measurements
Cash and cash equivalents	$ 2,078,451	$ 2,129,440
Total	2,607,041	2,596,338
Level 1
Fair value measurements
Cash and cash equivalents	2,078,451	2,129,440
Total	2,083,651	2,134,640
Level 2
Fair value measurements
Cash and cash equivalents	0	0
Total	523,390	461,698
Level 3
Fair value measurements
Cash and cash equivalents	0	0
Total	0	0
Investment securities
Fair value measurements
Short-term investments	523,390	461,698
Investment securities | Level 1
Fair value measurements
Short-term investments	0	0
Investment securities | Level 2
Fair value measurements
Short-term investments	523,390	461,698
Investment securities | Level 3
Fair value measurements
Short-term investments	0	0
Certificate of deposit
Fair value measurements
Other non-current assets	5,200	5,200
Certificate of deposit | Level 1
Fair value measurements
Other non-current assets	5,200	5,200
Certificate of deposit | Level 2
Fair value measurements
Other non-current assets	0	0
Certificate of deposit | Level 3
Fair value measurements
Other non-current assets	0	0
Cash
Fair value measurements
Cash and cash equivalents	437,502	638,621
Cash | Level 1
Fair value measurements
Cash and cash equivalents	437,502	638,621
Cash | Level 2
Fair value measurements
Cash and cash equivalents	0	0
Cash | Level 3
Fair value measurements
Cash and cash equivalents	0	0
Cash equivalents
Fair value measurements
Cash and cash equivalents	1,640,949	1,490,819
Cash equivalents | Level 1
Fair value measurements
Cash and cash equivalents	1,640,949	1,490,819
Cash equivalents | Level 2
Fair value measurements
Cash and cash equivalents	0	0
Cash equivalents | Level 3
Fair value measurements
Cash and cash equivalents	$ 0	$ 0

Debt and Other Financing - Sche

Debt and Other Financing - Schedule of Outstanding Principal Amount and Carrying Value of Notes (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jan. 01, 2021	Dec. 31, 2020
Debt Instrument
Long-term Debt, Total	$ 3,047,983	$ 3,310,065	$ 2,659,243
Convertible Debt
Debt Instrument
Long-term Debt, Total	3,047,983		2,659,243
Short-term debt	0		0
Convertible Debt | 2022 Notes
Debt Instrument
Principal Amount	3,113		18,036
Unamortized Debt Discount	(14)		(1,596)
Long-term Debt, Total	3,099		16,440
Convertible Debt | 2024 Notes
Debt Instrument
Principal Amount	575,000		575,000
Unamortized Debt Discount	(7,404)		(132,892)
Long-term Debt, Total	567,596		442,108
Convertible Debt | 2026 Notes
Debt Instrument
Principal Amount	948,745		948,750
Unamortized Debt Discount	(10,090)		(242,911)
Long-term Debt, Total	938,655		705,839
Convertible Debt | 2025 Notes
Debt Instrument
Principal Amount	1,518,000		1,518,000
Unamortized Debt Discount	(14,849)		(289,954)
Long-term Debt, Total	1,503,151		1,228,046
Convertible Debt | 2025 Accreting Notes
Debt Instrument
Principal Amount	35,868		288,464
Unamortized Debt Discount	(386)		(21,654)
Long-term Debt, Total	$ 35,482		$ 266,810

Debt and Other Financing - Narr

Debt and Other Financing - Narrative (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2021USD ($)shares	Jun. 30, 2021USD ($)dayshares	Mar. 24, 2021USD ($)	Jan. 01, 2021USD ($)	Dec. 31, 2020USD ($)
Debt Instrument
Long-term debt	$ 3,047,983,000	$ 3,047,983,000		$ 3,310,065,000	$ 2,659,243,000
Convertible Debt
Debt Instrument
Long-term debt	$ 3,047,983,000	$ 3,047,983,000			2,659,243,000
Senior Secured Revolving Credit Facility
Debt Instrument
EBITDA ratio (in percentage)		4
Subject to step-up permitted acquisition Ratio (in percentage)		0.5
2025 Accreting Notes
Debt Instrument
Annual effective interest rate (in percentage)	2.70%	2.70%
2025 Accreting Notes | Convertible Debt
Debt Instrument
Long-term debt	$ 35,482,000	$ 35,482,000			266,810,000
Annual coupon rate (in percentage)	2.50%	2.50%
Number of trading days (whether or not consecutive) | day		20
Number of trading days (consecutive) | day		30
Debt conversion stock price (in percentage)		276.00%
Principal amount of notes		$ 1,000
Principal amount to be redeemed (in percentage)		100.00%
Debt, fair value	$ 156,200,000	$ 156,200,000
Convertible debt, if-converted value in excess of principal		120,300,000
2025 Accreting Notes | Convertible Debt | Class A common stock
Debt Instrument
Debt conversion, increased additional paid in capital	14,400,000	264,800,000
2025 Accreting Notes | Convertible Debt | Charlesbank | Class A common stock
Debt Instrument
Debt conversion, principal amount	$ 14,500,000	$ 14,900,000
Debt conversion, converted, shares issued (in shares) | shares	139,196	143,440
2025 Accreting Notes | Convertible Debt | Great Hill | Class A common stock
Debt Instrument
Debt conversion, principal amount		$ 253,100,000
Debt conversion, converted, shares issued (in shares) | shares		3,490,175
Non-Accreting Notes | Convertible Debt
Debt Instrument
Number of trading days (whether or not consecutive) | day		20
Number of trading days (consecutive) | day		30
Debt conversion stock price (in percentage)		130.00%
Convertible debt business period (in days)		5 days
Consecutive debt measurement period (in days)		10 days
Principal amount of notes		$ 1,000
Measurement period, percentage (less than)		98.00%
2022 Notes | Convertible Debt
Debt Instrument
Long-term debt	$ 3,099,000	$ 3,099,000			16,440,000
Annual coupon rate (in percentage)	0.375%	0.375%
Annual effective interest rate (in percentage)	0.90%	0.90%
Debt, fair value	$ 9,400,000	$ 9,400,000
Convertible debt, if-converted value in excess of principal		6,300,000
2024 Notes | Convertible Debt
Debt Instrument
Long-term debt	$ 567,596,000	$ 567,596,000			442,108,000
Annual coupon rate (in percentage)	1.125%	1.125%
Annual effective interest rate (in percentage)	1.50%	1.50%
Debt, fair value	$ 1,600,000,000	$ 1,600,000,000
Convertible debt, if-converted value in excess of principal		984,600,000
2026 Notes | Convertible Debt
Debt Instrument
Long-term debt	$ 938,655,000	$ 938,655,000			705,839,000
Annual coupon rate (in percentage)	1.00%	1.00%
Annual effective interest rate (in percentage)	1.20%	1.20%
Debt, fair value	$ 2,100,000,000	$ 2,100,000,000
Convertible debt, if-converted value in excess of principal		1,100,000,000
2025 Notes | Convertible Debt
Debt Instrument
Long-term debt	$ 1,503,151,000	$ 1,503,151,000			$ 1,228,046,000
Annual coupon rate (in percentage)	0.625%	0.625%
Annual effective interest rate (in percentage)	0.90%	0.90%
Debt, fair value	$ 1,600,000,000	$ 1,600,000,000
Revolving Credit Facility
Debt Instrument
Borrower and guarantor obligations under debt agreement, capital stock of first-tier foreign subsidiaries (in percentage)		65.00%
Annual effective interest rate (in percentage)	0.05%	0.05%
Revolving Credit Facility | LIBOR
Debt Instrument
Basis spread (in percentage)		1.00%
Applicable margin (in percentage)		0.0125
Revolving Credit Facility | Base Rate
Debt Instrument
Applicable margin (in percentage)		0.0025
Revolving Credit Facility | Senior Secured Revolving Credit Facility
Debt Instrument
Maximum borrowing capacity			$ 600,000,000
Long-term debt	$ 60,200,000	$ 60,200,000
Replaced Revolver | Senior Secured Revolving Credit Facility
Debt Instrument
Maximum borrowing capacity			$ 200,000,000

Debt and Other Financing - Conv

Debt and Other Financing - Convertible Non-Accreting Notes (Details) - Convertible Debt	Jun. 30, 2021
2022 Notes
Debt Instrument
Annual coupon rate (in percentage)	0.375%
Annual effective interest rate (in percentage)	0.90%
2024 Notes
Debt Instrument
Annual coupon rate (in percentage)	1.125%
Annual effective interest rate (in percentage)	1.50%
2026 Notes
Debt Instrument
Annual coupon rate (in percentage)	1.00%
Annual effective interest rate (in percentage)	1.20%
2025 Notes
Debt Instrument
Annual coupon rate (in percentage)	0.625%
Annual effective interest rate (in percentage)	0.90%

Debt and Other Financing - Co_2

Debt and Other Financing - Conversion and Redemption Terms of the Notes (Details) - Convertible Debt	6 Months Ended
	Jun. 30, 2021$ / shares
2022 Notes
Debt Instrument
Debt instrument, convertible, conversion ratio	0.00961
Initial Conversion Price (in usd per share)	$ 104.06
2024 Notes
Debt Instrument
Debt instrument, convertible, conversion ratio	0.008591
Initial Conversion Price (in usd per share)	$ 116.40
2026 Notes
Debt Instrument
Debt instrument, convertible, conversion ratio	0.0067349
Initial Conversion Price (in usd per share)	$ 148.48
2025 Notes
Debt Instrument
Debt instrument, convertible, conversion ratio	0.0023972
Initial Conversion Price (in usd per share)	$ 417.15
2025 Accreting Notes
Debt Instrument
Debt instrument, convertible, conversion ratio	0.0137931
Initial Conversion Price (in usd per share)	$ 72.50

Debt and Other Financing - Sc_2

Debt and Other Financing - Schedule of Interest Expense Related to Notes (Details) - Convertible Debt - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Instrument
Contractual Interest Expense	$ 6,588	$ 7,585	$ 11,456	$ 11,926
Debt Discount Amortization	1,898	22,610	3,970	43,243
Total Interest Expense	8,486	30,195	15,426	55,169
2022 Notes
Debt Instrument
Contractual Interest Expense	4	404	23	809
Debt Discount Amortization	15	5,289	37	10,501
Total Interest Expense	19	5,693	60	11,310
2024 Notes
Debt Instrument
Contractual Interest Expense	1,617	1,617	3,234	3,234
Debt Discount Amortization	539	7,017	1,078	13,903
Total Interest Expense	2,156	8,634	4,312	17,137
2026 Notes
Debt Instrument
Contractual Interest Expense	2,372	2,372	4,612	4,691
Debt Discount Amortization	476	8,619	1,083	17,154
Total Interest Expense	2,848	10,991	5,695	21,845
2025 Notes
Debt Instrument
Contractual Interest Expense	2,372	0	4,744	0
Debt Discount Amortization	845	0	1,696	0
Total Interest Expense	3,217	0	6,440	0
2025 Accreting Notes
Debt Instrument
Contractual Interest Expense	223	3,192	(1,157)	3,192
Debt Discount Amortization	23	1,685	76	1,685
Total Interest Expense	$ 246	$ 4,877	$ (1,081)	$ 4,877

Debt and Other Financing - Sc_3

Debt and Other Financing - Schedule of Initial Terms for Capped Calls (Details) - Convertible Debt - Class A common stock	6 Months Ended
	Jun. 30, 2021$ / shares
2022 Capped Calls
Debt Instrument
Initial Cap Price (usd dollars per share)	$ 154.16
Cap Price Premium (as percentage)	100.00%
2024 Capped Calls
Debt Instrument
Initial Cap Price (usd dollars per share)	$ 219.63
Cap Price Premium (as percentage)	150.00%
2026 Capped Calls
Debt Instrument
Initial Cap Price (usd dollars per share)	$ 280.15
Cap Price Premium (as percentage)	150.00%
2025 Capped Calls
Debt Instrument
Initial Cap Price (usd dollars per share)	$ 787.08
Cap Price Premium (as percentage)	150.00%

Stockholders' Deficit (Details)

Stockholders' Deficit (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2021USD ($)$ / sharesshares	Jun. 30, 2021USD ($)vote$ / sharesshares	Dec. 31, 2020$ / sharesshares	Aug. 21, 2020USD ($)
Preferred stock
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Stock Repurchase Program
Treasury stock, value, acquired, cost method | $	$ (300,020,000)	$ (300,208,000)
Stock repurchase program, average repurchase price per share (in dollars per share) | $ / shares	$ 305.50	$ 305.43
2025 Notes | Convertible Debt
Stock Repurchase Program
Treasury stock, value, acquired, cost method | $	$ (300,000,000)	$ (300,200,000)
Class A common stock
Common stock
Common stock, shares authorized (in shares)	500,000,000	500,000,000	500,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001	$ 0.001
Common stock, shares outstanding (in shares)	77,013,108	77,013,108	72,980,490
Number of votes each holder is entitled | vote		1
Stock Repurchase Program
Repurchase authorized amount | $				$ 700,000,000
Class B common stock
Common stock
Common stock, shares authorized (in shares)	164,000,000	164,000,000	164,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001	$ 0.001
Common stock, shares outstanding (in shares)	26,563,837	26,563,837	26,564,234
Number of votes each holder is entitled | vote		10
Conversion ratio		1
Conversion ratio upon transfer		1
Number of shares converted into Class A common stock (in shares)		55,474,577
Class B common stock | Maximum
Common stock
Aggregate number of shares outstanding Class A common stock and Class B common stock that shall convert automatically (in dollars per share)		10.00%
Class B common stock | Minimum
Common stock
Percentage of outstanding shares of Class B common stock that shall convert automatically in the event of the affirmative vote or written consent of holders		66.67%

Equity-Based Compensation - Nar

Equity-Based Compensation - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jan. 01, 2021	Dec. 31, 2014
Employee stock options
Equity based compensation
Intrinsic value of stock options exercised	$ 5.9	$ 2.2
Restricted stock units
Equity based compensation
Intrinsic value of stock vested	400.5	$ 137.1
Aggregate intrinsic value of stock unvested	1,600
Unrecognized equity-based compensation	$ 778.6
Weighted average remaining vesting term	1 year 2 months 12 days
2014 Plan
Equity based compensation
Number of shares available for future grant (in shares)			6,224,792	8,603,066

Equity-Based Compensation - Sum

Equity-Based Compensation - Summary of Activity Relating to Stock Options (Details) - Employee stock options - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Shares
Outstanding at the beginning of the period (in shares)	19,046
Options exercised (in shares)	(19,026)
Options forfeited/canceled (in shares)	(20)
Outstanding and exercisable at the end of the period (in shares)	0	19,046
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 2.99
Options exercised (in dollars per share)	2.98
Options forfeited/canceled (in dollars per share)	3.42
Outstanding and exercisable at the end of the period (in dollars per share)	$ 0	$ 2.99
Weighted-Average Remaining Contractual Term (Years)
Outstanding		6 months
Exercisable at the end of the period	0 days

Equity-Based Compensation - S_2

Equity-Based Compensation - Summary of Activity Relating to Restricted Stock (Details) - Restricted stock units	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Shares
Unvested at the beginning of the period (in shares) | shares	5,975,299
RSUs granted (in shares) | shares	912,628
RSUs vested (in shares) | shares	(1,362,291)
RSUs forfeited/canceled (in shares) | shares	(467,841)
Unvested at the end of the period (in shares) | shares	5,057,795
Weighted- Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share) | $ / shares	$ 134.03
RSUs granted (in dollars per share) | $ / shares	312.80
RSUs vested (in dollars per share) | $ / shares	114.63
RSUs forfeited/canceled (in dollars per share) | $ / shares	145.88
Unvested at the end of the period (in dollars per share) | $ / shares	$ 170.42

Income Taxes (Details)

Income Taxes (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0	$ 0

Earnings (Loss) per Share - Cal

Earnings (Loss) per Share - Calculation of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Numerator for basic EPS - Net income (loss)	$ 130,428	$ 273,877	$ 148,662	$ (11,988)
Effect of dilutive securities:
Interest expense associated with convertible debt instruments	8,485	30,195	8,986	0
Numerator for diluted EPS - net income (loss) available to common stockholders after the effect of dilutive securities	138,913	304,072	157,648	(11,988)
Numerator for diluted EPS - net income (loss) available to common stockholders after the effect of dilutive securities	$ 138,913	$ 304,072	$ 157,648	$ (11,988)
Denominator:
Denominator for basic EPS - weighted average number of shares of common stock outstanding (in shares)	103,829	94,834	103,337	94,461
Effect of dilutive securities:
Convertible debt instruments (in shares)	15,537	22,279	12,293	0
Dilutive potential common shares (in shares)	18,263	25,098	15,303	0
Denominator for diluted EPS - adjusted weighted-average number of shares of common stock outstanding after the effect of dilutive securities (in shares)	122,092	119,932	118,640	94,461
Earnings (loss) per share:
Basic (in usd per share)	$ 1.26	$ 2.89	$ 1.44	$ (0.13)
Diluted (in usd per share)	$ 1.14	$ 2.54	$ 1.33	$ (0.13)
Employee stock options
Effect of dilutive securities:
Incremental common shares attributable to dilutive effect of share-based payment award (in shares)	4	31	9	0
Restricted stock units
Effect of dilutive securities:
Incremental common shares attributable to dilutive effect of share-based payment award (in shares)	2,722	2,788	3,001	0

Earnings (Loss) per Share - Ant

Earnings (Loss) per Share - Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)	204	933	3,768	29,485
Outstanding employee stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)	0	0	0	26
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)	204	933	129	7,180
Shares related to convertible debt instruments
Antidilutive Securities Excluded from Computation of Earnings Per Share
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)	0	0	3,639	22,279

Earnings (Loss) per Share - Nar

Earnings (Loss) per Share - Narrative (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)	204,000	933,000	3,768,000	29,485,000
Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)	0	0	3,639,000	22,279,000
A 2022 Notes Transaction | Class A common stock | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			29,916
A 2024 Notes Transaction | Class A common stock | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			4,939,825
A 2026 Notes Transaction | Class A common stock | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			6,389,703
A 2025 Notes Transaction | Class A common stock | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			3,638,950
2025 Accreting Notes | Class A common stock | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			494,733
A 2022 Capped Call Transactions | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			207,600,000
A 2024 Capped Call Transactions | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			509,900,000
A 2026 Capped Call Transactions | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			841,300,000
A 2025 Capped Call Transactions | Convertible Debt Securities
Class of Stock
Common stock outstanding that have been excluded from the computation of diluted earnings (loss) per share (in shares)			1,300,000,000

Segment and Geographic Inform_3

Segment and Geographic Information - Net Revenues and Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information
Net revenue	$ 3,857,626		$ 4,304,672	$ 7,335,144	$ 6,634,735
Adjusted EBITDA	310,840		439,813	516,607	312,536
Less: reconciling items	(180,412)		(165,936)	(367,945)	(324,524)
Net income	130,428		273,877	148,662	(11,988)
Depreciation and amortization	77,925		69,114	158,237	135,957
Equity-based compensation and related taxes	87,708		70,701	174,609	134,693
Interest expense, net	8,402		28,939	15,214	51,157
Other expense (income), net	2,248		(3,110)	5,546	(2,864)
Provision for income taxes, net	4,129		292	2,127	1,625
Other	0		0	12,212	3,956
Total reconciling items	180,412		165,936	367,945	324,524
Customer service center impairment and other charges	0	$ 12,200	0	12,212	0
Selling, operations, technology, general and administrative	486,448		459,482	937,817	935,450
Employee Severance
Segment Reporting Information
Selling, operations, technology, general and administrative					4,000
U.S.
Segment Reporting Information
Net revenue	3,098,157		3,651,704	5,918,843	5,626,687
Adjusted EBITDA	322,561		434,574	549,796	389,479
International
Segment Reporting Information
Net revenue	759,469		652,968	1,416,301	1,008,048
Adjusted EBITDA	$ (11,721)		$ 5,239	$ (33,189)	$ (76,943)

Related Party Transactions (Det

Related Party Transactions (Details) - 2025 Accreting Notes - Convertible Debt - USD ($)	Jun. 30, 2021	Dec. 31, 2020	Apr. 07, 2020
Related Party Transaction
Principal Amount	$ 35,868,000	$ 288,464,000
Director
Related Party Transaction
Principal Amount			$ 535,000,000

Uncategorized Items - w-2021063

Label	Element	Value
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]