Wayfair (W) 10-K 19 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 28, 2015
Entity Registrant Name	Wayfair Inc.
Entity Central Index Key	1616707
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float	$1,651
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2014
Class A common stock
Entity Common Stock, Shares Outstanding		37,199,841
Class B common stock
Entity Common Stock, Shares Outstanding		46,192,680

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets
Cash and cash equivalents	$355,859	$65,289
Short-term investments	60,000	50,019
Accounts receivable, net of allowance	5,949	7,689
Inventories	19,798	14,963
Prepaid expenses and other current assets	45,262	25,172
Total current assets	486,868	163,132
Property and equipment, net	60,639	22,088
Goodwill and intangible assets, net	6,478	9,084
Other noncurrent assets	1,538	2,001
Total assets	555,523	196,305
Current liabilities
Accounts payable	147,873	102,153
Accrued expenses	42,335	21,375
Deferred revenue	26,784	13,397
Other current liabilities	15,600	8,342
Total current liabilities	232,592	145,267
Other liabilities	17,392	1,030
Total liabilities	249,984	146,297
Stockholders' equity:
Additional paid-in capital	363,944
Accumulated deficit	-58,122	-190,850
Accumulated other comprehensive loss	-366	-328
Total stockholders' equity	305,539	-191,178
Total liabilities, and stockholders' equity	555,523	196,305
Class A common stock
Stockholders' equity:
Common stock	37
Class B common stock
Stockholders' equity:
Common stock	46
Series A convertible redeemable preferred units
Current liabilities
Convertible redeemable preferred units		$241,186

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Common units, par value (in dollars per unit)	$0	$0
Common units, shares authorized	0	74,328,124
Common units, shares issued	0	44,904,110
Common units, shares outstanding	0	44,904,110
Class A common stock
Common stock, par value (in dollars per unit)	$0.00	$0.00
Common stock, shares authorized	500,000,000	0
Common stock, shares issued	37,002,874	0
Common stock, shares outstanding	37,002,874	0
Class B common stock
Common stock, par value (in dollars per unit)	$0.00	$0.00
Common stock, shares authorized	164,000,000	0
Common stock, shares issued	46,179,192	0
Common stock, shares outstanding	46,179,192	0
Series A convertible redeemable preferred units
Convertible redeemable preferred units, par value (in dollars per unit)	$0	$0
Convertible redeemable preferred units, shares authorized	0	21,551,801
Convertible redeemable preferred units, shares issued	0	21,551,801
Series B convertible redeemable preferred units
Convertible redeemable preferred units, par value (in dollars per unit)	$0	$0
Convertible redeemable preferred units, shares authorized	0	0
Convertible redeemable preferred units, shares issued	0	0

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Operations
Net revenue	$1,318,951	$915,843	$601,028
Cost of goods sold (1)	1,007,853	691,602	455,879
Gross profit	311,098	224,241	145,149
Operating expenses:
Customer service and merchant fees (1)	55,804	35,500	25,730
Advertising	191,284	108,469	65,504
Merchandising marketing and sales	80,113	33,506	22,136
Operations, technology, general and administrative (1)	130,701	62,246	52,961
Amortization of acquired intangible assets	980	539	212
Total operating expenses	458,882	240,260	166,543
Loss from operations	-147,784	-16,019	-21,394
Interest income, net	350	245	234
Other (expense) income, net	-489	294	155
Total	-147,923	-15,480	-21,005
Provision for income taxes	-175	-46	-50
Net loss	-148,098	-15,526	-21,055
Accretion of convertible redeemable preferred units	-2,071	-25,388	-12,154
Net loss attributable to common stockholders	($150,169)	($40,914)	($33,209)
Net loss attributable to common Stockholders per share - basic and diluted	($2.97)	($0.99)	($0.80)
Weighted average number of common stock outstanding used in computing per share amounts - basic and diluted	50,641,601	41,331,546	41,271,992

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Comprehensive Loss
Net loss	($148,098)	($15,526)	($21,055)
Other comprehensive loss:
Foreign currency translation adjustments	-38	-390	-392
Comprehensive loss	($148,136)	($15,916)	($21,447)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Series A convertible redeemable preferred units	Series B convertible redeemable preferred units	Common Units.	Class A and Class B Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
In Thousands, except Share data, unless otherwise specified	USD ($)	USD ($)		USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
Balance at Dec. 31, 2011						($118,529)	$454	($118,075)
Balance at Dec. 31, 2011	167,480
Balance (in units) at Dec. 31, 2011			45,002,043
Balance (in units) at Dec. 31, 2011	17,666,664
Increase (Decrease) in Temporary Equity
Accretion of convertible redeemable preferred units	12,154
Issuance of convertible redeemable preferred units, net of issuance costs	36,164
Issuance of convertible redeemable preferred units, net of issuance costs (in units)	3,885,137
Increase (Decrease) in Stockholders' Equity
Net loss						-21,055		-21,055
Cumulative translation adjustment							-392	-392
Due to common unit holders						-154		-154
Paid-in capital						700		700
Accretion of convertible redeemable preferred units						-12,154		-12,154
Forfeiture of unvested units			-183,109
Balance at Dec. 31, 2012						-151,192	62	-151,130
Balance at Dec. 31, 2012	215,798
Balance (in units) at Dec. 31, 2012			44,818,934
Balance (in units) at Dec. 31, 2012	21,551,801
Increase (Decrease) in Temporary Equity
Accretion of convertible redeemable preferred units	25,388
Increase (Decrease) in Stockholders' Equity
Net loss						-15,526		-15,526
Cumulative translation adjustment							-390	-390
Accretion of convertible redeemable preferred units						-25,388		-25,388
Forfeiture of unvested units			-55,974
Return of equity held in escrow as part of acquisition						1,194		1,194
Return of equity held in escrow as part of acquisition (in units)			141,150
Equity compensation expense						62		62
Balance at Dec. 31, 2013						-190,850	-328	-191,178
Balance at Dec. 31, 2013	241,186
Balance (in units) at Dec. 31, 2013			44,904,110					44,904,110
Balance (in units) at Dec. 31, 2013	21,551,801
Increase (Decrease) in Temporary Equity
Accretion of convertible redeemable preferred units	14,417	2,455
Reduction of carrying value of convertible redeemable preferred stock	-14,801
Conversion of convertible redeemable preferred stock to common stock	-201,286	-157,229
Conversion of convertible redeemable preferred stock to common stock (in Units)	-21,551,801	-5,995,133
Issuance of convertible redeemable preferred units, net of issuance costs		154,774
Issuance of convertible redeemable preferred units, net of issuance costs (in units)		5,995,133
Dividends paid to convertible redeemable preferred unitholders	-39,516
Increase (Decrease) in Stockholders' Equity
Net loss						-148,098		-148,098
Cumulative translation adjustment							-38	-38
Accretion of convertible redeemable preferred units						-16,872		-16,872
Reduction of carrying value of convertible redeemable preferred stock						14,801		14,801
Conversion of convertible redeemable preferred stock to common stock				28	358,487			358,515
Conversion of convertible redeemable preferred stock to common stock (in shares)				27,546,934
Conversion from LLC to Corporation				44	-306,229	306,185
Conversion from LLC to Corporation (in shares)			-44,904,110	44,904,110
Issuance of Class A common stock - net of issuance costs				10	282,883			282,893
Issuance of Class A common stock - net of issuance costs (in shares)				10,500,000
Forfeiture of unvested units				-103,823
Repurchase of vested common units (in units)				-202,757
Exercise of options to purchase common stock					12			12
Exercise of options to purchase common stock (in shares)				157,453
Issuance of common stock upon vesting of RSUs				2				2
Issuance of common stock upon vesting of RSUs (in shares)				2,198,847
Shares withheld related to net settlement of RSUs				-1	-27,985			-27,986
Shares withheld related to net settlement of RSUs (in shares)				-918,100
Repurchase of common units						-23,500		-23,500
Repurchase of common units (in units)				-896,052
Return of equity held in escrow as part of acquisition						-49		-49
Return of equity held in escrow as part of acquisition (in units)				-4,546
Equity compensation expense					56,776	261		57,037
Balance at Dec. 31, 2014				$83	$363,944	($58,122)	($366)	$305,539
Balance (in shares) at Dec. 31, 2014				83,182,066
Balance (in units) at Dec. 31, 2014								0

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities
Net loss	($148,098)	($15,526)	($21,055)
Adjustments to reconcile net loss to net cash provided by operating activities, net of acquisition:
Depreciation and amortization	22,003	13,091	9,335
Equity based compensation	60,809
Other non-cash adjustments	570	121	110
Changes in operating assets and liabilities:
Accounts receivable and customer refunds payable	1,741	8,112	-8,234
Inventories	-4,835	-6,630	-2,497
Prepaid expenses and other current assets	-20,143	-9,159	-2,431
Accounts payable and accrued expenses	59,521	40,853	25,939
Deferred revenue and other liabilities	32,616	4,195	3,041
Other assets	-59	-644	-263
Net cash provided by operating activities	4,125	34,413	3,945
Cash flows from investing activities
Purchase of short-term investments	-135,000	-93,000	-66,065
Maturities of short-term investments	125,019	65,998	58,065
Purchase of property and equipment	-31,855	-6,739	-8,031
Site and software development costs	-14,130	-9,040	-6,949
Cash paid for acquisition		-3,741
Other investing activities, net	531	-469	-100
Net cash used in investing activities	-55,435	-46,991	-23,080
Cash flows from financing activities
Escrow proceeds from the issuance of Series A convertible redeemable preferred units in 2011			8,080
Proceeds from initial public offering, net of underwriter fees	282,893
Proceeds from exercise of stock options	12
Taxes paid related to net share settlement of equity awards	-27,985
Repurchase of common units	-23,500
Dividends paid to Series A convertible redeemable preferred	-39,516
Repurchase of employee equity	-5,528
Additional paid-in capital			700
Net cash provided by financing activities	341,150		44,944
Effect of exchange rate changes on cash and cash equivalents	730	6	25
Net decrease in cash and cash equivalents	290,570	-12,572	25,834
Cash and cash equivalents
Beginning of period	65,289	77,861	52,027
End of period	355,859	65,289	77,861
Supplemental disclosure of cash flow information
Income tax payments	37	3	17
Tax distribution receivable			154
Supplemental disclosure of non-cash investing activities
Issuance of common units in connection with acquisition		1,194
Purchase of property and equipment included in accounts payable and accrued expenses and in other liabilities	7,567
Construction costs capitalized under finance lease obligation	3,960
Supplemental disclosure of non-cash financing activities
Accretion of preferred unit dividends	2,071	25,388	12,154
Series A convertible redeemable preferred units
Cash flows from financing activities
Net proceeds from issuance of convertible redeemable preferred units			36,164
Series B convertible redeemable preferred units
Cash flows from financing activities
Net proceeds from issuance of convertible redeemable preferred units	$154,774

Basis_of_Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Basis Of Presentation
Basis of Presentation
	1. Basis of Presentation
	Wayfair Inc. is an e-commerce business offering visually inspiring browsing, compelling merchandising, easy product discovery and attractive prices for over seven million products from over 7,000 suppliers across distinct brands—Wayfair.com, Joss & Main, AllModern, DwellStudio, and Birch Lane. In addition to generating net revenue through Direct Retail sales, which includes all sales generated primarily through the Company's websites, mobile optimized websites, and mobile applications ("sites"), net revenue is also generated through sites operated by third parties and through third party advertising distribution providers that pay the Company based on the number of advertisement related clicks, actions, or impressions for advertisements placed on the Company's sites.
	The consolidated financial statements and other disclosures contained in this Annual Report on Form 10-K are those Wayfair Inc. Wayfair Inc. was incorporated as a Delaware corporation on August 8, 2014. Prior to the effectiveness of Wayfair Inc.'s registration statement on Form S-1 related to its initial public offering ("IPO") in October 2014, Wayfair LLC was the principal operating entity. In connection with the IPO of Wayfair Inc., Wayfair LLC completed an internal restructuring pursuant to which Wayfair LLC became a wholly-owned subsidiary of the Corporation, and the holders of equity interests in Wayfair LLC became stockholders of Wayfair Inc. The Company accounted for this restructuring in accordance with the guidance provided for entities under common ownership because the holders of the equity interests in Wayfair LLC held the same ownership interests in Wayfair Inc. as they did in Wayfair LLC immediately prior to the internal restructuring. SK Retail, Inc. was the only holder of equity interest in Wayfair LLC with operations. Accordingly the historical financial statements of SK Retail, Inc. have been combined with the historical financial statements of Wayfair LLC for the periods presented. As a result, accumulated deficit as of December 31, 2011 increased by $0.3 million and $1.9 million recorded as amounts due to related party as of December 31, 2013 has been reclassified to accrued expenses and no impact on the consolidated statements of operations since all costs had been included in the results of Wayfair LLC. In addition, all of our outstanding common units of Wayfair LLC were exchanged for, and all of our incentive units converted into, shares of Class B common stock. In addition, all of outstanding preferred units were exchanged for shares of Series A and Series B convertible preferred stock. Immediately prior to the completion of the IPO, all of our outstanding shares of Series A and Series B convertible preferred stock converted into shares of Class B common stock. In connection with this the Company also reclassified members' deficit of $306.2 million, accumulated under Wayfair LLC, to additional paid in capital.
	Prior period operating expense captions reported under sales and marketing in the consolidated statements of operations have been expanded to provide greater detail and to conform to current period presentation which includes customer service and merchant fees, advertising and merchandising, marketing and sales.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies
	2. Summary of Significant Accounting Policies
	Principles of Consolidation
	The accompanying consolidated financial statements of Wayfair Inc. include its wholly owned subsidiaries including the accounts of Wayfair LLC and its wholly owned subsidiaries (collectively the Company or Wayfair). All intercompany accounts and transactions have been eliminated. Below is a summary of the wholly-owned subsidiaries of the Company with operations:
	Subsidiary		Location
	Wayfair LLC		USA
	Wayfair Securities Corporation		USA
	SK Retail, Inc.		USA
	Wayfair Stores Limited		Republic of Ireland
	Wayfair (UK) Limited		United Kingdom
	Wayfair GmbH		Germany
	Wayfair (BVI) Ltd.		British Virgin Islands
	Wayfair Australia Pty Limited		Australia
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, at the date of the financial statements, and the reported amounts of revenue and expenses during the reported period. On an ongoing basis, management evaluates these estimates and judgments, including those related to revenue recognition, capitalization of site and software development costs, stock-based compensation, and inventory. Actual results could differ from those estimates.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with an original maturity (at the date of purchase) of three months or less to be the equivalent of cash for the purpose of consolidated balance sheets and statements of cash flows presentation. Cash equivalents, which consist primarily of money market accounts, are carried at cost, which approximates market value.
	Restricted Cash
	As of December 31, 2014 and 2013, there was $0.3 million, and $0.8 million, respectively, of cash that was restricted from withdrawal and held by banks to guarantee the Company's letters of credit issued principally to secure certain property leases.
	Short-Term Investments
	Short-term investments consist of certificates of deposits with original maturities of greater than three months and mature in less than twelve months.
	Accounts Receivable
	Accounts receivable are stated at the amount management expects to collect from outstanding balances. The Company estimates the allowance for doubtful accounts based on historical losses, existing economic conditions, and other information available at the consolidated balance sheets dates. Uncollectible amounts are written off against the allowance after all collection efforts have been exhausted.
	Fair Value of Financial Instruments
	The Company'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 the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. The Company measures its cash equivalents and short-term investments at fair value. The Company classifies its cash equivalents and short-term investments within Level 1 because the Company values these investments using quoted market prices. The fair value of the Company's Level 1 financial assets is based on quoted market prices of the identical underlying security. The Company does not have any assets or liabilities classified as Level 2 or Level 3 financial assets. See Note 3 for further details.
	Concentrations of Credit Risk
	Financial instruments that subject the Company to credit risk consist of cash and cash equivalents, short-term investments, and accounts receivable. The risk with respect to cash and cash equivalents and short-term investments is minimized by the Company's policy of investing in financial instruments (i.e., cash equivalents) with short-term maturities issued by highly rated financial institutions. At times, these balances may exceed federally insured limits; however, to date, the Company has not incurred any losses on these investments. As of December 31, 2014 and 2013, the Company had $2.1 million, and $2.6 million, respectively, in banks located outside the United States. The risk with respect to accounts receivable is managed by the Company through its policy of monitoring the creditworthiness of its customers to which it grants credit terms in the normal course of business.
	Leases
	The Company leases office space in several countries around the world under non-cancelable lease agreements. The Company generally leases its office facilities under operating lease agreements. Office facilities subject to an operating lease and the related lease payments are not recorded on the balance sheet. The terms of certain lease agreements provide for rental payments on a graduated basis, however, the Company recognizes rent expense on a straight-line basis over the lease period in accordance with authoritative accounting guidance. Any lease incentives are recognized as reductions of rental expense on a straight-line basis over the term of the lease. The lease term begins on the date the Company becomes legally obligated for the rent payments or when it takes possession of the office space, whichever is earlier.
	The Company establishes assets and liabilities for the estimated construction costs incurred under lease arrangements where the Company is considered the owner for accounting purposes only, or build-to-suit leases, to the extent the Company is involved in the construction of structural improvements or take construction risk prior to commencement of a lease. Upon occupancy of facilities under build-to-suit leases, the Company assesses whether these arrangements qualify for sales recognition under the sale-leaseback accounting guidance. If the Company continues to be the deemed owner, the facilities are accounted for as financing leases.
	Foreign Currency Translation
	The functional currency of the Company is the United States dollar, while the functional currency of certain wholly-owned subsidiaries outside of the United States is as follows:
	Subsidiary		Currency
	Wayfair Stores Limited		Euro
	Wayfair (UK) Limited		Pound sterling
	Wayfair GmbH		Euro
	Wayfair (BVI) Ltd.		Euro
	Wayfair Australia Pty Limited		Australian dollar
	The financial statements of the Company are translated to United States dollars using year-end exchange rates as to assets and liabilities and average exchange rates as to revenue and expenses. Capital accounts are translated at their historical exchange rates when the capital transaction occurred. The effects of foreign currency translation are included in other comprehensive loss in the consolidated statements of comprehensive loss. Transaction gains and losses are included in the Company's consolidated statements of operations. Translation adjustments arising from the use of differing exchange rates from period to period are included in accumulated other comprehensive loss within total stockholders' equity (deficit).
	Inventories
	Inventories consisting of finished goods are stated at the lower of cost or market, determined by the first-in, first-out (FIFO) method, and consist of product for resale. Inventory costs consist of cost of product and inbound shipping and handling costs. Inventory costs also include direct and indirect labor costs, rents and depreciation expenses associated with the Company's fulfillment centers. Inventory valuation requires the Company to make judgments, based on currently-available information, about the likely method of disposition, such as through sales to individual customers, liquidations, and expected recoverable values of each disposition category.
	Goods In-Transit
	Goods in-transit directly from suppliers to customers are recorded in prepaid expenses and other current assets. Risk of loss and the transfer of title from the supplier to the Company occur at freight on board shipping point. As of December 31, 2014 and 2013, goods in-transit amounted to $19.6 million, and $9.7 million, respectively.
	Property and Equipment
	Property and equipment are stated at cost, net of depreciation and amortization. Depreciation and amortization on property and equipment is calculated on the straight-line method over the estimated useful lives of the assets as follows:
	Class		Range of Life
			(In Years)
	Furniture and computer equipment		3 to 7
	Site and software development costs		2
	Leasehold improvements		The lesser of useful
			life or lease term
	Site and Software Development Costs
	The Company capitalizes costs associated with the development of its sites and internal-use software products after the preliminary project stage is complete and until the software is ready for its intended use. The capitalized costs are amortized over a two-year period. Costs incurred in the preliminary stages of development, after the software is ready for its intended use and for maintenance of internal-use software are expensed as incurred. Upgrade and enhancements are capitalized to the extent they will result in added functionality.
	Total costs capitalized, net of accumulated amortization, totaled $14.2 million, and $8.6 million as of December 31, 2014 and 2013, respectively, and are included in property and equipment, net in the accompanying consolidated balance sheets. Amortization expense for the years ended December 31, 2014, 2013 and 2012 were $9.9 million, $7.0 million, and $4.8 million, respectively. Capitalized software costs are included in property and equipment within our consolidated balance sheets.
	Goodwill
	Goodwill represents the excess of cost over the fair value of tangible and identifiable intangible assets acquired and liabilities assumed. Goodwill is not amortized, but is subject to an annual impairment test, or more frequently as impairment indicators arise.
	The Company tests goodwill for impairment at least annually. The Company reviews goodwill for impairment on the last day of its fiscal year and whenever events or changes in circumstances indicate that the carrying amount of this asset may exceed its fair value. The assessment is performed at the reporting unit level. The Company first assesses qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, an entity determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then the two-step impairment test is not required. If the qualitative assessment requires the Company to perform the two-step goodwill impairment test to identify potential goodwill impairment then the first step is to compare the fair value of the reporting unit to the book value including goodwill. If the fair value of the reporting unit exceeds the book value, goodwill is not impaired. If the book value exceeds the fair value, the second step of the process is performed to measure the amount of impairment.
	Long-Lived Assets
	The Company reviews long-lived assets for impairment whenever events or changes in circumstances, such as service discontinuance or technological obsolescence, indicate that the carrying amount of the long-lived asset may not be recoverable. When such events occur, the Company compares the carrying amount of the asset to the undiscounted expected future cash flows related to the asset. If the comparison indicates that an impairment exists, the amount of the impairment is calculated as the difference between the excess of the carrying amount over the fair value of the asset. If a readily determinable market price does not exist, fair value is estimated using discounted expected cash flows attributable to the asset. For the years ended December 31, 2014, 2013 and 2012, no impairment of long-lived assets or identifiable intangibles had been indicated.
	Revenue Recognition
The Company generates net revenue through product sales generated primarily through the sites of the Company's five distinct brands and through sites operated by third parties.
The Company recognizes revenue only when the following four criteria are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred; (3) the selling price is fixed or determinable; and (4) collectability is reasonably assured. The Company recognizes net revenue from sales of its products, upon delivery to the customer. The Company records product revenue at the gross amount as the Company is the primary obligor with the customer and provides the primary customer service for all products sold on its sites, has latitude in establishing price and selecting products sold on its sites, has discretion in selecting suppliers of products sold on its sites, maintains inventory risk from shipment through delivery date and upon accepting returns, and has credit risk. Net revenue includes shipping costs charged to the customer and is recorded net of taxes collected from customers, which are remitted to governmental authorities. Cash discounts, returns and rebates are deducted from gross revenue in determining net revenue. In addition, the Company defers revenue when cash is collected from its customer prior to the satisfaction of the revenue recognition criteria.
The Company maintains a membership rewards program that allows enrolled customers to earn points which can be redeemed for future purchases. The Company defers a portion of its revenue associated with rewards that are ultimately expected to be redeemed prior to expiration.
The Company also earns revenue through third-party advertisers that pay based on the number of advertisement related clicks, actions, or impressions for advertisements placed on the Company's sites. Revenue earned under these arrangements is included in net revenue and is recognized in the period in which the click, action, or impression occurs.
Vendor Rebates
The Company earns rebates under a volume incentive programs with its suppliers. These rebates are earned upon shipment of goods. Amounts earned and due from suppliers under these rebate programs are included in other current assets on the consolidated balance sheets and are reflected as a reduction of cost of goods sold on the consolidated statements of operations. Vendor allowances received by the Company reduce the carrying cost of inventory and are recognized in cost of goods sold when the related inventory is sold.
Costs of Goods Sold
Cost of goods sold consists of the cost of product sold to customers, shipping and handling costs and shipping supplies and fulfillment costs. Fulfillment costs include costs incurred in operating and staffing the fulfillment centers, such as costs attributed to receiving, inspecting, picking, packaging and preparing customer orders for shipment. Cost of goods sold also includes direct and indirect labor costs for fulfillment center oversight, including payroll and related benefit costs.
Advertising Costs
Expenditures for advertising are expensed in the period that the advertising first takes place. Advertising expense amounted to approximately $191.3 million, $108.5 million, and $65.5 million in the years ended December 31, 2014, 2013 and 2012, respectively. Included in prepaid expenses at December 31, 2014, 2013 and 2012, are approximately $0.6 million, $0.5 million, and $0.9 million, respectively, of prepaid advertising costs.
Merchant Processing Fees
Merchant processing fees totaling $27.6 million, $19.4 million, and $13.3 million in the years ended December 31, 2014, 2013 and 2012, respectively, are included in customer service and merchant fees expense in the accompanying consolidated statements of operations. These fees are charged by third parties that provide merchant processing services for credit cards and debit cards.
Retail Partner Fees
The Company sells its products through sites owned and operated by third-party online retailers, or retail partners. The Company pays a fee for sales generated through these sites and records them as merchant processing fees and advertising costs. Retail partner fees included in merchant processing fees are $4.4 million, $4.3 million, and $4.3 million for the years ended December 31, 2014, 2013 and 2012, respectively. Retail partner fees included in advertising costs are $24.3 million, $25.2 million, $22.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Equity-Based Compensation
The Company accounts for its equity-based compensation awards in accordance with ASC Topic 718, Compensation—Stock Compensation (ASC 718). ASC 718 requires all equity-based payments to employees, to be recognized as expense in the statements of operations based on their grant date fair values. The Company has granted stock options, restricted shares and restricted stock units.
The Company estimated the grant date fair value of each common stock option award using the Black-Scholes option-pricing model. The use of the Black-Scholes option-pricing model required management to make assumptions with respect to the expected term of the option, the expected volatility of the common stock consistent with the expected life of the option, risk-free interest rates and expected dividend yields of the common stock. Until its IPO in October 2014, the fair value of restricted stock and restricted stock units on the date of grant was determined by the board. Since April 2011, the Company has only granted restricted stock units and has not granted any stock options or restricted stock. Since our IPO restricted stock unit values are determined based on the quoted market price of our common stock on the date of grant.
Prior to the IPO the Company periodically determined for financial reporting purposes the estimated fair value of our common stock at various dates using contemporaneous valuations performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately Held Company Equity Securities Issued as Compensation, also known as the Practice Aid. The Company generally used the income and market approaches prescribed in the Practice Aid, in particular the income approach's discounted cash flow method, which was based on the Company's projections and estimated discount rate and the guideline public company, guideline transactions and precedent transaction methodologies, based on inputs from comparable public companies' equity valuations, comparable acquisition transactions and transactions in the Company's own equity securities, to estimate the enterprise value of the company. The Company performed these contemporaneous valuations as of December 31, 2011, June 30, 2012, December 31, 2012, June 30, 2013, September 30, 2013, December 31, 2013, March 31, 2014 and June 30, 2014.
In connection with the preparation of the financial statements for the year ended December 31, 2013, the Company undertook a retrospective reassessment of the fair market value of its common stock for certain of its 2013 grants for financial reporting purposes. As part of that reassessment, the Company determined that the grant date fair values of its May, August and November 2013 grants to be $6.46, $10.88 and $20.87, respectively. The fair value previously determined at various valuation dates increased substantially in 2013 and there was no particular transaction or event that caused this increase. The grants made in May, August and November 2013 were between the dates when the Company performed its valuation. Accordingly, the Company calculated grant date fair value for these grants on a linear basis between each valuation date and believe it to be a reasonable method. Similarly in connection with the preparation of the financial statements for the quarter ended September 30, 2014, the Company undertook a retrospective reassessment of the fair market value of our common stock for our grants made in September 2014 to be equal to our October 2, 2014 IPO price of $29.00.
Income Taxes
Income taxes are accounted for under the asset and liability method. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases.
Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The Company records valuation allowances to reduce deferred income tax assets to the amount that is more likely than not to be realized. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, no amount of benefit attributable to the position is recognized. The tax benefit to be recognized of any tax position that meets the more likely than not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency.
Prior to the IPO, the Company's main operating entity had not been subject to U.S. federal income taxes as it was organized as a limited liability company. As such, the taxable income or loss was passed through to and included in the tax returns of the members. The Company was subject to entity level taxation in certain states, and certain domestic and foreign subsidiaries were subject to entity level U.S. and foreign income taxes. As a result of the internal restructuring prior to the IPO, a portion of the Company's income will be subject to U.S. federal, state, local, and foreign income taxes and taxed at the prevailing corporate tax rates.
Net Loss Attributable to Common Stockholders Per Share
The Company follows the two-class method when computing net loss attributable to common stockholders per share as the Company had issued shares that meet the definition of participating securities which converted to common stock upon the IPO. Prior to the internal restructuring, the Company's convertible redeemable preferred units contractually entitled the holders of such units to participate in dividends, but did not contractually require the holders of such units to participate in losses of the Company. Accordingly, in periods prior to 2014 in which the Company reports a net loss or a net loss attributable to common shareholders resulting from preferred stock dividends or accretion, net losses are not allocated to participating securities. After the IPO the Company has continued to follow the two-class method because it has issued two classes of common stock—Class A and Class B.
Basic net income (loss) attributable to common stockholders per share is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of common stock outstanding for the period. For periods in which the Company has reported net losses, diluted net loss per share attributable to common shareholders is the same as basic net loss per share attributable to common stockholders, since dilutive common stock are not assumed to have been issued if their effect is anti-dilutive.
Subsequent Events
The Company considers events or transactions that have occurred after the balance sheet date of December 31, 2014, but prior to the filing of the financial statements with the Securities and Exchange Commission to provide additional evidence relative to certain estimates or to identify matters that require additional recognition or disclosure. Subsequent events have been evaluated through the filing of these financial statements.
Recent Accounting Pronouncements
In July 2013, the Financial Accounting Standards Board ("FASB") issued a new accounting standard update that requires the presentation of certain unrecognized tax benefits as reductions to deferred tax assets rather than as liabilities in the consolidated balance sheets when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The Company adopted this new standard on a prospective basis in the first quarter of fiscal 2014, and the adoption of this accounting standard update did not have a material impact on the Company's consolidated financial statements.
In May 2014, the FASB issued new accounting guidance regarding revenue recognition under GAAP. This new guidance will supersede nearly all existing revenue recognition guidance, and is effective for public entities for annual and interim periods beginning after December 31, 2016. Early adoption is not permitted. The Company is currently evaluating the impact of this new guidance on the Company's consolidated financial statements.
In August 2014, the FASB issued Accounting Standards Update No. 2014-15, "Presentation of Financial Statements—Going Concern", which requires management to evaluate, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. ASU 2014-15 is effective for annual periods ending after December 15, 2016 and interim periods thereafter. Early application is permitted. The adoption of ASU 2014-15 is not expected to have a material effect on the consolidated financial statements.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements
Fair Value Measurements	3. Fair Value Measurements
	The following tables set forth the fair value of the Company's financial assets measured at fair value on a recurring basis as of December 31, 2013 and 2014 based on the three-tier value hierarchy:
		December 31, 2014
		Total		Level 1		Level 2		Level 3
		(in thousands)
	Cash equivalents
	Money market funds	$	302,595	$	302,595		—		—
	Short-term investments:
	Certificates of deposit		60,000		60,000		—		—
	Restricted cash
	Money market funds		302		302		—		—
	Total	$	362,897	$	362,897	$	—	$	—
		December 31, 2013
		Total		Level 1		Level 2		Level 3
		(in thousands)
	Cash equivalents
	Money market funds	$	32,560	$	32,560		—		—
	Short-term investments:
	Certificates of deposit		50,019		50,019		—		—
	Restricted cash
	Money market funds		346		346		—		—
	Total	$	82,925	$	82,925	$	—	$	—
	Assets Measured and Recorded at Fair Value on a Nonrecurring Basis
	The Company remeasures the fair value of certain assets upon the occurrence of certain events. In 2014, the Company recorded goodwill impairment charges of $0.8 million after remeasuring the fair value of the goodwill associated with its Australian reporting unit. This adjustment falls within Level 3 of the fair value hierarchy due to the use of significant unobservable inputs to determine fair value. The fair value measurements were determined using the income and the market approaches. The income approach uses a discounted cash flow analysis. The market approach includes the guideline public company method and guideline transaction method.

Intangible_assets_and_Goodwill

Intangible assets and Goodwill	12 Months Ended
	Dec. 31, 2014
Intangible assets and Goodwill
Intangible assets and Goodwill	4. Intangible assets and Goodwill
	Intangible assets consisted of the following as of December 31, 2013 and 2014 (in thousands):
		Weighted-		December 31, 2014							December 31, 2013
		Average
		Amortization
		Period
		(Years)		Gross		Accumulated			Net Book		Gross		Accumulated			Net Book
				Carrying		Amortization			Value		Carrying		Amortization			Value
				Value							Value
	Trademarks	5		$	2,001	$	(604	)	$	1,397	$	2,030	$	(219	)	$	1,811
	Customer relationships	5			1,300		(368	)		932		1,300		(108	)		1,192
	Non-compete agreements	3 - 5			108		(52	)		56		110		(19	)		91
	Technology	5			718		(467	)		251		920		(430	)		490
	Other intangibles	3			373		(158	)		215		373		(47	)		326
	Domain names	5			2,687		(2,684	)		3		2,695		(2,686	)		9
	Total			$	7,187	$	(4,333	)	$	2,854	$	7,428	$	(3,509	)	$	3,919
	The following is a summary of the estimated aggregate amortization expense in future years at December 31, 2014 (in thousands):
	2015	$	961
	2016		880
	2017		640
	2018 and thereafter		373
		$	2,854
	For the years ended December 31, 2013 and 2012, no impairment of goodwill had been indicated. At the end of 2014, because the Company identified material reductions in revenue expectations and increased costs for its Australian reporting unit, it performed a qualitative assessment which required it to perform the two step test. Step one indicated that the fair value of the reporting unit was below the book value including goodwill. Upon completion of its second step the Company identified and recorded a goodwill impairment of $0.8 million which is included in the consolidated statements of operations under operations, technology, general and administrative. The remaining goodwill in that reporting unit is approximately $1.7 million and will continue to be evaluated on a quarterly basis. In 2014 goodwill was reduced by $0.7 million as a result of foreign exchange fluctuations in addition to the reduction due to the impairment.

Property_and_Equipment_net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2014
Property and Equipment, net
Property and Equipment, net	5. Property and Equipment, net
	Property and equipment, net consists of the following:
		December 31,
		2014			2013
		(in thousands)
	Furniture and computer equipment	$	48,399		$	26,218
	Site and software development costs		36,294			23,715
	Leasehold improvements		14,290			1,912
	Construction in progress		4,800			184
			103,783			52,029
	Less accumulated depreciation and amortization		(43,144	)		(29,941	)
	Property and equipment, net	$	60,639		$	22,088
	Property and equipment depreciation and amortization expense was $20.8 million, $12.5 million, and $8.6 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Accrued_Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2014
Accrued Expenses
Accrued Expenses	6. Accrued Expenses
	Accrued expenses consist of the following:
		December 31,
		2014		2013
		(in thousands)
	Employee compensation and related benefits	$	15,244	$	9,517
	Marketing		9,561		5,329
	Accrued property, plant and equipment		7,151		—
	Credit card		3,560		2,213
	Audit, legal and professional fees		898		377
	Other accrued expenses		5,921		3,939
		$	42,335	$	21,375

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Commitments and Contingencies	7. Commitments and Contingencies
	Leases
	The Company leases office space under non-cancelable leases. These leases expire at various dates through 2024 and include discounted rental periods and fixed escalation clauses, which are amortized straight-line over the terms of the lease. Rental expense under operating leases was $11.4 million, $4.6 million, and $3.0 million in the years ended December 31, 2014, 2013 and 2012, respectively. The Company has issued letters of credit for approximately $3.3 million as security for these lease agreements.
	Future lease payments under non-cancelable leases are as follows as of December 31, 2014:
		Amount
		(in thousands)
	2015	$	13,303
	2016		15,596
	2017		15,245
	2018		15,337
	2019		13,970
	Thereafter		53,936
		$	127,387
	Future lease payments have not been reduced by minimum sublease rentals of $1.1 million due to the Company in the future under non-cancelable subleases.
	In March 2014, the Company expanded the lease of office space in Boston, MA to a total of approximately 275,000 square feet through 2024. The Company has an option to extend the lease for two successive 5 year periods.
	In September 2014, the Company signed a lease to expand its warehouse space in Ogden, UT by an additional 180,000 square feet through 2022 which it plans to occupy in 2015. The Company established a long-term asset and liability of $3.9 million for the estimated construction costs incurred under this lease arrangement through December 31, 2014 since the Company is considered the owner for accounting purposes only during the construction period. Upon occupancy of the facility, which is expected in 2015, the Company will assess whether this arrangement qualifies for sales recognition under the sale-leaseback accounting guidance. If the Company continues to be the deemed owner, the facility will be accounted for as a financing lease.
	Collection of Sales or Other Similar Taxes
	Based on the location of the Company's current operations, it collects and remits sales tax in Kentucky, Massachusetts, New York and Utah. The Company does not currently collect sales or other similar taxes for the sale of goods in states where no obligation to collect these taxes is required under applicable law. Several states have presented the Company with assessments, alleging that it is required to collect and remit sales or other similar taxes. The aggregate amount of claims from these states is approximately $11.7 million. The Company does not believe that it was obligated to collect and remit such taxes, and intends to vigorously defend its position. At this time, the Company believes a loss is not probable hence a liability has not been recorded, however, no assurance can be given as to the outcome of this situation.
	Legal Matters
	The Company is subject to legal proceedings and claims in the ordinary course of business. However, the Company is not currently aware of any legal proceedings or claims that it believes will have, individually or in the aggregate, a material adverse effect on the Company's financial position, results of operations or cash flows.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Employee Benefit Plans
Employee Benefit Plans	8. Employee Benefit Plans
	The Company has a defined-contribution, incentive savings plan pursuant to Section 401(k) of the Internal Revenue Code. The plan covers all full-time employees who have reached the age of 21 years. Employees may elect to defer compensation up to a dollar limit (as allowable by the Internal Revenue Code), of which up to 4% of an employee's salary will be matched by the Company. The amounts deferred by the employee and the matching amounts contributed by the Company both vest immediately. The amount expensed under the plan totaled approximately $2.4 million, $1.8 million, and $1.5 million in the years ended December 31, 2014, 2013 and 2012, respectively.

EquityBased_Compensation

Equity-Based Compensation	12 Months Ended
	Dec. 31, 2014
Equity-Based Compensation
Equity-Based Compensation	9. Equity-Based Compensation
	In 2010 the Company established an equity incentive plan and in 2011, the plan was amended and restated as the Wayfair LLC Amended and Restated 2010 Common Unit Plan (the "2010 Plan"). The 2010 Plan was administered by the board of directors of Wayfair LLC and provided for the issuance of common option units, deferred units, and restricted common units (all common units), which currently represent Class B common stock of the Company.
	In connection with the IPO of Wayfair Inc. as described earlier, Wayfair LLC completed an internal restructuring pursuant to which Wayfair LLC became a wholly-owned subsidiary of Wayfair Inc., and the holders of equity interests in Wayfair LLC became stockholders of Wayfair Inc. In addition, all of the outstanding common units and incentive units of Wayfair LLC were exchanged for shares of common stock or incentive units for common stock, and then were converted into shares of Class B common stock or incentive units for Class B common stock of Wayfair Inc. Accordingly, common option units, restricted common units and deferred units were converted to stock options, restricted common stock and restricted common units ("RSU"), respectively, and may be referred to as such in these notes to the consolidated financial statements. In connection with the IPO, the board of directors of Wayfair Inc. took over administration of the 2010 Plan and adopted the 2014 Incentive Award Plan ("2014 Plan") to grant cash and equity incentive awards to eligible service providers in order to attract, motivate and retain the talent for which the Company competes. The 2014 Plan is administered by the board of directors of Wayfair Inc. with respect to awards to non-employee directors and by the compensation committee with respect to other participants and provides for the issuance of stock options, SARs, restricted stock, RSUs, performance shares, stock payments, cash payments, dividend awards and other incentives. The 2014 Plan authorizes up to 8,603,066 shares of Class A common stock Wayfair Inc. to be issued, of which no shares had been issued as of December 31, 2014. Shares or RSUs forfeited and unexercised stock option lapses from the 2010 Plan are available for grants of awards under the 2014 Plan. Any future grants of awards are expected to vest over the service period, typically five years.
	All equity awards granted prior to the IPO were subject to two vesting triggers: a service period (typically five years) and a performance condition (a liquidity event in the form of either a change of control or an initial public offering, each as defined in the Amended Plan). Employees were able to retain provisionally vested stock options and shares upon departure. The Company determined that a liquidity event was not probable until the closing of its IPO on October 7, 2014, and as such, no expense was recognized until that date. After the IPO awards for employees still providing service will continue to vest over the remaining service period. In the fourth quarter of 2014 the Company recorded $55.3 million of equity based compensation calculated under the accelerated attribution method and the service period for the majority of this expense was satisfied prior to the IPO. In addition the Company recorded an asset of $1.4 million as site and software development cost. The Company will continue to record equity based compensation expense in future periods.
	In April 2014, the Company completed a tender offer to repurchase provisionally vested (defined as service period completed) stock options and restricted common stock from certain employees at a price of $26.23 per share. A total of 202,757 shares of restricted common stock and 9,028 stock options were tendered for an aggregate of approximately $5.5 million in net cash after adjusting for the exercise prices associated with the stock options. This tender offer was accounted for as a modification resulting in a $5.5 million compensation charge when accepted by the employee. The Company recorded an expense of $5.5 million in the year ended December 31, 2014.
	A summary of the status and activity for awards of stock options for the year ended December 31, 2013 and 2014 is as follows:
		Stock			Weighted-Average		Weighted-Average
		Options			Exericse Price		Remaining
							Contractual Term
							(Years)
	Outstanding at December 31, 2013		664,232		$	2.99		6.7
	Exercised		(177,704	)	$	2.99
	Repurchased		(9,028	)	$	2.93
	Forfeited/cancelled		(28,454	)	$	3.11
	Outstanding at December 31, 2014		449,046		$	2.98		6.5
	Exercisable at December 31, 2014		409,567		$	2.96		6.5
	Expected to vest as of December 31, 2014		26,277		$	3.1		6.5
	Intrinsic value of stock options exercised and repurchased was $4.3 million for the year ended December 31, 2014. Aggregate intrinsic value of stock options outstanding and currently exercisable is $7.6 million and $6.9 million respectively. Unrecognized equity based compensation expense related to stock options expected to vest is less than $0.1 million with a weighted average remaining vesting term of 0.3 years as of December 31, 2014.
	A summary of the status and activity for awards of restricted common stock for the years ended December 31, 2014 and 2013 is as follows:
		Restricted			Weighted-Average
		Stock			Grant Date
					Fair Value
	Unvested at December 31, 2013		3,490,968		$	4.75
	Vested		(3,022,912	)	$	4.75
	Repurchased		(202,757	)	$	4.75
	Forfeited/cancelled		(103,823	)	$	4.75
	Unvested at December 31, 2014		161,476		$	4.75
	Expected to vest as of December 31, 2014		109,150		$	4.75
	The intrinsic value of restricted common stock vested and repurchased was $101.5 million for the year ended December 31, 2014. Aggregate intrinsic value of restricted common stock outstanding is $3.2 million as of December 31, 2014. Unrecognized equity based compensation expense related to restricted common stock expected to vest is less than $0.1 million with a weighted average remaining vesting term of 0.2 years as of December 31, 2014.
	A summary of the status and activity for awards of RSUs for the year ended December 31, 2014 and 2013 is as follows:
		Restricted			Weighted-Average		Weighted-Average
		Stock Units			Grant Date		Remaining
					Fair Value		Contractual Term
							(Years)
	Unvested at December 31, 2013		5,255,113		$	7.95		6
	Granted		1,953,227		$	27.07
	Vested		(2,198,857	)	$	7.89
	Forfeited/cancelled		(467,252	)	$	12.31
	Unvested at December 31, 2014		4,542,231		$	17.67		5.6
	Expected to vest as of December 31, 2014		3,394,145		$	18.11		5.7
	The intrinsic value of RSU vested was $69.0 million for the year ended December 31, 2014. Aggregate intrinsic value of RSUs outstanding is $90.2 million as of December 31, 2014. Unrecognized equity based compensation expense related to RSUs expected to vest is $38.2 million with a weighted average remaining vesting term of 1.7 years as of December 31, 2014.

Stockholders_Equity_Deficit

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity (Deficit)
Stockholders' Equity (Deficit)	10. Stockholders' Equity (Deficit)
	Corporate Reorganization
	On October 1, 2014, in anticipation of the IPO, the Company completed an internal restructuring as described in note 1. Pursuant to the restructuring, Wayfair LLC became a wholly-owned subsidiary of Wayfair Inc., and the holders of equity interests in Wayfair LLC became stockholders of Wayfair Inc. Wayfair Inc. was incorporated as a Delaware corporation on August 8, 2014. In connection with this restructuring $306.2 million of accumulated deficit from Wayfair LLC was transferred to additional paid in capital of Wayfair Inc.
	Series A and Series B Convertible Redeemable Preferred Units of Wayfair LLC
	In connection with the internal restructuring all of the outstanding Series A and Series B Preferred Units were exchanged for shares of Series A and Series B convertible preferred stock. Immediately prior to the completion of the IPO, all of the outstanding shares of Series A and Series B convertible preferred stock converted into 27,546,934 shares of Class B common stock of Wayfair Inc.
	The Company recognized changes in the redemption value of the convertible redeemable preferred stock immediately as they occurred by adjusting the carrying amount of the redeemable security to what would be the redemption amount assuming the security was redeemable at the balance sheet date. Accordingly, the Company recorded accretion of the Series A stock of $14.4 million credit, $25.4 million, and $12.2 million for the years ended December 31, 2014 and 2013 and 2012, respectively. At the time of the conversion of Series A and Series B convertible preferred stock an adjustment of $14.8 million was recorded as a reduction of accretion expense when the carrying value of the convertible redeemable preferred units was reduced to its conversion value. The Company recorded accretion on the Series B stock of $2.5 million for the year ended December 31, 2014.
	Upon the issuance of Series B units in March 2014, the Company distributed $15.0 million in accrued dividends to Series A holders and upon the completion of the IPO in October 2014 distributed the remaining accrued dividends of $24.5 million to Series A holders.
	Common Units of Wayfair LLC
	Upon the internal restructuring, and in connection with the IPO, all of the outstanding common units were exchanged for shares of common stock and further reclassified into 44,904,110 shares of Class B common stock of Wayfair Inc. As of December 31, 2014, Wayfair Inc. had 83,182,066 shares of Class A and Class B common stock outstanding.
	Preferred Stock
	Upon the closing of the IPO in October 2014, Wayfair Inc. authorized 10,000,000 shares of undesignated preferred stock, $0.001 par value per share, for future issuance. As of December 31, 2014, Wayfair Inc. had no shares of undesignated preferred stock issued or outstanding.
	Common Stock
	On October 7, 2014, the Company completed its IPO of 12,650,000 shares of its Class A common stock at a public offering price of $29.00 per share, of which 10,500,000 shares were sold by the Company and 2,150,000 shares were sold by its selling stockholders, including 1,650,000 shares pursuant to the underwriters' option to purchase additional shares, resulting in net proceeds to the Company of approximately $282.9 million, after deducting underwriting discounts and offering expenses. The Company did not receive any proceeds from the sale of shares by the selling stockholders.
	The Company 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 37,002,874 shares of Class A common stock and 46,179,192 shares of Class B common stock were outstanding as of December 31, 2014. The rights of the holders of Class A common stock and Class B common stock are identical, except with respect to voting and conversion rights. Each share of Class A common stock is entitled to one vote per share. Each share of Class B common stock is entitled to ten votes per share and is convertible into one share of Class A common stock. 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 662/3% 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, in its discretion, determines to issue dividends and then only at the times and in the amounts that the Board may determine. Since the IPO 24,352,874 shares of Class B common stock were converted to Class A common stock through December 31, 2014.

Segment_and_Geographic_Informa

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2014
Segment and Geographic Information
Segment and Geographic Information	11. Segment and Geographic Information
	The Company considers operating segments to be components of the Company in which separate financial information is available that is evaluated regularly by our chief operating decision maker ("CODM") in managing and accessing the business. The CODM for the Company is the Chief Executive Officer. The CODM reviews financial information presented on a consolidated basis for purposes of making operating decisions, allocating resources and evaluating financial performance. Accordingly, the Company has determined that it has one operating and reportable segment. No country outside of the United States provided greater than 10% of total revenue.
	The Company generates net revenue from Direct Retail sales derived through the Company's sites and Other sales derived through sites operated by third parties and fees from third-party advertising distribution providers as set forth below:
		Year Ended December 31,
		2014		2013		2012
		(in thousands)
	Net revenue
	Direct Retail	$	1,101,686	$	673,446	$	389,290
	Other		217,265		242,397		211,738
	Net revenue	$	1,318,951	$	915,843	$	601,028
	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 table sets forth revenue and long-lived assets by geographic area:
		Year Ended December 31,
		2014		2013		2012
		(in thousands)
	Geographic net revenue:
	United States	$	1,236,215	$	857,001	$	542,736
	International		82,736		58,842		58,292
	Total	$	1,318,951	$	915,843	$	601,028
		Year Ended
		December 31,
		2014		2013
		(in thousands)
	Geographic long-lived assets:
	United States	$	59,013	$	21,451
	International		1,626		637
	Total	$	60,639	$	22,088

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes	12. Income Taxes
	Income tax expense (benefit) for the years ended December 31, 2014, 2013 and 2012 attributable to income (loss) from operation is presented below (in thousands):
	Year ended December 31, 2014	Current			Deferred			Total
	Federal	$	—		$	32		$	32
	State		1			4			5
	Foreign		138			—			138
		$	139		$	36		$	175
	Year ended December 31, 2013	Current			Deferred			Total
	Federal	$	—		$	—		$	—
	State		1			—			1
	Foreign		41			4			45
		$	42		$	4		$	46
	Year ended December 31, 2012	Current			Deferred			Total
	Federal	$	—		$	—		$	—
	State		—			—			—
	Foreign		50			—			50
			50			—			50
	The actual income tax expense (benefit) differs from the expected income tax expense (benefit) computed by applying the United States Federal corporate income tax rate of 35% to income before tax expense (benefit) as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Computed expected tax expense (benefit)	$	(51,773	)	$	(5,417	)	$	(7,352	)
	Decrease in income taxes resulting from:		—			—			—
	Partnership losses not creating tax benefit		21,369			3,920			4,620
	Effect of conversion to C-corporation		(28,034	)		—			—
	State income tax expense, net of federal benefit		(2,517	)		(269	)		—
	Foreign tax rate differential		2,826			619			1,500
	Restricted stock expense		5,555			—			—
	Change in valuation allowance		52,921			1,418			1,199
	Other		(172	)		(225	)		83
	Net income tax expense (benefit)	$	175		$	46		$	50
	The components of results of income before income tax expense (benefit) determined by tax jurisdiction, are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	United States	$	(128,505	)	$	(9,895	)	$	(13,299	)
	Foreign		(19,418	)		(5,585	)		(7,706	)
	Total	$	(147,923	)	$	(15,480	)	$	(21,005	)
	The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities for the periods presented are as follows (in thousands):
		December 31
		2014			2013
	Deferred tax asset:
	Accounts receivable, due to allowance for doubtful accounts	$	1,009		$	—
	Inventories		295			—
	Operating loss carry-forwards		17,939			6,901
	Stock-based compensation expense		11,529			—
	Intangibles due to differences in amortization		26,557			—
	Accrued Expenses/Other		3,555			1
	Charitable Contributions		18			—
	Deferred Rent		7,161			—
	Gross deferred tax asset		68,063			6,902
	Less: Valuation allowance		(58,980	)		(6,902	)
	Net deferred tax asset		9,083			—
	Deferred tax liability:
	Prepaid expenses		(783	)		—
	Capitalized technology		(5,019	)		—
	Property and equipment, due to difference in depreciation		(3,281	)		—
	Tax-deductible goodwill		(36	)		—
	Total deferred tax liabilities		(9,119	)		—
	Net deferred tax assets		(36	)
	Current net deferred tax asset		(55	)		—
	Current net deferred tax liability		—			—
	Non-current net deferred tax asset		19			—
	Non-current net deferred tax liability		—			—
			(36	)		—
	As of December 31, 2014, the Company had federal net operating loss carryforwards available to offset future federal taxable income of $84.9 million. Approximately $60.2 million of the federal net operating loss carryforward will result in an increase to additional paid-in capital if and when these carryforwards are used to reduce income taxes payable.
In addition, the Company had state net operating loss carryforwards available in the amount of $81.2 million which are available to offset future state taxable income. Approximately $57.5 million of the state net operating loss carryforward will result in an increase to additional paid-in capital if and when these carryforwards are used to reduce income taxes payable.
The federal net operating loss carryforwards begin to expire in the year ended December 31, 2034. The state net operating loss carryforwards begin to expire in the year ended December 31, 2029.
The Company's ability to utilize these federal and state net operating loss carry-forwards may be limited in the future if the Company experiences an ownership change pursuant to Internal Revenue Code Section 382. An ownership change occurs when the ownership percentages of 5% or greater stockholders change by more than 50% over a three-year period.
The Company also had foreign net operating loss carry-forwards available to offset future foreign income of $46.9 million. The foreign net operating loss carryforwards have no expiration.
In assessing the realizability of its net deferred tax assets, the Company considered whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets depends upon the generation of future taxable income during the periods in which those temporary differences become deductible. As of December 31, 2014, based upon an evaluation of the positive and negative evidence, the Company concluded that an increase of $52.1 million of the deferred tax asset valuation allowance was appropriate, resulting in a valuation allowance of $ 59.0 million as of December 31, 2014. The total expense from the change in valuation allowance is $52.9 million.
As of December 31, 2014, the Company has not provided for U.S. deferred income taxes on undistributed earnings of its foreign subsidiaries of approximately $0.9 million since these earnings are to be indefinitely reinvested. Upon distribution of those earnings in the form of dividends or otherwise, the Company will be subject to additional U.S. and state income taxes (less foreign tax credits), as well as withholding taxes in its foreign locations. The amount of taxes attributable to the undistributed earnings is not practicably determinable.
The Company establishes reserves for uncertain tax positions based on management's assessment of exposure associated with tax deductions, permanent tax differences and tax credits. The tax reserves are analyzed periodically and adjustments are made as events occur to warrant adjustment to the reserve. The Company's policy is to recognize interest and penalties related to unrecognized tax benefits as a component of income tax expense.
The Company had gross unrecognized tax benefits of $0.2 million as of December 31, 2014 and 2013. At December 31, 2014, $0.2 million represents the amount of unrecognized tax benefits that, if recognized, would result in a reduction of the Company's effective tax rate. During the years ended December 31, 2014, 2013 and 2012 the total gross amount of unrecognized tax benefits remain unchanged.
The Company recognizes interest accrued related to unrecognized tax benefits and penalties as income tax expense. Related to the unrecognized tax benefits noted above, the Company did not accrue any penalties and interest during the years ended December 31, 2014, 2013 and 2012 because it believes that such additional interest and penalties would be insignificant. As of December 31, 2014, the combined amount of accrued interest and penalties related to tax positions taken on our tax returns and included in non-current income taxes payable was less than $0.1 million.
The Company believes that it is reasonably possible that its remaining unrecognized tax benefits may be recognized by the end of 2015 as a result of a lapse of the statute of limitations.
The Company's tax jurisdictions include the United States, the UK, Germany, Ireland, Australia, and the British Virgin Islands. The statute of limitations with respect to the Company's United States federal income taxes has expired for years prior to 2011, except for the 2008 tax year for one of the Company's corporate subsidiaries. The relevant state and foreign statutes vary. However, preceding years remain open to examination by United States federal and state and foreign taxing authorities to the extent of future utilization of net operating losses generated in each preceding year.

Credit_Agreement

Credit Agreement	12 Months Ended
	Dec. 31, 2014
Credit Agreement
Credit Agreement	13. Credit Agreement
	The Company has a credit agreement with Bank of America, which provides the Company with a line of credit for up to $25.0 million, with the committed amounts of $10.0 million to be used for a revolving line of credit and to support letters of credit and $15.0 million to be used to support the Company's credit card program. The Company is required to maintain certain covenants, including debt service coverage, tangible net worth, and unencumbered liquid assets. The Company did not borrow any amounts under the credit agreement during the years ended December 31, 2014, 2013 and 2012. The credit agreement is renewable on an annual basis. The Company renewed this agreement on June 6, 2014 and it will mature on July 31, 2015.

RelatedParty_Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2014
Related-Party Transactions
Related-Party Transactions	14. Related-Party Transactions
	The Company has done business with a company owned by a family member of one of the Company's officers. During the year ended December 31, 2012, the Company paid this related party $2,000 as part of a revenue-sharing agreement. In addition, the Company paid this related party and its affiliates $200, $4,000, and $21,000 in the years ended December 31, 2014, 2013 and 2012, respectively, in conjunction with a supplier relationship.

Net_Loss_per_Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2014
Net Loss per Share
Net Loss per Share	15. Net Loss per Share
	Basic and diluted net (loss) income per share is presented using the two class method required for participating securities. Class A and Class B common stock are the only outstanding equity in the Company since our IPO in October 2014. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. 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. The Class B common stock also has approval rights over certain corporate actions. Each share of Class B common stock may be converted into one share of Class A common stock at any time at the option of the stockholder, and will be automatically converted into one share of Class A common stock upon a sale or transfer, subject to certain limited 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 at least 662/3% of the outstanding shares of Class B common stock, all outstanding shares of Class B common stock will automatically convert into Class A common stock.
	Basic net income (loss) per share attributable to common stockholders is computed using the weighted-average number of shares of common stock outstanding during the period. Diluted net income (loss) per share attributable to common stockholders is computed using the weighted-average number of shares of common stock and, if dilutive, common stock equivalents outstanding during the period. The Company's common stock equivalents consist of shares issuable upon the release of restricted stock units, and to a lesser extent, the incremental shares of common stock issuable upon the exercise of stock options and unvested restricted stock. The dilutive effect of these common stock equivalents is reflected in diluted earnings per share by application of the treasury stock method. The Company's basic and diluted net loss per share are the same because the Company has generated net loss to common stockholders and common stock equivalents are excluded from diluted net loss per share because they have an antidilutive impact.
	The Company allocates undistributed earnings between the classes on a one-to-one basis when computing net income (loss) per share. As a result, basic and diluted net income (loss) per Class A and Class B shares are equivalent.
	Even prior to the conversion of its Series A and Series B convertible preferred stock to common stock, effective October 7, 2014, the Company applied the two class method for calculating and presenting earnings per share. Under the two class method, net (loss) income attributable to common stockholders is determined by allocating undistributed earnings between common stock and participating securities. Undistributed earnings are calculated as net income (loss) less distributed earnings and accretion of Series A and Series B convertible preferred stock. As holders of Series A and Series B convertible preferred stock did not have a contractual obligation to share in the losses of the Company, the net loss attributable to common stockholders for each periods prior to the IPO was not allocated between common stock and participating securities. Accordingly, Series A and Series B convertible preferred stock are excluded from the calculation of basic and diluted net loss per share. The Company's basic and diluted net loss per share are the same because the Company has generated net loss to common stockholders and common stock equivalents are excluded from diluted net loss per share because they have an antidilutive impact.
	The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data):
		Year Ended December 31,
		2014			2013			2012
	Numerator:
	Net loss	$	(148,098	)	$	(15,526	)	$	(21,055	)
	Accretion of preferred units to redemption value	$	(2,071	)	$	(25,388	)	$	(12,154	)
	Net loss attributable to common stockholders per share—basic and diluted	$	(150,169	)	$	(40,914	)	$	(33,209	)
	Denominator:
	Weighted average shares used for basic and diluted net loss per share computation		50,641,601			41,331,546			41,271,992
	Net loss per common share attributable to common stockholders:
	Basic and Diluted	$	(2.97	)	$	(0.99	)	$	(0.80	)
	The following have been excluded from the computation of basic and diluted net loss per share attributable to common stockholders as their effect would have been antidilutive:
		Year Ended December 31,
		2014			2013			2012
	Series A convertible redeemable preferred units		—			21,551,801			21,551,801
	Stock options		449,046			664,232			711,307
	Restricted stock		161,476			3,490,968			3,546,942
	Restricted stock units		4,542,231			5,255,113			1,979,763
			5,152,753			30,962,114			27,789,813

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Principles of Consolidation
	Principles of Consolidation
	The accompanying consolidated financial statements of Wayfair Inc. include its wholly owned subsidiaries including the accounts of Wayfair LLC and its wholly owned subsidiaries (collectively the Company or Wayfair). All intercompany accounts and transactions have been eliminated. Below is a summary of the wholly-owned subsidiaries of the Company with operations:
	Subsidiary		Location
	Wayfair LLC		USA
	Wayfair Securities Corporation		USA
	SK Retail, Inc.		USA
	Wayfair Stores Limited		Republic of Ireland
	Wayfair (UK) Limited		United Kingdom
	Wayfair GmbH		Germany
	Wayfair (BVI) Ltd.		British Virgin Islands
	Wayfair Australia Pty Limited		Australia
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, at the date of the financial statements, and the reported amounts of revenue and expenses during the reported period. On an ongoing basis, management evaluates these estimates and judgments, including those related to revenue recognition, capitalization of site and software development costs, stock-based compensation, and inventory. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with an original maturity (at the date of purchase) of three months or less to be the equivalent of cash for the purpose of consolidated balance sheets and statements of cash flows presentation. Cash equivalents, which consist primarily of money market accounts, are carried at cost, which approximates market value.
Restricted Cash	Restricted Cash
	As of December 31, 2014 and 2013, there was $0.3 million, and $0.8 million, respectively, of cash that was restricted from withdrawal and held by banks to guarantee the Company's letters of credit issued principally to secure certain property leases.
Short-Term Investments	Short-Term Investments
	Short-term investments consist of certificates of deposits with original maturities of greater than three months and mature in less than twelve months.
Accounts Receivable	Accounts Receivable
	Accounts receivable are stated at the amount management expects to collect from outstanding balances. The Company estimates the allowance for doubtful accounts based on historical losses, existing economic conditions, and other information available at the consolidated balance sheets dates. Uncollectible amounts are written off against the allowance after all collection efforts have been exhausted.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	The Company'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 the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. The Company measures its cash equivalents and short-term investments at fair value. The Company classifies its cash equivalents and short-term investments within Level 1 because the Company values these investments using quoted market prices. The fair value of the Company's Level 1 financial assets is based on quoted market prices of the identical underlying security. The Company does not have any assets or liabilities classified as Level 2 or Level 3 financial assets. See Note 3 for further details.
Concentrations of Credit Risk	Concentrations of Credit Risk
	Financial instruments that subject the Company to credit risk consist of cash and cash equivalents, short-term investments, and accounts receivable. The risk with respect to cash and cash equivalents and short-term investments is minimized by the Company's policy of investing in financial instruments (i.e., cash equivalents) with short-term maturities issued by highly rated financial institutions. At times, these balances may exceed federally insured limits; however, to date, the Company has not incurred any losses on these investments. As of December 31, 2014 and 2013, the Company had $2.1 million, and $2.6 million, respectively, in banks located outside the United States. The risk with respect to accounts receivable is managed by the Company through its policy of monitoring the creditworthiness of its customers to which it grants credit terms in the normal course of business.
Leases	Leases
	The Company leases office space in several countries around the world under non-cancelable lease agreements. The Company generally leases its office facilities under operating lease agreements. Office facilities subject to an operating lease and the related lease payments are not recorded on the balance sheet. The terms of certain lease agreements provide for rental payments on a graduated basis, however, the Company recognizes rent expense on a straight-line basis over the lease period in accordance with authoritative accounting guidance. Any lease incentives are recognized as reductions of rental expense on a straight-line basis over the term of the lease. The lease term begins on the date the Company becomes legally obligated for the rent payments or when it takes possession of the office space, whichever is earlier.
	The Company establishes assets and liabilities for the estimated construction costs incurred under lease arrangements where the Company is considered the owner for accounting purposes only, or build-to-suit leases, to the extent the Company is involved in the construction of structural improvements or take construction risk prior to commencement of a lease. Upon occupancy of facilities under build-to-suit leases, the Company assesses whether these arrangements qualify for sales recognition under the sale-leaseback accounting guidance. If the Company continues to be the deemed owner, the facilities are accounted for as financing leases.
Foreign Currency Translation	Foreign Currency Translation
	The functional currency of the Company is the United States dollar, while the functional currency of certain wholly-owned subsidiaries outside of the United States is as follows:
	Subsidiary		Currency
	Wayfair Stores Limited		Euro
	Wayfair (UK) Limited		Pound sterling
	Wayfair GmbH		Euro
	Wayfair (BVI) Ltd.		Euro
	Wayfair Australia Pty Limited		Australian dollar
	The financial statements of the Company are translated to United States dollars using year-end exchange rates as to assets and liabilities and average exchange rates as to revenue and expenses. Capital accounts are translated at their historical exchange rates when the capital transaction occurred. The effects of foreign currency translation are included in other comprehensive loss in the consolidated statements of comprehensive loss. Transaction gains and losses are included in the Company's consolidated statements of operations. Translation adjustments arising from the use of differing exchange rates from period to period are included in accumulated other comprehensive loss within total stockholders' equity (deficit).
Inventories	Inventories
	Inventories consisting of finished goods are stated at the lower of cost or market, determined by the first-in, first-out (FIFO) method, and consist of product for resale. Inventory costs consist of cost of product and inbound shipping and handling costs. Inventory costs also include direct and indirect labor costs, rents and depreciation expenses associated with the Company's fulfillment centers. Inventory valuation requires the Company to make judgments, based on currently-available information, about the likely method of disposition, such as through sales to individual customers, liquidations, and expected recoverable values of each disposition category.
Goods In-Transit	Goods In-Transit
	Goods in-transit directly from suppliers to customers are recorded in prepaid expenses and other current assets. Risk of loss and the transfer of title from the supplier to the Company occur at freight on board shipping point. As of December 31, 2014 and 2013, goods in-transit amounted to $19.6 million, and $9.7 million, respectively.
Property and Equipment	Property and Equipment
	Property and equipment are stated at cost, net of depreciation and amortization. Depreciation and amortization on property and equipment is calculated on the straight-line method over the estimated useful lives of the assets as follows:
	Class		Range of Life
			(In Years)
	Furniture and computer equipment		3 to 7
	Site and software development costs		2
	Leasehold improvements		The lesser of useful
			life or lease term
Site and Software Development Costs	Site and Software Development Costs
	The Company capitalizes costs associated with the development of its sites and internal-use software products after the preliminary project stage is complete and until the software is ready for its intended use. The capitalized costs are amortized over a two-year period. Costs incurred in the preliminary stages of development, after the software is ready for its intended use and for maintenance of internal-use software are expensed as incurred. Upgrade and enhancements are capitalized to the extent they will result in added functionality.
	Total costs capitalized, net of accumulated amortization, totaled $14.2 million, and $8.6 million as of December 31, 2014 and 2013, respectively, and are included in property and equipment, net in the accompanying consolidated balance sheets. Amortization expense for the years ended December 31, 2014, 2013 and 2012 were $9.9 million, $7.0 million, and $4.8 million, respectively. Capitalized software costs are included in property and equipment within our consolidated balance sheets.
Goodwill	Goodwill
	Goodwill represents the excess of cost over the fair value of tangible and identifiable intangible assets acquired and liabilities assumed. Goodwill is not amortized, but is subject to an annual impairment test, or more frequently as impairment indicators arise.
	The Company tests goodwill for impairment at least annually. The Company reviews goodwill for impairment on the last day of its fiscal year and whenever events or changes in circumstances indicate that the carrying amount of this asset may exceed its fair value. The assessment is performed at the reporting unit level. The Company first assesses qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, an entity determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then the two-step impairment test is not required. If the qualitative assessment requires the Company to perform the two-step goodwill impairment test to identify potential goodwill impairment then the first step is to compare the fair value of the reporting unit to the book value including goodwill. If the fair value of the reporting unit exceeds the book value, goodwill is not impaired. If the book value exceeds the fair value, the second step of the process is performed to measure the amount of impairment.
Long-Lived Assets	Long-Lived Assets
	The Company reviews long-lived assets for impairment whenever events or changes in circumstances, such as service discontinuance or technological obsolescence, indicate that the carrying amount of the long-lived asset may not be recoverable. When such events occur, the Company compares the carrying amount of the asset to the undiscounted expected future cash flows related to the asset. If the comparison indicates that an impairment exists, the amount of the impairment is calculated as the difference between the excess of the carrying amount over the fair value of the asset. If a readily determinable market price does not exist, fair value is estimated using discounted expected cash flows attributable to the asset. For the years ended December 31, 2014, 2013 and 2012, no impairment of long-lived assets or identifiable intangibles had been indicated.
Revenue Recognition	Revenue Recognition
	The Company generates net revenue through product sales generated primarily through the sites of the Company's five distinct brands and through sites operated by third parties.
	The Company recognizes revenue only when the following four criteria are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred; (3) the selling price is fixed or determinable; and (4) collectability is reasonably assured. The Company recognizes net revenue from sales of its products, upon delivery to the customer. The Company records product revenue at the gross amount as the Company is the primary obligor with the customer and provides the primary customer service for all products sold on its sites, has latitude in establishing price and selecting products sold on its sites, has discretion in selecting suppliers of products sold on its sites, maintains inventory risk from shipment through delivery date and upon accepting returns, and has credit risk. Net revenue includes shipping costs charged to the customer and is recorded net of taxes collected from customers, which are remitted to governmental authorities. Cash discounts, returns and rebates are deducted from gross revenue in determining net revenue. In addition, the Company defers revenue when cash is collected from its customer prior to the satisfaction of the revenue recognition criteria.
	The Company maintains a membership rewards program that allows enrolled customers to earn points which can be redeemed for future purchases. The Company defers a portion of its revenue associated with rewards that are ultimately expected to be redeemed prior to expiration.
	The Company also earns revenue through third-party advertisers that pay based on the number of advertisement related clicks, actions, or impressions for advertisements placed on the Company's sites. Revenue earned under these arrangements is included in net revenue and is recognized in the period in which the click, action, or impression occurs.
Vendor Rebates	Vendor Rebates
	The Company earns rebates under a volume incentive programs with its suppliers. These rebates are earned upon shipment of goods. Amounts earned and due from suppliers under these rebate programs are included in other current assets on the consolidated balance sheets and are reflected as a reduction of cost of goods sold on the consolidated statements of operations. Vendor allowances received by the Company reduce the carrying cost of inventory and are recognized in cost of goods sold when the related inventory is sold.
Costs of Goods Sold	Costs of Goods Sold
	Cost of goods sold consists of the cost of product sold to customers, shipping and handling costs and shipping supplies and fulfillment costs. Fulfillment costs include costs incurred in operating and staffing the fulfillment centers, such as costs attributed to receiving, inspecting, picking, packaging and preparing customer orders for shipment. Cost of goods sold also includes direct and indirect labor costs for fulfillment center oversight, including payroll and related benefit costs.
Advertising Costs	Advertising Costs
	Expenditures for advertising are expensed in the period that the advertising first takes place. Advertising expense amounted to approximately $191.3 million, $108.5 million, and $65.5 million in the years ended December 31, 2014, 2013 and 2012, respectively. Included in prepaid expenses at December 31, 2014, 2013 and 2012, are approximately $0.6 million, $0.5 million, and $0.9 million, respectively, of prepaid advertising costs.
Merchant Processing Fees	Merchant Processing Fees
	Merchant processing fees totaling $27.6 million, $19.4 million, and $13.3 million in the years ended December 31, 2014, 2013 and 2012, respectively, are included in customer service and merchant fees expense in the accompanying consolidated statements of operations. These fees are charged by third parties that provide merchant processing services for credit cards and debit cards.
Retail Partner Fees	Retail Partner Fees
	The Company sells its products through sites owned and operated by third-party online retailers, or retail partners. The Company pays a fee for sales generated through these sites and records them as merchant processing fees and advertising costs. Retail partner fees included in merchant processing fees are $4.4 million, $4.3 million, and $4.3 million for the years ended December 31, 2014, 2013 and 2012, respectively. Retail partner fees included in advertising costs are $24.3 million, $25.2 million, $22.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Equity-Based Compensation	Equity-Based Compensation
	The Company accounts for its equity-based compensation awards in accordance with ASC Topic 718, Compensation—Stock Compensation (ASC 718). ASC 718 requires all equity-based payments to employees, to be recognized as expense in the statements of operations based on their grant date fair values. The Company has granted stock options, restricted shares and restricted stock units.
	The Company estimated the grant date fair value of each common stock option award using the Black-Scholes option-pricing model. The use of the Black-Scholes option-pricing model required management to make assumptions with respect to the expected term of the option, the expected volatility of the common stock consistent with the expected life of the option, risk-free interest rates and expected dividend yields of the common stock. Until its IPO in October 2014, the fair value of restricted stock and restricted stock units on the date of grant was determined by the board. Since April 2011, the Company has only granted restricted stock units and has not granted any stock options or restricted stock. Since our IPO restricted stock unit values are determined based on the quoted market price of our common stock on the date of grant.
	Prior to the IPO the Company periodically determined for financial reporting purposes the estimated fair value of our common stock at various dates using contemporaneous valuations performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately Held Company Equity Securities Issued as Compensation, also known as the Practice Aid. The Company generally used the income and market approaches prescribed in the Practice Aid, in particular the income approach's discounted cash flow method, which was based on the Company's projections and estimated discount rate and the guideline public company, guideline transactions and precedent transaction methodologies, based on inputs from comparable public companies' equity valuations, comparable acquisition transactions and transactions in the Company's own equity securities, to estimate the enterprise value of the company. The Company performed these contemporaneous valuations as of December 31, 2011, June 30, 2012, December 31, 2012, June 30, 2013, September 30, 2013, December 31, 2013, March 31, 2014 and June 30, 2014.
	In connection with the preparation of the financial statements for the year ended December 31, 2013, the Company undertook a retrospective reassessment of the fair market value of its common stock for certain of its 2013 grants for financial reporting purposes. As part of that reassessment, the Company determined that the grant date fair values of its May, August and November 2013 grants to be $6.46, $10.88 and $20.87, respectively. The fair value previously determined at various valuation dates increased substantially in 2013 and there was no particular transaction or event that caused this increase. The grants made in May, August and November 2013 were between the dates when the Company performed its valuation. Accordingly, the Company calculated grant date fair value for these grants on a linear basis between each valuation date and believe it to be a reasonable method. Similarly in connection with the preparation of the financial statements for the quarter ended September 30, 2014, the Company undertook a retrospective reassessment of the fair market value of our common stock for our grants made in September 2014 to be equal to our October 2, 2014 IPO price of $29.00.
Income Taxes	Income Taxes
	Income taxes are accounted for under the asset and liability method. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases.
	Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The Company records valuation allowances to reduce deferred income tax assets to the amount that is more likely than not to be realized. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, no amount of benefit attributable to the position is recognized. The tax benefit to be recognized of any tax position that meets the more likely than not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency.
	Prior to the IPO, the Company's main operating entity had not been subject to U.S. federal income taxes as it was organized as a limited liability company. As such, the taxable income or loss was passed through to and included in the tax returns of the members. The Company was subject to entity level taxation in certain states, and certain domestic and foreign subsidiaries were subject to entity level U.S. and foreign income taxes. As a result of the internal restructuring prior to the IPO, a portion of the Company's income will be subject to U.S. federal, state, local, and foreign income taxes and taxed at the prevailing corporate tax rates.
Net Loss Attributable to Common Stockholders Per Share	Net Loss Attributable to Common Stockholders Per Share
	The Company follows the two-class method when computing net loss attributable to common stockholders per share as the Company had issued shares that meet the definition of participating securities which converted to common stock upon the IPO. Prior to the internal restructuring, the Company's convertible redeemable preferred units contractually entitled the holders of such units to participate in dividends, but did not contractually require the holders of such units to participate in losses of the Company. Accordingly, in periods prior to 2014 in which the Company reports a net loss or a net loss attributable to common shareholders resulting from preferred stock dividends or accretion, net losses are not allocated to participating securities. After the IPO the Company has continued to follow the two-class method because it has issued two classes of common stock—Class A and Class B.
	Basic net income (loss) attributable to common stockholders per share is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of common stock outstanding for the period. For periods in which the Company has reported net losses, diluted net loss per share attributable to common shareholders is the same as basic net loss per share attributable to common stockholders, since dilutive common stock are not assumed to have been issued if their effect is anti-dilutive.
Subsequent Events	Subsequent Events
	The Company considers events or transactions that have occurred after the balance sheet date of December 31, 2014, but prior to the filing of the financial statements with the Securities and Exchange Commission to provide additional evidence relative to certain estimates or to identify matters that require additional recognition or disclosure. Subsequent events have been evaluated through the filing of these financial statements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board ("FASB") issued a new accounting standard update that requires the presentation of certain unrecognized tax benefits as reductions to deferred tax assets rather than as liabilities in the consolidated balance sheets when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The Company adopted this new standard on a prospective basis in the first quarter of fiscal 2014, and the adoption of this accounting standard update did not have a material impact on the Company's consolidated financial statements.
	In May 2014, the FASB issued new accounting guidance regarding revenue recognition under GAAP. This new guidance will supersede nearly all existing revenue recognition guidance, and is effective for public entities for annual and interim periods beginning after December 31, 2016. Early adoption is not permitted. The Company is currently evaluating the impact of this new guidance on the Company's consolidated financial statements.
	In August 2014, the FASB issued Accounting Standards Update No. 2014-15, "Presentation of Financial Statements—Going Concern", which requires management to evaluate, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. ASU 2014-15 is effective for annual periods ending after December 15, 2016 and interim periods thereafter. Early application is permitted. The adoption of ASU 2014-15 is not expected to have a material effect on the consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Summary of the wholly-owned subsidiaries of the Company
	Subsidiary	Location
	Wayfair LLC	USA
	Wayfair Securities Corporation	USA
	SK Retail Inc.	USA
	Wayfair Stores Limited	Republic of Ireland
	Wayfair (UK) Limited	United Kingdom
	Wayfair GmbH	Germany
	Wayfair (BVI) Ltd.	British Virgin Islands
	Wayfair Australia Pty Limited	Australia
Summary of subsidiaries' functional currencies
	Subsidiary	Currency
	Wayfair Stores Limited	Euro
	Wayfair (UK) Limited	Pound sterling
	Wayfair GmbH	Euro
	Wayfair (BVI) Ltd.	Euro
	Wayfair Australia Pty Limited	Australian dollar
Schedule of estimated useful lives of plant, property and equipment
	Class	Range of Life
		(In Years)
	Furniture and computer equipment	3 to 7
	Site and software development costs	2
	Leasehold improvements	The lesser of useful
		life or lease term

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements
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
		December 31, 2014
		Total		Level 1		Level 2		Level 3
		(in thousands)
	Cash equivalents
	Money market funds	$	302,595	$	302,595		—		—
	Short-term investments:
	Certificates of deposit		60,000		60,000		—		—
	Restricted cash
	Money market funds		302		302		—		—
	Total	$	362,897	$	362,897	$	—	$	—
		December 31, 2013
		Total		Level 1		Level 2		Level 3
		(in thousands)
	Cash equivalents
	Money market funds	$	32,560	$	32,560		—		—
	Short-term investments:
	Certificates of deposit		50,019		50,019		—		—
	Restricted cash
	Money market funds		346		346		—		—
	Total	$	82,925	$	82,925	$	—	$	—

Intangible_assets_and_Goodwill1

Intangible assets and Goodwill (Tabless)	12 Months Ended
	Dec. 31, 2014
Intangible assets and Goodwill
Schedule of intangible assets	Intangible assets consisted of the following as of December 31, 2013 and 2014 (in thousands):
		Weighted-		December 31, 2014							December 31, 2013
		Average
		Amortization
		Period
		(Years)		Gross		Accumulated			Net Book		Gross		Accumulated			Net Book
				Carrying		Amortization			Value		Carrying		Amortization			Value
				Value							Value
	Trademarks	5		$	2,001	$	(604	)	$	1,397	$	2,030	$	(219	)	$	1,811
	Customer relationships	5			1,300		(368	)		932		1,300		(108	)		1,192
	Non-compete agreements	3 - 5			108		(52	)		56		110		(19	)		91
	Technology	5			718		(467	)		251		920		(430	)		490
	Other intangibles	3			373		(158	)		215		373		(47	)		326
	Domain names	5			2,687		(2,684	)		3		2,695		(2,686	)		9
	Total			$	7,187	$	(4,333	)	$	2,854	$	7,428	$	(3,509	)	$	3,919
Summary of the estimated aggregate amortization expense in future years
	The following is a summary of the estimated aggregate amortization expense in future years at December 31, 2014 (in thousands):
	2015	$	961
	2016		880
	2017		640
	2018 and thereafter		373
		$	2,854

Property_and_Equipment_net_Tab

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2014
Property and Equipment, net
Schedule of property and equipment, net		December 31,
		2014			2013
		(in thousands)
	Furniture and computer equipment	$	48,399		$	26,218
	Site and software development costs		36,294			23,715
	Leasehold improvements		14,290			1,912
	Construction in progress		4,800			184
			103,783			52,029
	Less accumulated depreciation and amortization		(43,144	)		(29,941	)
	Property and equipment, net	$	60,639		$	22,088

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2014
Accrued Expenses
Schedule of accrued expenses
		December 31,
		2014		2013
		(in thousands)
	Employee compensation and related benefits	$	15,244	$	9,517
	Marketing		9,561		5,329
	Accrued property, plant and equipment		7,151		—
	Merchant processing fees		3,560		2,213
	Audit, legal and professional fees		898		377
	Other accrued expenses		5,921		3,939
		$	42,335	$	21,375

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Schedule of future lease payments under non-cancelable operating leases	Future lease payments under non-cancelable leases are as follows as of December 31, 2014:
		Amount
		(in thousands)
	2015	$	13,303
	2016		15,596
	2017		15,245
	2018		15,337
	2019		13,970
	Thereafter		53,936
		$	127,387

EquityBased_Compensation_Table

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Equity based compensation
Summary of status and activity for awards of stock options
		Stock			Weighted-Average		Weighted-Average
		Options			Exericse Price		Remaining
							Contractual Term
							(Years)
	Outstanding at December 31, 2013		664,232		$	2.99		6.7
	Exercised		(177,704	)	$	2.99
	Repurchased		(9,028	)	$	2.93
	Forfeited/cancelled		(28,454	)	$	3.11
	Outstanding at December 31, 2014		449,046		$	2.98		6.5
	Exercisable at December 31, 2014		409,567		$	2.96		6.5
	Expected to vest as of December 31, 2014		26,277		$	3.1		6.5
Restricted Common Stock
Equity based compensation
Summary of status and activity for awards of stock options
		Restricted			Weighted-Average
		Stock			Grant Date
					Fair Value
	Unvested at December 31, 2013		3,490,968		$	4.75
	Vested		(3,022,912	)	$	4.75
	Repurchased		(202,757	)	$	4.75
	Forfeited/cancelled		(103,823	)	$	4.75
	Unvested at December 31, 2014		161,476		$	4.75
	Expected to vest as of December 31, 2014		109,150		$	4.75
RSU
Equity based compensation
Summary of status and activity for awards of restricted stock units	Summary of status and activity for awards of restricted stock units
		Restricted			Weighted-Average		Weighted-Average
		Stock Units			Grant Date		Remaining
					Fair Value		Contractual Term
							(Years)
	Unvested at December 31, 2013		5,255,113		$	7.95		6
	Granted		1,953,227		$	27.07
	Vested		(2,198,857	)	$	7.89
	Forfeited/cancelled		(467,252	)	$	12.31
	Unvested at December 31, 2014		4,542,231		$	17.67		5.6
	Expected to vest as of December 31, 2014		3,394,145		$	18.11		5.7

Segment_and_Geographic_Informa1

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2014
Segment and Geographic Information
Schedule of operating information by segment
		Year Ended December 31,
		2014		2013		2012
		(in thousands)
	Net revenue
	Direct Retail	$	1,101,686	$	673,446	$	389,290
	Other		217,265		242,397		211,738
	Net revenue	$	1,318,951	$	915,843	$	601,028
Schedule of revenue and long-lived assets by geographic area
		Year Ended December 31,
		2014		2013		2012
		(in thousands)
	Geographic net revenue:
	United States	$	1,236,215	$	857,001	$	542,736
	International		82,736		58,842		58,292
	Total	$	1,318,951	$	915,843	$	601,028
		Year Ended
		December 31,
		2014		2013
		(in thousands)
	Geographic long-lived assets:
	United States	$	59,013	$	21,451
	International		1,626		637
	Total	$	60,639	$	22,088

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Schedule of income tax expense (benefit) attributable to income (loss) from operation	Income tax expense (benefit) for the years ended December 31, 2014, 2013 and 2012 attributable to income (loss) from operation is presented below (in thousands):
	Year ended December 31, 2014	Current			Deferred			Total
	Federal	$	—		$	32		$	32
	State		1			4			5
	Foreign		138			—			138
		$	139		$	36		$	175
	Year ended December 31, 2013	Current			Deferred			Total
	Federal	$	—		$	—		$	—
	State		1			—			1
	Foreign		41			4			45
		$	42		$	4		$	46
	Year ended December 31, 2012	Current			Deferred			Total
	Federal	$	—		$	—		$	—
	State		—			—			—
	Foreign		50			—			50
			50			—			50
Schedule of difference in the company's expected tax expense (benefit) as computed by applying the U.S. federal corporate rate to income before tax expense (benefit), and actual tax is reconciled	The actual income tax expense (benefit) differs from the expected income tax expense (benefit) computed by applying the United States Federal corporate income tax rate of 35% to income before tax expense (benefit) as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Computed expected tax expense (benefit)	$	(51,773	)	$	(5,417	)	$	(7,352	)
	Decrease in income taxes resulting from:		—			—			—
	Partnership losses not creating tax benefit		21,369			3,920			4,620
	Effect of conversion to C-corporation		(28,034	)		—			—
	State income tax expense, net of federal benefit		(2,517	)		(269	)		—
	Foreign tax rate differential		2,826			619			1,500
	Restricted stock expense		5,555			—			—
	Change in valuation allowance		52,921			1,418			1,199
	Other		(172	)		(225	)		83
	Net income tax expense (benefit)	$	175		$	46		$	50
Schedule of components of income tax expense (benefit) determined by tax jurisdiction	The components of results of income before income tax expense (benefit) determined by tax jurisdiction, are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	United States	$	(128,505	)	$	(9,895	)	$	(13,299	)
	Foreign		(19,418	)		(5,585	)		(7,706	)
	Total	$	(147,923	)	$	(15,480	)	$	(21,005	)
Schedule of tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities for the periods	The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities for the periods presented are as follows (in thousands):
		December 31
		2014			2013
	Deferred tax asset:
	Accounts receivable, due to allowance for doubtful accounts	$	1,009		$	—
	Inventories		295			—
	Operating loss carry-forwards		17,939			6,901
	Stock-based compensation expense		11,529			—
	Intangibles due to differences in amortization		26,557			—
	Accrued Expenses/Other		3,555			1
	Charitable Contributions		18			—
	Deferred Rent		7,161			—
	Gross deferred tax asset		68,063			6,902
	Less: Valuation allowance		(58,980	)		(6,902	)
	Net deferred tax asset		9,083			—
	Deferred tax liability:
	Prepaid expenses		(783	)		—
	Capitalized technology		(5,019	)		—
	Property and equipment, due to difference in depreciation		(3,281	)		—
	Tax-deductible goodwill		(36	)		—
	Total deferred tax liabilities		(9,119	)		—
	Net deferred tax assets		(36	)
	Current net deferred tax asset		(55	)		—
	Current net deferred tax liability		—			—
	Non-current net deferred tax asset		19			—
	Non-current net deferred tax liability		—			—
			(36	)		—

Net_Loss_per_Share_Tables

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Net Loss per Share
Schedule of calculation of basic and diluted net loss per share	The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data):
		Year Ended December 31,
		2014			2013			2012
	Numerator:
	Net loss	$	(148,098	)	$	(15,526	)	$	(21,055	)
	Accretion of preferred units to redemption value	$	(2,071	)	$	(25,388	)	$	(12,154	)
	Net loss attributable to common stockholders per share—basic and diluted	$	(150,169	)	$	(40,914	)	$	(33,209	)
	Denominator:
	Weighted average shares used for basic and diluted net loss per share computation		50,641,601			41,331,546			41,271,992
	Net loss per common share attributable to common stockholders:
	Basic and Diluted	$	(2.97	)	$	(0.99	)	$	(0.80	)
Schedule of computation of basic and diluted net loss per share attributable to common stockholders as their effect would have been antidilutive
		Year Ended December 31,
		2014			2013			2012
	Series A convertible redeemable preferred units		—			21,551,801			21,551,801
	Stock options		449,046			664,232			711,307
	Restricted stock		161,476			3,490,968			3,546,942
	Restricted stock units		4,542,231			5,255,113			1,979,763
			5,152,753			30,962,114			27,789,813

Basis_of_Presentation_Details

Basis of Presentation (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2011	Dec. 31, 2013
	item
Basis Of Presentation
Minimum number of products offered	7,000,000
Minimum number of suppliers providing products offered	7,000
Increase in accumulated deficit		$0.30
Due to related party			1.9
Adjustments made in additional paid in capital due to reclassification	$306.20

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014
	item
Restricted Cash
Restricted cash	$300,000	$800,000
Concentrations of Credit Risk
Cash and cash equivalents and short-term investments held in banks located outside the U.S.	2,100,000	2,600,000
Goods In-Transit
Goods in-transit	19,600,000	9,700,000
Property, plant and equipment
Property and equipment, net	60,639,000	22,088,000
Goodwill
Impairment of goodwill		0	0
Long-Lived Assets
Impairment of long-lived assets or identifiable intangibles	0	0	0
Advertising Costs
Advertising expense	191,284,000	108,469,000	65,504,000
Prepaid advertising costs	600,000	500,000	900,000
Merchant Processing Fees
Merchant processing fees	27,600,000	19,400,000	13,300,000
Retail Partner Fees
Retail partner fees included in merchant processing fees	4,400,000	4,300,000	4,300,000
Retail partner fees included in advertising costs	24,300,000	25,200,000	22,000,000
Net Loss per Share
Number of classes of common stock	2
May-13
Equity Based Compensation
Grant-date fair value		$6.46
Aug-13
Equity Based Compensation
Grant-date fair value		$10.88
Nov-13
Equity Based Compensation
Grant-date fair value		$20.87
Sep-14
Equity Based Compensation
Grant-date fair value				$29
Australia
Goodwill
Impairment of goodwill	800,000
Goodwill	1,700,000
Furniture and computer equipment | Minimum
Property, plant and equipment
Estimated useful lives	3 years
Furniture and computer equipment | Maximum
Property, plant and equipment
Estimated useful lives	7 years
Site and software development costs
Property, plant and equipment
Estimated useful lives	2 years
Property and equipment, net	14,200,000	8,600,000
Amortization expense	$9,900,000	$7,000,000	$4,800,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Fair value measurements
Goodwill impairment charges	$0	$0
Australia
Fair value measurements
Goodwill impairment charges			800,000
Recurring basis
Fair value measurements
Total assets	82,925,000		362,897,000
Recurring basis | Cash equivalents
Fair value measurements
Money market funds	32,560,000		302,595,000
Recurring basis | Short-term investments Member
Fair value measurements
Certificates of deposit	50,019,000		60,000,000
Recurring basis | Restricted cash
Fair value measurements
Money market funds	346,000		302,000
Recurring basis | Level 1
Fair value measurements
Total assets	82,925,000		362,897,000
Recurring basis | Level 1 | Cash equivalents
Fair value measurements
Money market funds	32,560,000		302,595,000
Recurring basis | Level 1 | Short-term investments Member
Fair value measurements
Certificates of deposit	50,019,000		60,000,000
Recurring basis | Level 1 | Restricted cash
Fair value measurements
Money market funds	346,000		302,000
Nonrecurring basis | Australia | Level 3
Fair value measurements
Goodwill impairment charges			$800,000

Intangible_assets_and_Goodwill2

Intangible assets and Goodwill (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Intangible assets
Gross Carrying Value	$7,187,000	$7,428,000
Accumulated Amortization	-4,333,000	-3,509,000
Total	2,854,000	3,919,000
Future estimated amortization expense
2015	961,000
2016	880,000
2017	640,000
2018	373,000
Total	2,854,000	3,919,000
Goodwill
Impairment of goodwill		0	0
Reduction in goodwill due to foreign exchange fluctuations and impairment	700,000
Australia
Goodwill
Impairment of goodwill	800,000
Goodwill	1,700,000
Trademarks
Intangible assets
Weighted-Average Amortization Period	5 years
Gross Carrying Value	2,001,000	2,030,000
Accumulated Amortization	-604,000	-219,000
Total	1,397,000	1,811,000
Future estimated amortization expense
Total	1,397,000	1,811,000
Customer relationships
Intangible assets
Weighted-Average Amortization Period	5 years
Gross Carrying Value	1,300,000	1,300,000
Accumulated Amortization	-368,000	-108,000
Total	932,000	1,192,000
Future estimated amortization expense
Total	932,000	1,192,000
Non-compete agreements
Intangible assets
Gross Carrying Value	108,000	110,000
Accumulated Amortization	-52,000	-19,000
Total	56,000	91,000
Future estimated amortization expense
Total	56,000	91,000
Non-compete agreements | Minimum
Intangible assets
Weighted-Average Amortization Period	3 years
Non-compete agreements | Maximum
Intangible assets
Weighted-Average Amortization Period	5 years
Technology
Intangible assets
Weighted-Average Amortization Period	5 years
Gross Carrying Value	718,000	920,000
Accumulated Amortization	-467,000	-430,000
Total	251,000	490,000
Future estimated amortization expense
Total	251,000	490,000
Other intangibles
Intangible assets
Weighted-Average Amortization Period	3 years
Gross Carrying Value	373,000	373,000
Accumulated Amortization	-158,000	-47,000
Total	215,000	326,000
Future estimated amortization expense
Total	215,000	326,000
Domain names
Intangible assets
Weighted-Average Amortization Period	5 years
Gross Carrying Value	2,687,000	2,695,000
Accumulated Amortization	-2,684,000	-2,686,000
Total	3,000	9,000
Future estimated amortization expense
Total	$3,000	$9,000

Property_and_Equipment_net_Det

Property and Equipment, net (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and equipment, net
Property and equipment, gross	$103,783,000	$52,029,000
Less accumulated depreciation and amortization	-43,144,000	-29,941,000
Property and equipment, net	60,639,000	22,088,000
Depreciation and amortization	20,800,000	12,500,000	8,600,000
Furniture and computer equipment
Property and equipment, net
Property and equipment, gross	48,399,000	26,218,000
Site and software development costs
Property and equipment, net
Property and equipment, gross	36,294,000	23,715,000
Property and equipment, net	14,200,000	8,600,000
Leasehold improvements
Property and equipment, net
Property and equipment, gross	14,290,000	1,912,000
Construction in progress
Property and equipment, net
Property and equipment, gross	$4,800,000	$184,000

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Expenses
Employee compensation and related benefits	$15,244	$9,517
Marketing	9,561	5,329
Accrued property, plant and equipment	7,151
Credit card	3,560	2,213
Audit, legal and professional fees	898	377
Other accrued expenses	5,921	3,939
Total accrued expenses	$42,335	$21,375

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Sep. 30, 2014
				sqft	sqft
Operating leases
Rental expense under operating leases	$11,400,000	$4,600,000	$3,000,000
Letter of credit issued as security for lease agreements	3,300,000
Future minimum lease payments under non cancelable operating leases
2015	13,303,000
2016	15,596,000
2017	15,245,000
2018	15,337,000
2019	13,970,000
Thereafter	53,936,000
Total	127,387,000
Minimum sublease rentals	1,100,000
Boston lease extend option for 2 successive periods of	5 years
Construction In Progress	3,900,000
Construction Payable	$3,900,000
Office space | Boston, MA
Operating leases
Area of space (in square feet)				275,000
Office space | Ogden, UT
Operating leases
Area of space (in square feet)					180,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 2) (Sales and other similar tax assessments, USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Sales and other similar tax assessments
Contingencies
Aggregate amount of claims	$11.70

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Benefit Plans
Age of the full-time employees qualified to participate in the defined contribution plan	21 years
Expense related to savings plan recognized	$2.40	$1.80	$1.50
Maximum
Employee Benefit Plans
Matching contribution by employer as a percentage of employee's considered compensation	4.00%

EquityBased_Compensation_Detai

Equity-Based Compensation (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Oct. 07, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2014
			item
Equity based compensation
Number of vesting triggers			2
Service period			5 years
Share based compensation expenses	$55,300,000	$0
Cost of Goods Sold			1,007,853,000	691,602,000	455,879,000
Customer Service And Merchant Fees			55,804,000	35,500,000	25,730,000
Merchandising marketing and sales			80,113,000	33,506,000	22,136,000
Technology Operations General And Administrative Expense			130,701,000	62,246,000	52,961,000
2014 Plan
Equity based compensation
Number of shares authorized	8,603,066		8,603,066
Shares issued under plan			0
Vesting period			5 years
Property and equipment net | Site and software development costs
Equity based compensation
Share based compensation expenses	1,400,000
Common Stock Options
Common stock options
Outstanding at the beginning of the period (in shares)		664,232	664,232
Exercised (in shares)			-177,704
Repurchased (in shares)			-9,028
Forfeited/cancelled (in shares)			-28,454
Outstanding at the end of the period (in shares)	449,046		449,046	664,232
Exercisable at the end of the period (in shares)	409,567		409,567
Expected to vest at the end of the period (in shares)	26,277		26,277
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (in dollars per share)		$2.99	$2.99
Exercised (in dollars per share)			$2.99
Repurchased (in dollars per share)			$2.93
Forfeited/canceled (in dollars per share)			$3.11
Outstanding at the end of the period (in dollars per share)	$2.98		$2.98	$2.99
Exercisable at the end of the period (in dollars per share)	$2.96		$2.96
Expected to vest at the end of the period (in dollars per share)	$3.10		$3.10
Weighted-Average Remaining Contractual Term (Years)
Outstanding at the beginning of the period			6 years 6 months	6 years 8 months 12 days
Outstanding at the end of the period			6 years 6 months	6 years 8 months 12 days
Exercisable at the end of the period			6 years 6 months
Expected to vest at the end of the period			6 years 6 months
Additional disclosures
Aggregate intrinsic value of stock options exercised			4,300,000
Aggregate intrinsic value of stock options outstanding and repurchased	7,600,000		7,600,000
Aggregate intrinsic value of stock options exercisable	6,900,000		6,900,000
Weighted average remaining vesting term for options expected to vest			3 months 18 days
Common Stock Options | Maximum
Additional disclosures
Unrecognized share-based compensation	100,000		100,000
Common stock options and restricted common stocks
Equity based compensation
Share based compensation expenses			5,500,000
Weighted-Average Remaining Contractual Term (Years)
Tender offer price per unit						$26.23
Payments of repurchase of stock						5,500,000
Compensation charge			$5,500,000

EquityBased_Compensation_Detai1

Equity-Based Compensation (Details 2) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restricted Common Stock
Restricted stock and units
Unvested at the beginning of the period (in shares)	3,490,968
Vested (in shares)	-3,022,912
Repurchased (in shares)	-202,757
Forfeited/cancelled (in shares)	-103,823
Unvested at the end of the period (in shares)	161,476
Expected to vest at the end of the period (in shares)	109,150
Weighted-Average Grant-Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$4.75
Vested (in dollars per share)	$4.75
Repurchased (in dollars per share)	$4.75
Forfeited/cancelled (in dollars per share)	$4.75
Unvested at the end of the period (in dollars per share)	$4.75
Expected to vest at the end of the period (in dollars per share)	$4.75
Additional information
Intrinsic value of stock vested and repurchased	$101.50
Aggregate intrinsic value	3.2
Weighted average remaining vesting term for options expected to vest	2 months 12 days
Restricted Common Stock | Maximum
Additional information
Unrecognized share-based compensation	0.1
RSU
Restricted stock and units
Unvested at the beginning of the period (in shares)	5,255,113
Granted (in shares)	1,953,227
Vested (in shares)	-2,198,857
Forfeited/cancelled (in shares)	-467,252
Unvested at the end of the period (in shares)	4,542,231	5,255,113
Expected to vest at the end of the period (in shares)	3,394,145
Weighted-Average Grant-Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$7.95
Granted (in dollars per share)	$27.07
Vested (in dollars per share)	$7.89
Forfeited/cancelled (in dollars per share)	$12.31
Unvested at the end of the period (in dollars per share)	$17.67	$7.95
Expected to vest at the end of the period (in dollars per share)	$18.11
Weighted-Average Remaining Contractual Term (Years)
Unvested at the beginning of the period	5 years 7 months 6 days	6 years
Unvested at the end of the period	5 years 7 months 6 days	6 years
Expected to vest at the end of the period	5 years 8 months 12 days
Additional information
Aggregate intrinsic value	90.2
Unrecognized share-based compensation	38.2
Weighted average remaining vesting term for options expected to vest	1 year 8 months 12 days
Intrinsic value of stock vested	$69

Stockholders_Equity_Deficit1

Stockholders' Equity (Deficit) (USD $)	12 Months Ended	0 Months Ended	3 Months Ended	1 Months Ended		12 Months Ended
	Dec. 31, 2014	Oct. 07, 2014	Dec. 31, 2014	Oct. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Members' deficit
Preferred stock, shares authorized	10,000,000		10,000,000
Preferred stock, par value (in dollars per share)	$0.00		$0.00
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0		0
Common stock
Net proceeds from initial public offering	$282,893,000
Class A common stock
Common stock
Common stock, shares authorized	500,000,000		500,000,000			0
Common stock, par value (in dollars per unit)	$0.00		$0.00			$0.00
Common stock, shares outstanding	37,002,874		37,002,874			0
Number of votes each holder is entitled	1
Class A common stock | Initial Public Offering
Common stock
Initial public offering, aggregate number of shares of common stock sold		12,650,000
Share issue price (in dollars per share)		$29
Number of shares of common stock sold		10,500,000
Number of shares of stock sold by the selling shareholders		2,150,000
Number of shares of sold by the selling shareholders pursuant to an option granted to the underwriters to purchase additional shares		1,650,000
Net proceeds from initial public offering		282,900,000
Class B common stock
Common stock
Common stock, shares authorized	164,000,000		164,000,000			0
Common stock, par value (in dollars per unit)	$0.00		$0.00			$0.00
Common stock, shares outstanding	46,179,192		46,179,192			0
Number of votes each holder is entitled	10
Conversion ratio	1
Conversion ratio following the completion of the offering	1
Conversion ratio upon transfer	1
Number of shares converted into Class A shares			24,352,874
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%
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 (as a percent)	10.00%
Class A and Class B Common stock
Common stock
Common stock, shares outstanding	83,182,066		83,182,066
Common units | Class B common stock
Members' deficit
Conversion of units to common stock (in shares)	44,904,110
Series A convertible redeemable preferred units
Members' deficit
Accretion of convertible redeemable preferred units	14,417,000					25,388,000	12,154,000
Accrued dividend distribution				24,500,000	15,000,000
Series A and Series B convertible redeemable preferred units
Members' deficit
Reduction of accretion expenses	14,800,000
Series A and Series B convertible redeemable preferred units | Class B common stock
Members' deficit
Conversion of units to common stock (in shares)	27,546,934
Series B convertible redeemable preferred units
Members' deficit
Accretion of convertible redeemable preferred units	$2,455,000

Segment_and_Geographic_Informa2

Segment and Geographic Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	item
Segment and Geographic Information
Number of operating segment	1
Number of reportable segment	1
Direct Retail	$1,101,686	$673,446	$389,290
Other	217,265	242,397	211,738
Net revenue	$1,318,951	$915,843	$601,028

Segment_and_Geographic_Informa3

Segment and Geographic Information (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Geographic analysis, revenue and long-lived assets
Geographic net revenue	$1,318,951	$915,843	$601,028
Geographic long-lived assets	60,639	22,088
United States
Geographic analysis, revenue and long-lived assets
Geographic net revenue	1,236,215	857,001	542,736
Geographic long-lived assets	59,013	21,451
International
Geographic analysis, revenue and long-lived assets
Geographic net revenue	82,736	58,842	58,292
Geographic long-lived assets	$1,626	$637

Income_Taxes_Detail

Income Taxes (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current income tax expense (benefit)
Current state income tax expense (benefit)	$1,000	$1,000
Current foreign income tax expense (benefit)	138,000	41,000	50,000
Current income tax expense (benefit)	139,000	42,000	50,000
Deferred income tax expense (benefit)
Deferred federal income tax expense (benefit)	32,000
Deferred state income tax expense (benefit)	4,000
Deferred foreign income tax expense (benefit)		4,000
Deferred income tax expense (benefit)	36,000	4,000
Income tax expense (benefit)
Federal income tax expense (benefit), Total	32,000
State income tax expense (benefit), Total	5,000	1,000
Foreign income tax expense (benefit), Total	138,000	45,000	50,000
Net income tax expense (benefit)	175,000	46,000	50,000
Reconciliation of the U.S. federal corporate rate to to income before tax expense (benefit), and actual tax
U.S. federal corporate rate	35.00%
Computed expected tax expense (benefit)	-51,773,000	-5,417,000	-7,352,000
Decrease in income taxes resulting from:
Partnership losses not creating tax benefit	21,369,000	3,920,000	4,620,000
Effect of conversion to C- corporation	-28,034,000
State income tax expense, net of federal benefit	-2,517,000	-269,000
Foreign tax rate differential	2,826,000	619,000	1,500,000
Restricted stock expense	5,555,000
Change in valuation allowance	52,921,000	1,418,000	1,199,000
Other	-172,000	-225,000	83,000
Net income tax expense (benefit)	175,000	46,000	50,000
Income (loss) from continuing operations:
United States	-128,505,000	-9,895,000	-13,299,000
Foreign	-19,418,000	-5,585,000	-7,706,000
Total	-147,923,000	-15,480,000	-21,005,000
Deferred tax asset:
Accounts receivable, due to allowance for doubtful accounts	1,009,000
Inventories	295,000
Operating loss carry-forwards	17,939,000	6,901,000
Stock-based compensation expense	11,529,000
Intangibles due to differences in amortization	26,557,000
Accrued Expenses/Other	3,555,000	1,000
Charitable Contributions	18,000
Deferred Rent	7,161,000
Gross deferred tax asset	68,063,000	6,902,000
Less: Valuation allowance	-58,980,000	-6,902,000
Net deferred tax asset	9,083,000
Deferred tax liabilities:
Prepaid expenses	-783,000
Capitalized technology	-5,019,000
Property and equipment, due to difference in depreciation	-3,281,000
Tax-deductible goodwill	-36,000
Total deferred tax liabilities	-9,119,000
Net deferred tax assets	-36,000
Current net deferred tax asset	-55,000
Non-current net deferred tax asset	19,000
Federal net operating loss carryforwards	84,900,000
Federal net operating loss carryforward that will result in increase to additional paid-in capital	60,200,000
State net operating loss carryforwards	81,200,000
State net operating loss carryforward that will result in increase to additional paid-in capital	57,500,000
Foreign operating loss carryforwards	46,900,000
Increase in valuation allowance	52,100,000
Undistributed earnings of the entity's foreign subsidiaries	900,000
Gross unrecognized tax benefits	200,000	200,000
Unrecognized tax benefits, if recognized, would result in a reduction of the entity's effective tax rate	200,000
Deferred tax liabilities	-36,000
Maximum
Deferred tax liabilities:
Accrued interest and penalties related to tax positions	$100,000

Credit_Agreement_Details

Credit Agreement (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Credit agreement
Credit agreement amount outstanding	$0	$0	$0
Line of credit
Credit agreement
Maximum borrowing capacity	25,000,000
Revolving line of credit
Credit agreement
Maximum borrowing capacity	10,000,000
Credit card program
Credit agreement
Maximum borrowing capacity	$15,000,000

RelatedParty_Transactions_Deta

Related-Party Transactions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue Sharing Agreement Member
Related party transactions
Transactions with related party			$2,000
Supplier Relationship
Related party transactions
Transactions with related party	$200	$4,000	$21,000

Net_Loss_per_Share_Details

Net Loss per Share (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	5,152,753	30,962,114	27,789,813
Numerator:
Net loss	($148,098)	($15,526)	($21,055)
Accretion of preferred units to redemption value	-2,071	-25,388	-12,154
Net loss attributable to common stockholders	-150,169	-40,914	-33,209
Denominator:
Weighted average units used for basic and diluted net loss per unit computation (in units)	50,641,601	41,331,546	41,271,992
Net loss per common unit attributable to common unit holders:
Basic and Diluted (in dollars per unit)	($2.97)	($0.99)	($0.80)
Series A convertible redeemable preferred units
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	0	21,551,801	21,551,801
Common Stock Options
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	449,046	664,232	711,307
Restricted Common Stock
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	161,476	3,490,968	3,546,942
RSU
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	4,542,231	5,255,113	1,979,763
Class A common stock
Anti-dilutive securities
Number of votes each holder is entitled	1
Class B common stock
Anti-dilutive securities
Number of votes each holder is entitled	10
Written consent percentage required of Class B outstanding shares for conversion to Class A	66.667
Conversion ratio to Class A	1
Numerator:
Net loss	-148,098
Accretion of preferred units to redemption value	-2,071
Net loss attributable to common stockholders	($150,169)
Denominator:
Weighted average units used for basic and diluted net loss per unit computation (in units)	50,641,601
Net loss per common unit attributable to common unit holders:
Basic and Diluted (in dollars per unit)	($2.97)