Zillow (Z) 10-Q 6 Aug 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Jul. 30, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	001-36853
Entity Registrant Name	ZILLOW GROUP, INC.
Entity Central Index Key	0001617640
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	47-1645716
Entity Address, Address Line One	1301 Second Avenue
Entity Address, Address Line Two	Floor 31
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98101
City Area Code	206
Local Phone Number	470-7000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Class A Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Class A Common Stock, par value $0.0001 per share
Trading Symbol	ZG
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		60,002,842
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		6,217,447
Class C Capital Stock
Entity Information [Line Items]
Title of 12(b) Security	Class C Capital Stock, par value $0.0001 per share
Trading Symbol	Z
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		160,765,729

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 2,045,474	$ 1,141,263
Short-term investments	1,491,167	1,280,989
Accounts receivable, net of allowance for doubtful accounts of $2,282 and $4,522 at June 30, 2020 and December 31, 2019, respectively	66,878	67,005
Mortgage loans held for sale	75,021	36,507
Inventory	135,401	836,627
Prepaid expenses and other current assets	56,373	58,117
Restricted cash	33,620	89,646
Total current assets	3,903,934	3,510,154
Contract cost assets	47,747	45,209
Property and equipment, net	195,747	170,489
Right of use assets	199,422	212,153
Goodwill	1,984,907	1,984,907
Intangible assets, net	106,990	190,567
Other assets	11,041	18,494
Total assets	6,449,788	6,131,973
Current liabilities:
Accounts payable	14,307	8,343
Accrued expenses and other current liabilities	74,646	85,442
Accrued compensation and benefits	34,520	37,805
Borrowings under credit facilities	187,032	721,951
Deferred revenue	44,514	39,747
Lease liabilities, current portion	22,789	17,592
Convertible senior notes, current portion	9,637	9,637
Total current liabilities	387,445	920,517
Lease liabilities, net of current portion	214,752	220,445
Convertible senior notes, net of current portion	1,810,341	1,543,402
Deferred tax liabilities and other long-term liabilities	14,192	12,188
Total liabilities	2,426,730	2,696,552
Commitments and contingencies (Note 17)
Shareholders’ equity:
Preferred stock, $0.0001 par value; 30,000,000 shares authorized; no shares issued and outstanding	0	0
Additional paid-in capital	5,246,371	4,412,200
Accumulated other comprehensive income	1,525	340
Accumulated deficit	(1,224,861)	(977,140)
Total shareholders’ equity	4,023,058	3,435,421
Total liabilities and shareholders’ equity	6,449,788	6,131,973
Class A Common Stock
Shareholders’ equity:
Common stock/capital stock	6	6
Class B Common Stock
Shareholders’ equity:
Common stock/capital stock	1	1
Class C Capital Stock
Shareholders’ equity:
Common stock/capital stock	$ 16	$ 14

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Allowance for doubtful accounts	$ 2,282	$ 4,522
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (in shares)	30,000,000	30,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Class A Common Stock
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	1,245,000,000	1,245,000,000
Common stock, issued (in shares)	59,850,004	58,739,989
Common stock, outstanding (in shares)	59,850,004	58,739,989
Class B Common Stock
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	15,000,000	15,000,000
Common stock, issued (in shares)	6,217,447	6,217,447
Common stock, outstanding (in shares)	6,217,447	6,217,447
Class C Capital Stock
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	600,000,000	600,000,000
Common stock, issued (in shares)	159,974,485	144,109,419
Common stock, outstanding (in shares)	159,974,485	144,109,419

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Revenue:
Revenue		$ 768,352		$ 599,578		$ 1,894,173	$ 1,053,682
Cost of revenue (exclusive of amortization)
Cost of revenue		461,071	[1]	271,221	[1]	1,222,743	422,569
Sales and marketing		155,598		187,433		360,246	349,020
Technology and development		128,857		120,330		263,775	228,100
General and administrative		85,511		82,839		177,796	178,613
Impairment costs		0		0		76,800	0
Integration costs		0		293		0	645
Total costs and expenses		831,037		662,116		2,101,360	1,178,947
Loss from operations		(62,685)		(62,538)		(207,187)	(125,265)
Gain on partial extinguishment of 2021 Notes		6,391		0		6,391	0
Other income		10,115		9,458		19,708	18,626
Interest expense		(37,590)		(18,897)		(75,182)	(35,363)
Loss before income taxes		(83,769)		(71,977)		(256,270)	(142,002)
Income tax benefit (expense)		(679)		0		8,549	2,500
Net loss		$ (84,448)		$ (71,977)		$ (247,721)	$ (139,502)
Net loss per share - basic and diluted (usd per share)		$ (0.38)		$ (0.35)		$ (1.15)	$ (0.68)
Weighted-average shares outstanding - basic and diluted (in shares)		219,467		205,754		215,070	205,137
Amortization of website development costs and intangible assets included in technology and development		$ 13,100		$ 11,000		$ 24,900	$ 22,000
Technology and Development
Cost of revenue (exclusive of amortization)
Amortization of website development costs and intangible assets included in technology and development	[1]	18,857		14,656		36,041	29,056
Homes
Revenue:
Revenue		454,252		248,924		1,224,125	377,396
Cost of revenue (exclusive of amortization)
Cost of revenue		431,788	[1]	240,732	[1]	1,163,987	363,151
Sales and marketing		47,877		37,409		119,466	58,271
Technology and development		28,918		18,198		61,456	30,479
General and administrative		21,902		17,808		45,323	32,165
Impairment costs						0	0
Integration costs		0		0		0	0
Total costs and expenses		530,485		314,147		1,390,232	484,066
Loss from operations		(76,233)		(65,223)		(166,107)	(106,670)
Other income		0		0		0	0
Interest expense		(3,825)		(5,899)		(11,909)	(9,657)
Loss before income taxes		(80,058)		(71,122)		(178,016)	(116,327)
IMT
Revenue:
Revenue		280,339		323,669		611,005	621,941
Cost of revenue (exclusive of amortization)
Cost of revenue		23,387	[1]	26,059	[1]	47,705	50,310
Sales and marketing		96,026		135,440		216,199	262,094
Technology and development		93,176		94,261		188,204	182,230
General and administrative		53,884		54,671		112,638	125,521
Impairment costs						73,900	0
Integration costs		0		0		0	0
Total costs and expenses		266,473		310,431		638,646	620,155
Loss from operations		13,866		13,238		(27,641)	1,786
Other income		5,300		0		5,300	0
Interest expense		0		0		0	0
Loss before income taxes		19,166		13,238		(22,341)	1,786
Mortgages Segment
Revenue:
Revenue		33,761		26,985		59,043	54,345
Cost of revenue (exclusive of amortization)
Cost of revenue		5,896	[1]	4,430	[1]	11,051	9,108
Sales and marketing		11,695		14,584		24,581	28,655
Technology and development		6,763		7,871		14,115	15,391
General and administrative		9,725		10,360		19,835	20,927
Impairment costs						2,900	0
Integration costs		0		293		0	645
Total costs and expenses		34,079		37,538		72,482	74,726
Loss from operations		(318)		(10,553)		(13,439)	(20,381)
Other income		385		402		587	715
Interest expense		(307)		(287)		(533)	(388)
Loss before income taxes		$ (240)		$ (10,438)		$ (13,385)	$ (20,054)
[1]	Amortization of website development costs and intangible assets included in technology and development of $18,857 and $14,656 for the three months ended June 30, 2020 and 2019, respectively and $36,041 and $29,056 for the six months ended June 30, 2020 and 2019, respectively.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (84,448)	$ (71,977)	$ (247,721)	$ (139,502)
Other comprehensive income (loss):
Unrealized gains (losses) on investments	(2,806)	751	796	1,895
Reclassification adjustment for net investment (gains) losses included in net loss	(62)	0	372	0
Net unrealized gains (losses) on investments	(2,868)	751	1,168	1,895
Currency translation adjustments	107	(52)	17	(94)
Total other comprehensive income (loss)	(2,761)	699	1,185	1,801
Comprehensive loss	$ (87,209)	$ (71,278)	$ (246,536)	$ (137,701)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Class A Common Stock, Class B Common Stock and Class C Capital Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning Balance at Dec. 31, 2018	$ 3,267,179	$ 21	$ 3,939,842	$ (671,779)	$ (905)
Beginning Balance (in shares) at Dec. 31, 2018		203,904,265
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common and capital stock upon exercise of stock options	32,997		32,997
Issuance of common and capital stock upon exercise of stock options (in shares)		1,543,850
Vesting of restricted stock units (in shares)		1,065,607
Shares and value of restricted stock units withheld for tax liability	(3)		(3)
Shares and value of restricted stock units withheld for tax liability (in shares)		(86)
Share-based compensation expense	115,634		115,634
Net loss	(139,502)			(139,502)
Other comprehensive income (loss)	1,801				1,801
Ending Balance at Jun. 30, 2019	3,278,106	$ 21	4,088,470	(811,281)	896
Ending Balance (in shares) at Jun. 30, 2019		206,513,636
Beginning Balance at Mar. 31, 2019	3,283,132	$ 21	4,022,218	(739,304)	197
Beginning Balance (in shares) at Mar. 31, 2019		205,130,332
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common and capital stock upon exercise of stock options	19,433		19,433
Issuance of common and capital stock upon exercise of stock options (in shares)		814,062
Vesting of restricted stock units (in shares)		569,260
Shares and value of restricted stock units withheld for tax liability	(1)		(1)
Shares and value of restricted stock units withheld for tax liability (in shares)		(18)
Share-based compensation expense	46,820		46,820
Net loss	(71,977)			(71,977)
Other comprehensive income (loss)	699				699
Ending Balance at Jun. 30, 2019	3,278,106	$ 21	4,088,470	(811,281)	896
Ending Balance (in shares) at Jun. 30, 2019		206,513,636
Beginning Balance at Dec. 31, 2019	3,435,421	$ 21	4,412,200	(977,140)	340
Beginning Balance (in shares) at Dec. 31, 2019		209,066,855
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common and capital stock upon exercise of stock options	$ 184,985	$ 1	184,984
Issuance of common and capital stock upon exercise of stock options (in shares)	6,324,858	6,324,858
Vesting of restricted stock units (in shares)		1,414,158
Shares and value of restricted stock units withheld for tax liability	$ 0		0
Shares and value of restricted stock units withheld for tax liability (in shares)		(6)
Share-based compensation expense	104,636		104,636
Issuance of Class C capital stock in connection with equity offering, net of issuance costs	411,523	$ 1	411,522
Issuance of Class C capital stock in connection with equity offering, net of issuance costs (in shares)		8,800,000
Equity component of issuance of 2025 Notes, net of issuance costs	154,813		154,813
Partial repurchase of 2021 Notes	(21,784)		(21,784)
Partial repurchase of 2021 Notes (in shares)		753,936
Partial unwind of capped call transactions (in shares)		(317,865)
Net loss	(247,721)			(247,721)
Other comprehensive income (loss)	1,185				1,185
Ending Balance at Jun. 30, 2020	4,023,058	$ 23	5,246,371	(1,224,861)	1,525
Ending Balance (in shares) at Jun. 30, 2020		226,041,936
Beginning Balance at Mar. 31, 2020	3,415,761	$ 22	4,551,866	(1,140,413)	4,286
Beginning Balance (in shares) at Mar. 31, 2020		212,913,139
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common and capital stock upon exercise of stock options	92,783		92,783
Issuance of common and capital stock upon exercise of stock options (in shares)		3,117,483
Vesting of restricted stock units (in shares)		775,249
Shares and value of restricted stock units withheld for tax liability (in shares)		(6)
Share-based compensation expense	57,171		57,171
Issuance of Class C capital stock in connection with equity offering, net of issuance costs	411,523	$ 1	411,522
Issuance of Class C capital stock in connection with equity offering, net of issuance costs (in shares)		8,800,000
Equity component of issuance of 2025 Notes, net of issuance costs	154,813		154,813
Partial repurchase of 2021 Notes	(21,784)		(21,784)
Partial repurchase of 2021 Notes (in shares)		753,936
Partial unwind of capped call transactions (in shares)		(317,865)
Net loss	(84,448)			(84,448)
Other comprehensive income (loss)	(2,761)				(2,761)
Ending Balance at Jun. 30, 2020	$ 4,023,058	$ 23	$ 5,246,371	$ (1,224,861)	$ 1,525
Ending Balance (in shares) at Jun. 30, 2020		226,041,936

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2020USD ($)
Statement of Stockholders' Equity [Abstract]
Capital stock, issuance costs	$ 10,877	$ 10,877
Senior notes, issuance costs	$ 3,279	$ 3,279

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities
Net loss	$ (247,721)	$ (139,502)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	55,199	41,728
Share-based compensation expense	96,146	109,756
Amortization of right of use assets	12,731	10,572
Amortization of contract cost assets	17,070	17,880
Amortization of discount and issuance costs on convertible senior notes maturing in 2021, 2023, 2024, 2025 and 2026	47,746	17,799
Gain on partial extinguishment of 2021 Notes	(6,391)	0
Impairment costs	76,800	0
Deferred income taxes	(8,549)	(2,500)
(Gain) loss on disposal of property and equipment and other assets	(2,658)	3,878
Credit loss expense	1,614	706
Net loss on investment securities	372	0
Accretion of bond discount	(303)	(3,695)
Changes in operating assets and liabilities:
Accounts receivable	(1,487)	(16,884)
Mortgage loans held for sale	(38,514)	(3,244)
Inventory	701,145	(389,994)
Prepaid expenses and other assets	(771)	(2,015)
Lease liabilities	(495)	(11,946)
Contract cost assets	(19,608)	(18,332)
Accounts payable	7,504	1,256
Accrued expenses and other current liabilities	(8,741)	6,952
Accrued compensation and benefits	(3,285)	613
Deferred revenue	4,767	3,000
Other long-term liabilities	10,049	149
Net cash provided by (used in) operating activities	692,620	(373,823)
Investing activities
Proceeds from maturities of investments	701,266	539,312
Proceeds from sales of investments	116,394	0
Purchases of investments	(1,026,233)	(302,891)
Purchases of property and equipment	(54,653)	(29,672)
Purchases of intangible assets	(11,408)	(8,927)
Proceeds from sale of equity investment	10,000	0
Net cash provided by (used in) investing activities	(264,634)	197,822
Financing activities
Proceeds from issuance of 2025 Notes, net of issuance costs	553,282	0
Proceeds from Issuance of Common Stock	411,522	0
Partial extinguishment of 2021 Notes	(194,670)	0
Proceeds from borrowings on credit facilities	43,200	293,099
Repayments of borrowings on credit facilities	(617,506)	0
Net borrowings (repayments) on warehouse lines of credit and repurchase agreement	39,387	(2,961)
Proceeds from exercise of stock options	184,984	32,997
Value of equity awards withheld for tax liability	0	3
Net cash provided by financing activities	420,199	323,138
Net increase in cash, cash equivalents and restricted cash during period	848,185	147,137
Cash, cash equivalents and restricted cash at beginning of period	1,230,909	663,443
Cash, cash equivalents and restricted cash at end of period	2,079,094	810,580
Supplemental disclosures of cash flow information
Cash paid for interest	29,201	16,616
Noncash transactions:
Capitalized share-based compensation	8,490	5,878
Write-off of fully depreciated property and equipment	6,942	9,867
Write-off of fully amortized intangible assets	0	3,311
Property and equipment purchased on account	$ 5,305	$ 2,408

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Organization and Description of Business	Organization and Description of Business Zillow Group, Inc., the largest portfolio of real estate brands on mobile and the web, is building a trusted, on-demand real estate experience. Whether selling, buying, renting or financing, customers can turn to the Zillow family of businesses to find and get into their next home with speed, certainty and ease. In addition to Zillow’s for-sale and rental listings, Zillow Offers buys and sells homes directly in dozens of markets across the country, allowing sellers control over their timeline. Zillow Closing Services offers customers title and escrow services to support a more seamless transaction experience. Zillow Home Loans, our affiliate lender, provides our customers with an easy option to get pre-approved and secure financing for their next home purchase. Other consumer brands include Trulia, StreetEasy, HotPads, Naked Apartments and Out East. In addition, Zillow Group provides a comprehensive suite of marketing software and technology solutions which include Mortech, dotloop, Bridge Interactive and New Home Feed. Zillow, Inc. was incorporated as a Washington corporation in December 2004, and we launched the initial version of our website, Zillow.com, in February 2006. Zillow Group, Inc. was incorporated as a Washington corporation in July 2014 in connection with our acquisition of Trulia, Inc. (“Trulia”). Upon the closing of the Trulia acquisition in February 2015, each of Zillow, Inc. and Trulia became wholly owned subsidiaries of Zillow Group. Certain Significant Risks and Uncertainties We operate in a dynamic industry and, accordingly, can be affected by a variety of factors. For example, we believe that changes in any of the following areas could have a significant negative effect on us in terms of our future financial position, results of operations or cash flows: public health crises, like the COVID-19 pandemic; rates of revenue growth; our ability to manage advertising inventory or pricing; engagement and usage of our products; our investment of resources to pursue strategies that may not prove effective; competition in our market; the stability of the residential real estate market and the impact of interest rate changes; changes in technology, products, markets or services by us or our competitors; addition or loss of significant customers; our ability to maintain or establish relationships with listings and data providers; our ability to obtain or maintain licenses and permits to support our current and future businesses; actual or anticipated changes to our products and services; changes in government regulation affecting our business; outcomes of legal proceedings; natural disasters and catastrophic events; scaling and adaptation of existing technology and network infrastructure; management of our growth; our ability to attract and retain qualified employees and key personnel; our ability to successfully integrate and realize the benefits of our past or future strategic acquisitions or investments; protection of customers’ information and other privacy concerns; protection of our brand and intellectual property; and intellectual property infringement and other claims, among other things.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements include Zillow Group, Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. These condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and accompanying notes included in Zillow Group, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the SEC on February 19, 2020. The condensed consolidated balance sheet as of December 31, 2019, included herein, was derived from the audited financial statements of Zillow Group, Inc. as of that date. The unaudited condensed consolidated interim financial statements, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary to present fairly our financial position as of June 30, 2020, our results of operations, comprehensive loss and shareholders’ equity for the three and six month periods ended June 30, 2020 and 2019, and our cash flows for the six month periods ended June 30, 2020 and 2019. The results of the three and six month periods ended June 30, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any interim period or for any other future year. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. On an ongoing basis, we evaluate our estimates, including those related to the net realizable value of inventory, amortization period and recoverability of contract cost assets, website and software development costs, recoverability of long-lived assets and intangible assets with definite lives, share-based compensation, income taxes, business combinations and the recoverability of goodwill, among others. To the extent there are material differences between these estimates, judgments or assumptions and actual results, our financial statements will be affected. The COVID-19 pandemic has introduced significant additional uncertainty with respect to estimates, judgments and assumptions, which may materially impact the estimates previously listed, among others. Recently Issued Accounting Standards Not Yet Adopted In March 2020, the Financial Accounting Standards Board (“FASB”) issued guidance which provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions that reference the London Inter-Bank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform. This guidance is optional for a limited period of time to ease the potential burden in accounting for, or recognizing the effects of, reference rate reform on financial reporting. This guidance is effective from March 12, 2020 through December 31, 2022. Entities may elect to adopt the amendments for contract modifications as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. We expect to apply some of the expedients and exceptions provided in this guidance to our credit facilities, warehouse line of credit and master repurchase agreement, all of which reference LIBOR in the applicable interest rate. While the goal of the reference rate reform transition is for it to be economically neutral to entities, we have not yet determined the impact the adoption of this guidance will have on our financial position, results of operations or cash flows.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Accounting standards define fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. The standards also establish a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value: • Level 1 — Quoted prices in active markets for identical assets or liabilities. • Level 2 — Assets and liabilities valued based on observable market data for similar instruments, such as quoted prices for similar assets or liabilities. • Level 3 — Unobservable inputs that are supported by little or no market activity; instruments valued based on the best available data, some of which is internally developed, and considers risk premiums that a market participant would require. We applied the following methods and assumptions in estimating our fair value measurements: Cash equivalents — The fair value measurement of money market funds is based on quoted market prices in active markets. The fair value measurement of treasury bills are based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means. Short-term investments — The fair value measurement of our short-term investments is based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means. Restricted cash — Restricted cash consists of cash received from the resale of homes through Zillow Offers which may be used to repay amounts borrowed on our credit facilities (see Note 12) and amounts held in escrow related to funding home purchases in our mortgage origination business. The carrying value of restricted cash approximates fair value due to the short period of time amounts borrowed on the credit facilities are outstanding and amounts are held in escrow. Mortgage loans held for sale — The fair value of mortgage loans held for sale is generally calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics. Interest rate lock commitments — The fair value of interest rate lock commitments (“IRLCs”) is calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics. Expired commitments are excluded from the fair value measurement. We generally only issue IRLCs for products that meet specific purchaser guidelines. Since not all IRLCs will become closed loans, we adjust our fair value measurements for the estimated amount of IRLCs that will not close. This adjustment is effected through the pull-through rate, which represents the probability that an interest rate lock commitment will ultimately result in a closed loan. The pull-through rate is based on estimated changes in market conditions, loan stage and historical borrower behavior. Pull-through rates are directly related to the fair value of IRLCs as an increase in the pull-through rate, in isolation, would result in an increase in the fair value measurement. Conversely, a decrease in the pull-through rate, in isolation, would result in a decrease in the fair value measurement. Changes in the fair value of IRLCs are included within Mortgages revenue in our condensed consolidated statements of operations. The following table presents the range and weighted average pull-through rates used in determining the fair value of IRLCs as of the periods presented: June 30, 2020 December 31, 2019 Range 40% - 100% 56% - 100% Weighted average 70% 78% Forward contracts — The fair value of mandatory loan sales commitments and derivative instruments such as forward sales of mortgage-backed securities that are utilized as economic hedging instruments are calculated by reference to quoted prices for similar assets. The following tables present the balances of assets and liabilities measured at fair value on a recurring basis, by level within the fair value hierarchy, as of the dates presented (in thousands): June 30, 2020 Total Level 1 Level 2 Level 3 Cash equivalents: Money market funds $ 1,784,896 $ 1,784,896 $ — $ — Treasury bills 70,189 — 70,189 — Short-term investments: Treasury bills 963,231 — 963,231 — U.S. government agency securities 465,715 — 465,715 — Corporate notes and bonds 30,213 — 30,213 — Municipal securities 16,538 — 16,538 — Commercial paper 14,972 — 14,972 — Certificates of deposit 498 — 498 — Mortgage origination-related: Mortgage loans held for sale 75,021 — 75,021 — IRLCs 5,091 — — 5,091 Forward contracts - other current liabilities 961 — 961 — Total $ 3,427,325 $ 1,784,896 $ 1,637,338 $ 5,091 December 31, 2019 Total Level 1 Level 2 Cash equivalents: Money market funds $ 872,431 $ 872,431 $ — U.S. government agency securities 35,009 — 35,009 Commercial paper 31,113 — 31,113 Treasury bills 6,441 — 6,441 Corporate notes and bonds 1,065 — 1,065 Certificates of deposit 249 — 249 Short-term investments: U.S. government agency securities 862,154 — 862,154 Corporate notes and bonds 159,431 — 159,431 Commercial paper 150,267 — 150,267 Treasury bills 80,003 — 80,003 Municipal securities 27,889 — 27,889 Certificates of deposit 1,245 — 1,245 Mortgage origination-related: Mortgage loans held for sale 36,507 — 36,507 IRLCs 937 — 937 Forward contracts - other current assets 7 — 7 Forward contracts - other current liabilities (60) — (60) Total $ 2,264,688 $ 872,431 $ 1,392,257 The following table presents the changes in our IRLCs during the three and six month periods ended June 30, 2020 (in thousands): Three Months Ended Six Months Ended Balance, beginning of the period $ 2,225 $ 937 Issuances 10,142 15,507 Transfers (8,586) (13,142) Fair value changes recognized in earnings 1,310 1,789 Balance, end of period $ 5,091 $ 5,091 (1) Beginning balance represents transfers of IRLCs from Level 2 to Level 3 within the fair value hierarchy as of January 1, 2020. At June 30, 2020, the notional amounts of the hedging instruments related to our mortgage loans held for sale were $168.9 million and $214.9 million for our IRLCs and forward contracts, respectively. At December 31, 2019, the notional amounts of the hedging instruments related to our mortgage loans held for sale were $34.3 million and $64.7 million for our IRLCs and forward contracts, respectively. We do not have the right to offset our forward contract derivative positions. See Note 12 for the carrying amount and estimated fair value of our convertible senior notes.

Cash and Cash Equivalents, Shor

Cash and Cash Equivalents, Short-term Investments and Restricted Cash	6 Months Ended
	Jun. 30, 2020
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents, Short-term Investments and Restricted Cash	Cash and Cash Equivalents, Short-term Investments and Restricted Cash The following tables present the amortized cost, gross unrealized gains and losses and estimated fair market value of our cash and cash equivalents, available-for-sale investments and restricted cash as of the dates presented (in thousands): June 30, 2020 Amortized Gross Gross Estimated Cash $ 190,389 $ — $ — $ 190,389 Cash equivalents: Money market funds 1,784,896 — — 1,784,896 Treasury bills 70,189 — — 70,189 Short-term investments: Treasury bills 963,200 41 (10) 963,231 U.S. government agency securities 463,806 1,909 — 465,715 Corporate notes and bonds 30,094 119 — 30,213 Municipal securities 16,519 19 — 16,538 Commercial paper 14,972 — — 14,972 Certificates of deposit 498 — — 498 Restricted cash 33,620 — — 33,620 Total $ 3,568,183 $ 2,088 $ (10) $ 3,570,261 December 31, 2019 Amortized Gross Gross Estimated Cash $ 194,955 $ — $ — $ 194,955 Cash equivalents: Money market funds 872,431 — — 872,431 U.S. government agency securities 35,011 — (2) 35,009 Commercial paper 31,113 — — 31,113 Treasury bills 6,441 — — 6,441 Corporate notes and bonds 1,065 — — 1,065 Certificates of deposit 249 — — 249 Short-term investments: U.S. government agency securities 861,862 365 (73) 862,154 Corporate notes and bonds 159,382 91 (42) 159,431 Commercial paper 150,267 — — 150,267 Treasury bills 79,989 14 — 80,003 Municipal securities 27,836 56 (3) 27,889 Certificates of deposit 1,245 — — 1,245 Restricted cash 89,646 — — 89,646 Total $ 2,511,492 $ 526 $ (120) $ 2,511,898 All available-for-sale investments as of June 30, 2020 have a contractual maturity date of one year or less.

Accounts Receivable, net

Accounts Receivable, net	6 Months Ended
	Jun. 30, 2020
Receivables [Abstract]
Accounts Receivable, net	Accounts Receivable, net The following table presents the changes in the allowance for doubtful accounts for the six months ended June 30, 2020 (in thousands): Balance as of January 1, 2020 $ 4,522 Credit loss expense 1,614 Less: write-offs, net of recoveries and other adjustments (3,854) Balance as of June 30, 2020 $ 2,282

Inventory

Inventory	6 Months Ended
	Jun. 30, 2020
Inventory Disclosure [Abstract]
Inventory	Inventory The following table presents the components of inventory, net of applicable lower of cost or net realizable value adjustments, as of the dates presented (in thousands): June 30, 2020 December 31, 2019 Work-in-process $ 12,164 $ 152,171 Finished goods 123,237 684,456 Inventory $ 135,401 $ 836,627

Contract Cost Assets

Contract Cost Assets	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Contract Cost Assets	Contract Cost AssetsDuring the three and six month periods ended June 30, 2020 and 2019, we did not incur any impairment losses to our contract cost assets. We recorded amortization expense related to contract cost assets of $8.7 million and $9.2 million during the three months ended June 30, 2020 and 2019, respectively, and $17.1 million and $17.9 million during the six months ended June 30, 2020 and 2019, respectively.Deferred Revenue The following tables present the changes in deferred revenue for the periods presented (in thousands): Three Months Ended Balance as of April 1, 2020 $ 35,347 Deferral of revenue 222,895 Less: Revenue recognized (213,728) Balance as of June 30, 2020 $ 44,514 Six Months Ended Balance as of January 1, 2020 $ 39,747 Deferral of revenue 476,624 Less: Revenue recognized (471,857) Balance as of June 30, 2020 $ 44,514 During the three months ended June 30, 2020 we recognized as revenue a total of $33.8 million pertaining to amounts that were recorded in deferred revenue as of April 1, 2020. During the six months ended June 30, 2020 we recognized as revenue a total of $36.6 million pertaining to amounts that were recorded in deferred revenue as of January 1, 2020.

Property and Equipment, net

Property and Equipment, net	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net The following table presents the detail of property and equipment as of the dates presented (in thousands): June 30, 2020 December 31, 2019 Website development costs $ 157,468 $ 149,648 Leasehold improvements 107,139 81,981 Construction-in-progress 51,482 45,337 Office equipment, furniture and fixtures 42,236 36,582 Computer equipment 31,801 31,942 Property and equipment 390,126 345,490 Less: accumulated amortization and depreciation (194,379) (175,001) Property and equipment, net $ 195,747 $ 170,489 We recorded depreciation expense related to property and equipment (other than website development costs) of $7.1 million and $6.4 million during the three months ended June 30, 2020 and 2019, respectively, and $18.9 million and $12.4 million during the six months ended June 30, 2020 and 2019, respectively. We capitalized $15.4 million and $10.3 million in website development costs during the three months ended June 30, 2020 and 2019, respectively, and $27.9 million and $20.3 million during the six months ended June 30, 2020 and 2019, respectively. Amortization expense for website development costs included in technology and development expenses was $6.0 million and $3.6 million during the three months ended June 30, 2020 and 2019, respectively, and $11.4 million and $7.0 million during the six months ended June 30, 2020 and 2019, respectively.

Equity Investment

Equity Investment	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment	Equity InvestmentIn October 2016, we purchased a 10% equity interest in a privately held variable interest entity within the real estate industry for $10.0 million. In March 2020, we recognized a non-cash impairment charge of $5.3 million related to this investment. The impairment charge is included in Impairment costs within our IMT segment for the six months ended June 30, 2020. In connection with our assessment of the investment for impairment indicators as a result of COVID-19’s significant adverse impact on the real estate industry, we identified factors that led us to conclude that the investment was impaired and the fair value of the investment was less than the carrying value. The most significant of such factors related to the future expected cash flows of the investee. Accordingly, we performed an analysis to determine the fair value of the investment and concluded that our best estimate of its fair value was $4.7 million. In June 2020, we sold our 10% equity interest for $10.0 million in cash. We recorded a gain on the sale of the investment of $5.3 million for the three and six month periods ended June 30, 2020 which is classified within Other income in our condensed consolidated statements of operations.

Intangible Assets, net

Intangible Assets, net	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, net	Intangible Assets, net The following tables present the detail of intangible assets subject to amortization as of the dates presented (in thousands): June 30, 2020 Cost Accumulated Net Trade names and trademarks $ 36,500 $ (1,274) $ 35,226 Customer relationships 102,600 (81,372) 21,228 Developed technology 107,200 (87,340) 19,860 Software 40,744 (25,031) 15,713 Intangibles-in-progress 10,054 — 10,054 Purchased content 50,552 (45,726) 4,826 Lender licenses 400 (317) 83 Total $ 348,050 $ (241,060) $ 106,990 December 31, 2019 Cost Accumulated Net Customer relationships $ 102,600 $ (73,770) $ 28,830 Developed technology 107,200 (81,383) 25,817 Software 35,527 (20,843) 14,684 Purchased content 47,298 (40,636) 6,662 Intangibles-in-progress 6,391 — 6,391 Lender licenses 400 (217) 183 Total $ 299,416 $ (216,849) $ 82,567 Amortization expense recorded for intangible assets for the three months ended June 30, 2020 and 2019 was $13.1 million and $11.0 million, respectively, and $24.9 million and $22.0 million for the six months ended June 30, 2020 and 2019, respectively. These amounts are included in technology and development expenses.

Deferred Revenue

Deferred Revenue	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Deferred Revenue	Contract Cost AssetsDuring the three and six month periods ended June 30, 2020 and 2019, we did not incur any impairment losses to our contract cost assets. We recorded amortization expense related to contract cost assets of $8.7 million and $9.2 million during the three months ended June 30, 2020 and 2019, respectively, and $17.1 million and $17.9 million during the six months ended June 30, 2020 and 2019, respectively.Deferred Revenue The following tables present the changes in deferred revenue for the periods presented (in thousands): Three Months Ended Balance as of April 1, 2020 $ 35,347 Deferral of revenue 222,895 Less: Revenue recognized (213,728) Balance as of June 30, 2020 $ 44,514 Six Months Ended Balance as of January 1, 2020 $ 39,747 Deferral of revenue 476,624 Less: Revenue recognized (471,857) Balance as of June 30, 2020 $ 44,514 During the three months ended June 30, 2020 we recognized as revenue a total of $33.8 million pertaining to amounts that were recorded in deferred revenue as of April 1, 2020. During the six months ended June 30, 2020 we recognized as revenue a total of $36.6 million pertaining to amounts that were recorded in deferred revenue as of January 1, 2020.

Debt

Debt	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Debt	Debt The following table presents the carrying values of Zillow Group’s debt as of the periods presented (in thousands): June 30, 2020 December 31, 2019 Homes Segment Credit facilities: Goldman Sachs Bank USA $ 19,632 $ 39,244 Citibank, N.A. 33,037 296,369 Credit Suisse AG, Cayman Islands 64,549 355,911 Total Homes Segment debt 117,218 691,524 Mortgages Segment Repurchase agreement: Citibank, N.A. 33,918 394 Warehouse line of credit: Comerica Bank 35,896 30,033 Total Mortgages Segment debt 69,814 30,427 Convertible Senior Notes 1.375% convertible senior notes due 2026 337,171 327,187 2.75% convertible senior notes due 2025 401,786 — 0.75% convertible senior notes due 2024 507,039 490,538 1.50% convertible senior notes due 2023 318,348 310,175 2.00% convertible senior notes due 2021 245,997 415,502 2.75% convertible senior notes due 2020 9,637 9,637 Total convertible senior notes 1,819,978 1,553,039 Total $ 2,007,010 $ 2,274,990 Homes Segment To provide capital for Zillow Offers, we utilize credit facilities that are classified as current liabilities in our condensed consolidated balance sheets. We classify these credit facilities as current liabilities as amounts drawn to purchase homes are typically repaid as homes are sold, which we expect to be within one year. The following table summarizes certain details related to our credit facilities (in thousands, except interest rates): Lender Final Maturity Date Maximum Borrowing Capacity Weighted Average Interest Rate Goldman Sachs Bank USA April 20, 2022 $ 500,000 3.91 % Citibank, N.A. January 31, 2022 500,000 4.69 % Credit Suisse AG, Cayman Islands July 31, 2021 500,000 4.62 % Total $ 1,500,000 Undrawn amounts available under the credit facilities included in the table above are not committed, meaning the applicable lender is not committed to, but may in its discretion, advance loan funds in excess of the outstanding borrowings. The final maturity dates are inclusive of extensions which are subject to agreement by the respective lender. Zillow Group formed certain special purpose entities (each, an “SPE”) to purchase and sell residential properties through Zillow Offers. Each SPE is a wholly owned subsidiary of Zillow Group and a separate legal entity, and neither the assets nor credit of any such SPE are available to satisfy the debts and other obligations of any affiliate or other entity. The credit facilities are secured by the assets and equity of one or more SPEs. These SPEs are variable interest entities and Zillow Group is the primary beneficiary as it has the power to control the activities that most significantly impact the SPEs’ economic performance and the obligation to absorb losses of the SPEs or the right to receive benefits from the SPEs that could potentially be significant to the SPEs. The SPEs are consolidated within Zillow Group’s condensed consolidated financial statements. The collective inventory and credit facility borrowings of the SPEs were $135.4 million and $117.2 million, respectively, as of June 30, 2020, and $836.6 million and $691.5 million, respectively, as of December 31, 2019. Outstanding amounts drawn under each credit facility are required to be repaid on the facility maturity date or earlier if accelerated due to an event of default. Further, each SPE is required to repay any resulting shortfall if the value of the eligible properties owned by such SPE falls below a certain percentage of the principal amount outstanding under the applicable credit facility. Continued inclusion of properties in each credit facility is subject to various eligibility criteria. For example, aging criteria limit the inclusion in the borrowing base of properties owned longer than a specified number of days, and properties owned for longer than one year are generally ineligible. The stated interest rate on our credit facilities is one-month LIBOR plus an applicable margin as defined in the respective credit agreements. Our credit facilities include customary representations and warranties, provisions regarding events of default and covenants. The terms of these credit facilities and related financing documents require Zillow Group and certain of its subsidiaries, as applicable, to comply with a number of customary financial and other covenants, such as maintaining certain levels of liquidity, tangible net worth and leverage ratios. As of June 30, 2020, Zillow Group was in compliance with all financial covenants and no event of default had occurred. Except for certain limited circumstances, the credit facilities are non-recourse to Zillow Group. Our credit facilities require that we establish, maintain and in certain circumstances that Zillow Group fund specified reserve accounts. These reserve accounts include, but are not limited to, interest reserves, insurance reserves, tax reserves, renovation cost reserves and reserves for specially permitted liens. Amounts funded to these reserve accounts and the collection accounts have been classified within our condensed consolidated balance sheets as restricted cash. Mortgages Segment To provide capital for Zillow Home Loans, we utilize a warehouse line of credit and a master repurchase agreement which are classified as current liabilities in our condensed consolidated balance sheets. The warehouse line of credit and repurchase agreement provide short-term financing between the issuance of a mortgage loan and when Zillow Home Loans sells the loan to an investor. The following table summarizes certain details related to our warehouse line of credit and repurchase agreement (in thousands, except interest rates): Lender Maturity Date Maximum Borrowing Capacity Weighted Average Interest Rate Citibank, N.A. October 27, 2020 $ 75,000 1.88 % Comerica Bank June 26, 2021 50,000 2.81 % Total $ 125,000 On June 27, 2020, Zillow Home Loans amended its warehouse line of credit with Comerica Bank previously maturing on June 27, 2020 to extend the term of the original agreement for one year through June 26, 2021. The warehouse line of credit with Comerica Bank is committed. The repurchase agreement with Citibank, N.A. includes a committed amount of $25.0 million. As of June 30, 2020 and December 31, 2019, $33.9 million and $0.4 million, respectively, in mortgage loans held for sale were pledged as collateral under the facility. Borrowings on the warehouse line of credit and repurchase agreement bear interest at the one-month LIBOR plus an applicable margin, and in certain cases include a LIBOR floor, as defined in the governing agreements, and are secured by residential mortgage loans held for sale. The repurchase agreement contains margin call provisions that provide Citibank, N.A. with certain rights in the event of a decline in the market value of the assets purchased under the repurchase agreement. The warehouse line of credit and repurchase agreement include customary representations and warranties, covenants and provisions regarding events of default. As of June 30, 2020, Zillow Home Loans was in compliance with all financial covenants and no event of default had occurred. The warehouse line of credit and repurchase agreement are recourse to Zillow Home Loans, and have no recourse to Zillow Group or any of its other subsidiaries. For additional details related to our warehouse line of credit and repurchase agreement, see Note 15 in the Notes to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019. Convertible Senior Notes The following tables summarize certain details related to our outstanding convertible senior notes as of the periods presented (in thousands, except interest rates): June 30, 2020 December 31, 2019 Maturity Date Aggregate Principal Amount Stated Interest Rate Effective Interest Rate First Interest Payment Date Semi-Annual Interest Payment Dates Unamortized Debt Discount and Debt Issuance Costs Fair Value Unamortized Debt Discount and Debt Issuance Costs Fair Value September 1, 2026 $ 500,000 1.375 % 8.10 % March 1, 2020 March 1; September 1 $ 162,829 $ 705,000 $ 172,813 $ 597,380 May 15, 2025 565,000 2.75 % 10.32 % November 15, 2020 May 15; November 15 163,214 659,756 — — September 1, 2024 673,000 0.75 % 7.68 % March 1, 2020 March 1; September 1 165,961 957,659 182,462 819,378 July 1, 2023 373,750 1.50 % 6.99 % January 1, 2019 January 1; July 1 55,402 388,113 63,575 356,464 December 1, 2021 265,330 2.00 % 7.43 % June 1, 2017 June 1; December 1 19,333 326,688 44,498 514,312 December 15, 2020 9,637 2.75 % N/A N/A June 15; December 15 — 16,842 — 16,842 Total $ 2,386,717 $ 566,739 $ 3,054,058 $ 463,348 $ 2,304,376 Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Maturity Date Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense September 1, 2026 $ 1,719 $ 4,922 $ 120 $ 6,761 $ — $ — $ — $ — May 15, 2025 2,007 3,148 168 5,323 — — — — September 1, 2024 1,262 8,095 278 9,635 — — — — July 1, 2023 1,402 3,749 366 5,517 1,402 3,496 342 5,240 December 1, 2021 1,803 3,945 408 6,156 2,300 4,677 484 7,461 December 15, 2020 66 — — 66 66 — — 66 Total $ 8,259 $ 23,859 $ 1,340 $ 33,458 $ 3,768 $ 8,173 $ 826 $ 12,767 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Maturity Date Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense September 1, 2026 $ 3,438 $ 9,746 $ 238 $ 13,422 $ — $ — $ — $ — May 15, 2025 2,007 3,148 168 5,323 — — — — September 1, 2024 2,510 15,956 545 19,011 — — — — July 1, 2023 2,804 7,446 727 10,977 2,804 6,933 678 10,415 December 1, 2021 4,103 8,856 916 13,875 4,600 9,268 959 14,827 December 15, 2020 132 — — 132 132 — — 132 Total $ 14,994 $ 45,152 $ 2,594 $ 62,740 $ 7,536 $ 16,201 $ 1,637 $ 25,374 The convertible notes are senior unsecured obligations. The convertible senior notes maturing in 2026, 2025, 2024, 2023 and 2021 (the “Notes”) are classified as long-term debt based on their contractual maturity dates in our condensed consolidated balance sheets. The convertible senior notes maturing in 2020 are classified within current liabilities. For more than 20 trading days during the 30 consecutive trading days ended June 30, 2020, the last reported sale price of our Class C capital stock exceeded 130% of the conversion price of the convertible senior notes due in 2024 and 2026 (the “2024 Notes” and “2026 Notes”, respectively). Accordingly, the 2024 Notes and 2026 Notes became convertible at the option of the holders from July 1 through September 30, 2020. The convertible senior notes maturing in 2025, 2023 and 2021 are not redeemable or convertible as of June 30, 2020. The convertible senior notes maturing in 2020 are convertible, at the option of the holder, and redeemable, at our option, as of June 30, 2020. Interest on the convertible notes is paid semi-annually in arrears. The estimated fair value of the convertible senior notes was determined through consideration of quoted market prices. The fair value is classified as Level 3 due to the limited trading activity for each of the convertible senior notes. The Notes are convertible into cash, shares of Class C capital stock or a combination thereof, at our election, and may be settled as described below. The Notes will mature on their respective maturity date, unless earlier repurchased, redeemed or converted in accordance with their terms. The following table summarizes the conversion and redemption options with respect to the Notes: Maturity Date Early Conversion Date Conversion Rate Conversion Price Optional Redemption Date September 1, 2026 March 1, 2026 22.9830 $ 43.51 September 5, 2023 May 15, 2025 November 15, 2024 14.8810 67.20 May 22, 2023 September 1, 2024 March 1, 2024 22.9830 43.51 September 5, 2022 July 1, 2023 April 1, 2023 12.7592 78.37 July 6, 2021 December 1, 2021 September 1, 2021 19.0985 52.36 December 6, 2019 The following table summarizes certain details related to the capped call confirmations with respect to certain of the convertible senior notes: Maturity Date Initial Cap Price Cap Price Premium September 1, 2026 $ 80.5750 150 % September 1, 2024 72.5175 125 % July 1, 2023 105.45 85 % December 1, 2021 69.19 85 % On May 15, 2020, we issued $500.0 million aggregate principal amount of 2.75% Convertible Senior Notes due 2025 (the “Initial 2025 Notes”) and on May 19, 2020 we issued $65.0 million aggregate principal amount of 2.75% Convertible Senior Notes due 2025 (the “Additional Notes” and, together with the Initial 2025 Notes, the “2025 Notes”). The Additional Notes were sold pursuant to the underwriters’ option to purchase additional 2025 Notes granted in connection with the offering of the Initial 2025 Notes. The net proceeds from the issuance of the 2025 Notes were approximately $553.3 million, after deducting underwriting discounts and commissions and offering expenses paid by Zillow Group. We used a portion of the net proceeds from the issuance of the 2025 Notes to repurchase $194.7 million aggregate principal of the convertible senior notes due 2021 (the “2021 Notes”) in privately negotiated transactions. The 2021 Notes were repurchased for $194.7 million in cash and 753,936 shares of Class C capital stock for an aggregate purchase price of $230.9 million. The repurchase of the 2021 Notes was accounted for as a debt extinguishment. We allocated $172.9 million of the repurchase price to the liability component based on the fair value of the liability component immediately prior to settlement. The fair value of the liability component was calculated using a discounted cash flow analysis with a market interest rate of a similar liability that does not have an associated convertible feature. The remaining consideration of $58.0 million was allocated to the equity component. As a result, we recognized a $179.3 million reduction to long-term debt representing the carrying value of the liability component as of the date of the partial repurchase of the 2021 Notes, a $58.0 million reduction to additional paid-in capital representing the equity component of the partially repurchased 2021 Notes and a $6.4 million gain on partial extinguishment of 2021 Notes representing the excess of the carrying value of the liability component over the fair value of the liability component of the repurchased 2021 Notes. In connection with the repurchase of a portion of the 2021 Notes, we partially terminated the capped call transactions entered into in connection with the issuance of the 2021 Notes for an amount corresponding to the aggregate principal amount of the 2021 Notes that were repurchased. As a result of the partial settlement of the capped call transactions, we received 317,865 shares of our Class C capital stock equal to a value of approximately $14.8 million based on the trading price of our Class C capital stock at the time of the unwind. Under applicable Washington State law, the acquisition of a corporation’s own shares is not disclosed separately as treasury stock in the financial statements and such shares are treated as authorized but unissued shares. We record acquisitions of our shares of capital stock as a reduction to capital stock at the par value of the shares reacquired, then to additional paid-in capital until it is depleted to a nominal amount, with any further excess recorded to retained earnings. We recorded an offsetting increase to additional paid-in capital for the partial unwind of the capped call transactions. We intend to use the remainder of the net proceeds from the 2025 Notes for general corporate purposes, which may include general and administrative matters and capital expenditures. Prior to the close of business on the business day immediately preceding November 15, 2024, the 2025 Notes are convertible at the option of the holders of the 2025 Notes only under certain conditions. On or after November 15, 2024, until the close of business on the second scheduled trading day immediately preceding May 15, 2025, holders of the 2025 Notes may convert the 2025 Notes at their option at the conversion rate then in effect, irrespective of these conditions. Zillow Group will settle conversions of the 2025 Notes by paying or delivering, as the case may be, cash, shares of its Class C capital stock, or a combination of cash and shares of its Class C capital stock, at its election. The conversion rate will initially be 14.8810 shares of Class C capital stock per $1,000 principal amount of 2025 Notes (equivalent to an initial conversion price of approximately $67.20 per share of Class C capital stock). The conversion rate and the corresponding initial conversion price are subject to customary adjustments upon the occurrence of certain events. Zillow Group may redeem for cash all or part of the 2025 Notes, at its option, on or after May 22, 2023, under certain circumstances, at a redemption price equal to 100% of the principal amount of the 2025 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date (as defined in the indenture governing the 2025 Notes, the “Indenture”). We may not redeem the 2025 Notes prior to May 22, 2023. We may redeem, for cash, all or any portion of the 2025 Notes, at our option, on or after May 22, 2023 if the last reported sale price per share of our Class C capital stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period. The conversion option does not meet the criteria for separate accounting as a derivative as it is indexed to our own stock. If Zillow Group undergoes a fundamental change (as defined in the Indenture), holders of the 2025 Notes may require us to repurchase for cash all or part of their 2025 Notes at a repurchase price equal to 100% of the principal amount of the 2025 Notes to be purchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date (as defined in the Indenture). In addition, if certain fundamental changes occur or if Zillow Group delivers a notice of redemption, we may be required, in certain circumstances, to increase the conversion rate for any 2025 Notes converted in connection with such fundamental changes or notice of redemption by a specified number of shares of our Class C capital stock. Certain events are also considered “Events of Default,” which may result in the acceleration of the maturity of the 2025 Notes, as described in the Indenture. There are no financial covenants associated with the 2025 Notes. In accounting for the issuance of the 2025 Notes, we separated the 2025 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The carrying amount of the equity component, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the 2025 Notes. The difference between the principal amount of the 2025 Notes and the liability component represents the debt discount, which is recorded as a direct deduction from the related debt liability in the condensed consolidated balance sheet and amortized to interest expense using the effective interest method over the term of the 2025 Notes. The equity component of the 2025 Notes of approximately $154.8 million, net of issuance costs of $3.3 million, is included in additional paid-in capital in the condensed consolidated balance sheet and is not remeasured as long as it continues to meet the conditions for equity classification. For additional details related to our convertible senior notes, see Note 15 in the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We are subject to federal and state income taxes in the United States and federal and provincial income taxes in Canada. As of June 30, 2020 and December 31, 2019, we have provided a valuation allowance against our net deferred tax assets that we believe, based on the weight of available evidence, are not more likely than not to be realized. Therefore, no material current tax liability or expense has been recorded in the condensed consolidated financial statements. We have accumulated federal tax losses of approximately $1,137.6 million as of December 31, 2019, which are available to reduce future taxable income. We have accumulated state tax losses of approximately $34.3 million (tax effected) as of December 31, 2019. We recorded income tax expense of $0.7 million for the three months ended June 30, 2020 and an income tax benefit of $8.5 million for the six months ended June 30, 2020. The income tax benefit for the six months ended June 30, 2020 was primarily a result of a $9.7 million income tax benefit related to the $71.5 million non-cash impairment we recorded during the three months ended March 31, 2020 related to the Trulia trade names and trademarks intangible asset. For additional information about the non-cash impairment, see Note 10 to our condensed consolidated financial statements. This income tax benefit was partially offset by an immaterial amount of state income tax expense recorded for the six months ended June 30, 2020.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity Preferred Stock Our board of directors has the authority to fix and determine and to amend the number of shares of any series of preferred stock that is wholly unissued or to be established and to fix and determine and to amend the designation, preferences, voting powers and limitations, and the relative, participating, optional or other rights, of any series of shares of preferred stock that is wholly unissued or to be established, subject in each case to certain approval rights of holders of our outstanding Class B common stock. There was no preferred stock issued and outstanding as of June 30, 2020 or December 31, 2019. Common and Capital Stock Our Class A common stock has no preferences or privileges and is not redeemable. Holders of Class A common stock are entitled to one vote for each share. Our Class B common stock has no preferences or privileges and is not redeemable. At any time after the date of issuance, each share of Class B common stock, at the option of the holder, may be converted into one share of Class A common stock, or automatically converted into Class A common stock upon the affirmative vote by or written consent of holders of a majority of the shares of the Class B common stock. Holders of Class B common stock are entitled to 10 votes for each share. Our Class C capital stock has no preferences or privileges, is not redeemable and, except in limited circumstances, is non-voting. On May 15, 2020, Zillow Group issued and sold 8,000,000 shares of Class C capital stock, and on May 19, 2020, issued and sold an additional 800,000 shares of Class C capital stock pursuant to the exercise of the underwriters’ option to purchase additional shares. The 8,800,000 shares of Class C capital stock were issued and sold at a public offering price of $48.00 per share. We received net proceeds of $411.5 million after deducting underwriting discounts and commissions and offering expenses paid by us. In connection with the partial repurchase of the 2021 Notes, we issued 753,936 shares of Class C capital stock at a price of $48.00 per share with a total value of $36.2 million to settle the conversion spread for the notes repurchased. Additionally, we unwound a portion of the capped call transactions related to the 2021 Notes whereby we received 317,865 shares of our Class C capital stock equal to a value of approximately $14.8 million based on the trading price of our Class C capital stock at the time of the unwind. See Note 12 for further discussion of the partial repurchase of the 2021 Notes and the corresponding capped call unwind.

Share-Based Awards

Share-Based Awards	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Share-Based Awards	Share-Based Awards Zillow Group, Inc. 2020 Incentive Plan On June 9, 2020, the Zillow Group, Inc. 2020 Incentive Plan (the “2020 Plan”) became effective, which replaces the Zillow Group, Inc. Amended and Restated 2011 Incentive Plan (the “2011 Plan”). 12,400,000 shares of Class C capital stock are authorized and available for issuance under the 2020 Plan. In addition, shares previously available for new grants under the 2011 Plan as of June 9, 2020 and shares subject to outstanding awards under the 2011 Plan as of June 9, 2020 that on or after that date cease to be subject to such awards (other than by reason of exercise or settlement of the awards in vested or nonforfeitable shares) are also available for issuance under the 2020 Plan. The number of shares authorized under the 2020 Plan will be increased on the first day of each calendar year, beginning January 1, 2021 and ending on (and including) January 1, 2030, by an amount equal to the lesser of (a) 5% of our outstanding Class A common stock, Class B common stock and Class C capital stock on a fully diluted basis as of the end of the immediately preceding calendar year and (b) a number of shares determined by our board of directors. The 2020 Plan is administered by the compensation committee of the board of directors. Under the terms of the 2020 Plan, the compensation committee may grant equity awards, including incentive stock options, nonqualified stock options, restricted stock, restricted stock units, restricted units, stock appreciation rights, performance shares or performance units to employees, officers, directors, consultants, agents, advisors and independent contractors of Zillow Group and its subsidiaries. The board of directors has also authorized certain senior executive officers to grant equity awards under the 2020 Plan, within limits prescribed by our board of directors. The 2020 Plan provides that in the event of a stock dividend, stock split or similar event, the maximum number and kind of securities available for issuance under the plan will be proportionally adjusted. Options under the 2020 Plan are granted with an exercise price per share not less than 100% of the fair market value of our Class C capital stock on the grant date, with the exception of substituted option awards granted in connection with acquisitions, and are exercisable at such times and under such conditions as determined by the compensation committee. Any portion of an option that is not vested and exercisable on the date of a participant’s termination of service expires on such date. Employees generally forfeit their rights to exercise vested options 3 months following their termination of employment or 12 months following termination by reason of death, disability or retirement. Options granted under the 2020 Plan expire no later than ten years from the grant date and typically vest either 25% after 12 months and quarterly thereafter over the next three years or quarterly over a period of four years. Restricted stock units granted under the 2020 Plan typically vest either 25% after 12 months and quarterly thereafter over the next three years or quarterly over a period of four years. Any portion of a restricted stock unit that is not vested on the date of a participant’s termination of service expires on such date. Options and restricted stock units that remain outstanding under the 2011 Plan have vesting and exercisability terms consistent with those described above for awards granted under the 2020 Plan. Option Awards The following table summarizes option award activity for the six months ended June 30, 2020: Number Weighted- Weighted- Aggregate Outstanding at January 1, 2020 29,634,296 $ 35.95 6.28 $ 331,107 Granted 4,833,605 49.24 Exercised (6,324,858) 29.25 Forfeited or cancelled (674,462) 40.76 Outstanding at June 30, 2020 27,468,581 39.71 6.74 493,801 Vested and exercisable at June 30, 2020 14,708,916 35.84 4.96 320,951 The fair value of options granted is estimated at the date of grant using the Black-Scholes-Merton option-pricing model, assuming no dividends and with the following assumptions for the periods presented: Three Months Ended Six Months Ended 2020 2019 2020 2019 Expected volatility 51% 45% 45%-51% 45%-47% Expected dividend yield — — — — Risk-free interest rate 0.33% 2.00% 0.33%-0.93% 2.00%-2.53% Weighted-average expected life 5.00 years 5.00 years 5.00-5.50 years 4.75-5.25 years Weighted-average fair value of options granted $20.21 $16.96 $20.69 $16.79 As of June 30, 2020, there was a total of $218.2 million in unrecognized compensation cost related to unvested stock options. Restricted Stock Units The following table summarizes activity for restricted stock units for the six months ended June 30, 2020: Restricted Weighted- Unvested outstanding at January 1, 2020 7,052,767 $ 40.01 Granted 3,665,016 49.30 Vested (1,414,158) 40.65 Forfeited (513,401) 41.62 Unvested outstanding at June 30, 2020 8,790,224 43.69 As of June 30, 2020, there was a total of $356.6 million in unrecognized compensation cost related to unvested restricted stock units. Share-Based Compensation Expense The following table presents the effects of share-based compensation expense in our condensed consolidated statements of operations during the periods presented (in thousands): Three Months Ended Six Months Ended 2020 2019 2020 2019 Cost of revenue $ 1,119 $ 936 $ 2,292 $ 1,816 Sales and marketing 9,116 6,801 16,109 12,451 Technology and development 21,666 18,399 40,583 33,908 General and administrative 20,450 17,496 37,162 61,581 Total $ 52,351 $ 43,632 $ 96,146 $ 109,756 On February 21, 2019, Zillow Group announced the appointment of Richard N. Barton as Zillow Group’s Chief Executive Officer, effective February 21, 2019. Mr. Barton succeeds Spencer Rascoff, who served as Zillow Group’s Chief Executive Officer since 2010. In connection with Mr. Rascoff’s resignation as Chief Executive Officer, Zillow Group entered into an Executive Departure Agreement and Release (the “Agreement”) with Mr. Rascoff. Pursuant to the Agreement, Mr. Rascoff received, among other things, a change in the exercise period of his vested stock options outstanding as well as accelerated vesting of outstanding stock options, which have been accounted for as equity modifications. We recorded $26.4 million of share-based compensation expense associated with the modifications during the six months ended June 30, 2019. For additional details, see Note 18 in the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share For the periods presented, the following Class A common stock and Class C capital stock equivalents were excluded from the calculations of diluted net loss per share because their effect would have been antidilutive (in thousands): Three Months Ended Six Months Ended 2020 2019 2020 2019 Weighted-average Class A common stock and Class C capital stock option awards outstanding 25,202 19,502 22,649 19,656 Weighted-average Class A common stock and Class C capital stock restricted stock units outstanding 9,086 7,230 8,354 6,548 Class A common stock issuable upon conversion of the convertible notes maturing in 2020 400 411 400 411 Class C capital stock issuable upon conversion of the convertible notes maturing in 2021, 2024 and 2026 7,232 — 7,316 — Total Class A common stock and Class C capital stock equivalents 41,920 27,143 38,719 26,615 Since we expect to settle the principal amount of the outstanding Notes in cash, we use the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread for each of the notes has a dilutive impact on diluted net income per share when the market price of the Company’s Class C capital stock at the end of the period exceeds the conversion price per share. The following table presents the conversion spread and conversion price per share of Class C capital stock for each of the convertible senior notes (in thousands, except per share amounts): Maturity Date Conversion Spread Conversion Price per Share September 1, 2026 11,492 $ 43.51 May 15, 2025 8,408 67.20 September 1, 2024 15,468 43.51 July 1, 2023 4,769 78.37 December 1, 2021 5,067 52.36

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Commitments We have entered into various non-cancelable operating lease agreements for certain of our office space and equipment with original lease periods expiring between 2020 and 2030. For additional information regarding our lease agreements, see Note 14 in our Notes to Consolidated Financial Statements in the Annual Report on Form 10-K for the year ended December 31, 2019. Purchase Commitments Purchase commitments primarily include various non-cancelable agreements to purchase content related to our mobile applications and websites and certain cloud computing services as well as homes we are under contract to purchase through Zillow Offers but that have not closed as of the respective date. The amounts due for non-cancelable purchase commitments, excluding homes under contract, as of June 30, 2020, are as follows (in thousands): Purchase Obligations 2020 $ 8,254 2021 17,627 2022 3,043 2023 507 Total future purchase commitments $ 29,431 As of June 30, 2020, the value of homes under contract that have not closed was $51.9 million. Letters of Credit As of June 30, 2020, we have outstanding letters of credit of approximately $16.9 million, which secure our lease obligations in connection with certain of our office space operating leases. Surety Bonds In the course of business, we are required to provide financial commitments in the form of surety bonds to third parties as a guarantee of our performance on and our compliance with certain obligations. If we were to fail to perform or comply with these obligations, any draws upon surety bonds issued on our behalf would then trigger our payment obligation to the surety bond issuer. We have outstanding surety bonds issued for our benefit of approximately $9.8 million and $10.2 million, respectively, as of June 30, 2020 and December 31, 2019. Legal Proceedings We are involved in a number of legal proceedings concerning matters arising in connection with the conduct of our business activities, some of which are at preliminary stages and some of which seek an indeterminate amount of damages. We regularly evaluate the status of legal proceedings in which we are involved to assess whether a loss is probable or there is a reasonable possibility that a loss or additional loss may have been incurred to determine if accruals are appropriate. We further evaluate each legal proceeding to assess whether an estimate of possible loss or range of loss can be made if accruals are not appropriate. For certain cases described below, management is unable to provide a meaningful estimate of the possible loss or range of possible loss because, among other reasons, (i) the proceedings are in preliminary stages; (ii) specific damages have not been sought; (iii) damages sought are, in our view, unsupported and/or exaggerated; (iv) there is uncertainty as to the outcome of pending appeals or motions; (v) there are significant factual issues to be resolved; and/or (vi) there are novel legal issues or unsettled legal theories presented. For these cases, however, management does not believe, based on currently available information, that the outcomes of these proceedings will have a material effect on our financial position, results of operations or cash flow. For the matters discussed below, we have not recorded any material accruals as of June 30, 2020 or December 31, 2019. In July 2015, VHT, Inc. (“VHT”) filed a complaint against us in the United States District Court for the Western District of Washington alleging copyright infringement of VHT’s images on the Zillow Digs site. In January 2016, VHT filed an amended complaint alleging copyright infringement of VHT’s images on the Zillow Digs site as well as the Zillow listing site. In December 2016, the court granted a motion for partial summary judgment that dismissed VHT’s claims with respect to the Zillow listing site. A federal jury trial began on January 23, 2017, and on February 9, 2017, the jury returned a verdict finding that the Company had infringed VHT’s copyrights in images displayed or saved to the Digs site. The jury awarded VHT $79,875 in actual damages and approximately $8.2 million in statutory damages. In March 2017, the Company filed motions in the district court seeking judgment for the Company on certain claims that are the subject of the verdict, and for a new trial on others. On June 20, 2017, the judge ruled and granted in part our motions, finding that VHT failed to present sufficient evidence to prove direct copyright infringement for a portion of the images, reducing the total damages to approximately $4.1 million. On March 15, 2019, after we filed an appeal with the Ninth Circuit Court of Appeals seeking review of the final judgment and certain prior rulings entered by the District Court, the Ninth Circuit Court of Appeals issued an opinion that, among other things, (i) affirmed the District Court’s grant of summary judgment in favor of Zillow on direct infringement of images on Zillow’s listing site, (ii) affirmed the district court’s grant in favor of Zillow of judgment notwithstanding the verdict on certain images that were displayed on the Zillow Digs site, (iii) remanded consideration of the issue whether VHT’s images on the Zillow Digs site were part of a compilation or individual photos, and (iv) vacated the jury’s finding of willful infringement. On October 7, 2019, the United States Supreme Court denied VHT’s petition for writ of certiorari seeking review of certain rulings by the Ninth Circuit Court of Appeals. On December 6, 2019, the Company filed a motion for summary judgment with the District Court seeking a ruling that VHT’s images are a compilation, or in the alternative, seeking a dismissal of the case based on a recent United States Supreme Court ruling. On May 8, 2020, the District Court denied the Company’s motion for summary judgment and granted VHT’s motion for summary judgment on the issue of whether the remaining photos were a compilation. We do not believe there is a reasonable possibility that a material loss will be incurred related to this lawsuit. In August and September 2017, two purported class action lawsuits were filed against us and certain of our executive officers, alleging, among other things, violations of federal securities laws on behalf of a class of those who purchased our common stock between February 12, 2016 and August 8, 2017. One of those purported class actions, captioned Vargosko v. Zillow Group, Inc. et al , was brought in the U.S. District Court for the Central District of California. The other purported class action lawsuit, captioned Shotwell v. Zillow Group, Inc. et al , was brought in the U.S. District Court for the Western District of Washington. The complaints allege, among other things, that during the period between February 12, 2016 and August 8, 2017, we issued materially false and misleading statements regarding our business practices. The complaints seek to recover, among other things, alleged damages sustained by the purported class members as a result of the alleged misconduct. In November 2017, an amended complaint was filed against us and certain of our executive officers in the Shotwell v. Zillow Group purported class action lawsuit, extending the beginning of the class period to November 17, 2014. In January 2018, the Vargosko v. Zillow Group purported class action lawsuit was transferred to the U.S. District Court for the Western District of Washington and consolidated with the Shotwell v. Zillow Group purported class action lawsuit. In February 2018, the plaintiffs filed a consolidated amended complaint, and in April 2018, we filed our motion to dismiss the consolidated amended complaint. In October 2018, our motion to dismiss was granted without prejudice, and in November 2018, the plaintiffs filed a second consolidated amended complaint, which we moved to dismiss in December 2018. On April 19, 2019, our motion to dismiss the second consolidated amended complaint was denied, and we filed our answer to the second amended complaint on May 3, 2019. On October 11, 2019, plaintiffs filed a motion for class certification, and we filed our motion in opposition on March 20, 2020. The plaintiffs filed a reply in further support of their motion on May 29, 2020. We have denied the allegations of wrongdoing and intend to vigorously defend the claims in this lawsuit. We do not believe a loss related to this lawsuit is probable. In October and November 2017 and January and February 2018, four shareholder derivative lawsuits were filed in the U.S. District Court for the Western District of Washington and the Superior Court of the State of Washington, King County, against certain of our executive officers and directors seeking unspecified damages on behalf of the Company and certain other relief, such as reform to corporate governance practices. The plaintiffs in the derivative suits (in which the Company is a nominal defendant) allege, among other things, that the defendants breached their fiduciary duties in connection with oversight of the Company’s public statements and legal compliance, and as a result of the breach of such fiduciary duties, the Company was damaged, and defendants were unjustly enriched. Certain of the plaintiffs also allege, among other things, violations of Section 14(a) of the Securities Exchange Act of 1934 and waste of corporate assets. On February 5, 2018, the U.S. District Court for the Western District of Washington consolidated the two federal shareholder derivative lawsuits pending in that court. On February 16, 2018, the Superior Court of the State of Washington, King County, consolidated the two shareholder derivative lawsuits pending in that court. All four of the shareholder derivative lawsuits were stayed until our motion to dismiss the second consolidated amended complaint in the securities class action lawsuit discussed above was denied in April 2019. On July 8, 2019, the plaintiffs in the consolidated federal derivative lawsuit filed a consolidated shareholder derivative complaint, which we moved to dismiss on August 22, 2019. On February 28, 2020, our motion to dismiss the consolidated shareholder derivative complaint was denied. On May 18, 2020 we filed an answer in the consolidated federal derivative lawsuit. Our answer in the consolidated state derivative matter is due on August 24, 2020. We do not believe a loss is probable related to these lawsuits. On September 17, 2019, International Business Machines Corporation (“IBM”) filed a complaint against us in the United States District Court for the Central District of California, alleging, among other things, that the Company has infringed and continues to willfully infringe seven patents held by IBM and seeks unspecified damages, including a request that the amount of compensatory damages be trebled, injunctive relief and costs and reasonable attorneys’ fees. On December 2, 2019, IBM filed an amended complaint. On December 16, 2019, we filed a motion to transfer venue and/or to dismiss the complaint. The Company’s motion to transfer venue to the United States District Court for the Western District of Washington was granted on May 28, 2020. We filed our answer with counterclaims in response to the amended complaint on June 11, 2020. On July 2, 2020, IBM filed a motion to dismiss our counterclaims. In response to IBM’s motion, on July 22, 2020, we filed an amended answer with counterclaims. We deny the allegations of any wrongdoing and intend to vigorously defend the claims in the lawsuit. There is a reasonable possibility that a loss may be incurred related to this complaint; however, the possible loss or range of loss is not estimable. On July 21, 2020, IBM filed a second action against us in the United States District Court for the Western District of Washington, alleging, among other things that the Company has infringed and continues to willfully infringe five patents held by IBM and seeks unspecified damages. We deny the allegations of any wrongdoing and intend to vigorously defend the claims in the lawsuit. We do not believe a loss related to this lawsuit is probable. In addition to the matters discussed above, from time to time, we are involved in litigation and claims that arise in the ordinary course of business. Although we cannot be certain of the outcome of any such litigation or claims, nor the amount of damages and exposure that we could incur, we currently believe that the final disposition of such matters will not have a material effect on our business, financial position, results of operations or cash flow. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors. Indemnifications In the ordinary course of business, we enter into contractual arrangements under which we agree to provide indemnification of varying scope and terms to business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of the breach of such agreements and out of intellectual property infringement claims made by third parties. In addition, we have agreements that indemnify certain issuers of surety bonds against losses that they may incur as a result of executing surety bonds on our behalf. For our indemnification arrangements, payment may be conditional on the other party making a claim pursuant to the procedures specified in the particular contract. Further, our obligations under these agreements may be limited in terms of time and/or amount, and in some instances, we may have recourse against third parties for certain payments. In addition, we have indemnification agreements with certain of our directors and executive officers that require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The terms of such obligations may vary.

Employee Benefit Plan

Employee Benefit Plan	6 Months Ended
	Jun. 30, 2020
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit PlanWe have a defined contribution 401(k) retirement plan covering Zillow Group employees who have met certain eligibility requirements (the “Zillow Group 401(k) Plan”). Eligible employees may contribute pretax compensation up to a maximum amount allowable under the Internal Revenue Service limitations. Employee contributions and earnings thereon vest immediately. We currently match up to 4% of employee contributions under the Zillow Group 401(k) Plan. The total expense related to the Zillow Group 401(k) Plan was $6.4 million and $5.2 million, respectively, for the three months ended June 30, 2020 and 2019, and $12.8 million and $10.1 million, respectively, for the six months ended June 30, 2020 and 2019.

Segment Information and Revenue

Segment Information and Revenue	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Segment Information and Revenue	Segment Information and Revenue We have three operating and reportable segments, which have been identified based on the way in which our chief operating decision-maker manages our business, makes operating decisions and evaluates operating performance. The chief executive officer acts as the chief operating decision-maker and reviews financial and operational information for the Homes, Internet, Media & Technology (“IMT”) and Mortgages segments. The Homes segment includes the financial results from Zillow Group’s purchase and sale of homes directly through Zillow Offers and the financial results from title and escrow services through Zillow Closing Services. The IMT segment includes the financial results for the Premier Agent, rentals and new construction marketplaces, dotloop and display, as well as revenue from the sale of various other marketing and business products and services to real estate professionals. The Mortgages segment includes financial results for advertising sold to mortgage lenders and other mortgage professionals, mortgage originations through Zillow Home Loans and the sale of mortgages on the secondary market, as well as Mortech mortgage software solutions. Revenue and costs are directly attributed to our segments when possible. However, due to the integrated structure of our business, certain costs incurred by one segment may benefit the other segments. These costs primarily include headcount-related expenses, general and administrative expenses including executive, finance, accounting, legal, human resources, recruiting and facilities costs, product development and data acquisition costs and marketing and advertising costs. These costs are allocated to each segment based on the estimated benefit each segment receives from such expenditures. The chief executive officer reviews information about our revenue categories as well as statement of operations data inclusive of income (loss) before income taxes by segment. This information is included in the following tables for the periods presented (in thousands): Three Months Ended Three Months Ended Homes IMT Mortgages Homes IMT Mortgages Revenue: Zillow Offers $ 453,816 $ — $ — $ 248,924 $ — $ — Premier Agent — 191,962 — — 231,961 — Other 436 88,377 — — 91,708 — Mortgages — — 33,761 — — 26,985 Total revenue 454,252 280,339 33,761 248,924 323,669 26,985 Costs and expenses: Cost of revenue 431,788 23,387 5,896 240,732 26,059 4,430 Sales and marketing 47,877 96,026 11,695 37,409 135,440 14,584 Technology and development 28,918 93,176 6,763 18,198 94,261 7,871 General and administrative 21,902 53,884 9,725 17,808 54,671 10,360 Integration costs — — — — — 293 Total costs and expenses 530,485 266,473 34,079 314,147 310,431 37,538 Income (loss) from operations (76,233) 13,866 (318) (65,223) 13,238 (10,553) Segment other income — 5,300 385 — — 402 Segment interest expense (3,825) — (307) (5,899) — (287) Income (loss) before income taxes (1) $ (80,058) $ 19,166 $ (240) $ (71,122) $ 13,238 $ (10,438) Six Months Ended Six Months Ended Homes IMT Mortgages Homes IMT Mortgages Revenue: Zillow Offers $ 1,222,928 $ — $ — $ 377,396 $ — $ — Premier Agent — 434,068 — — 449,696 — Other 1,197 176,937 — — 172,245 — Mortgages — — 59,043 — — 54,345 Total revenue 1,224,125 611,005 59,043 377,396 621,941 54,345 Costs and expenses: Cost of revenue 1,163,987 47,705 11,051 363,151 50,310 9,108 Sales and marketing 119,466 216,199 24,581 58,271 262,094 28,655 Technology and development 61,456 188,204 14,115 30,479 182,230 15,391 General and administrative 45,323 112,638 19,835 32,165 125,521 20,927 Impairment costs — 73,900 2,900 — — — Integration costs — — — — — 645 Total costs and expenses 1,390,232 638,646 72,482 484,066 620,155 74,726 Income (loss) from operations (166,107) (27,641) (13,439) (106,670) 1,786 (20,381) Segment other income — 5,300 587 — — 715 Segment interest expense (11,909) — (533) (9,657) — (388) Income (loss) before income taxes (1) $ (178,016) $ (22,341) $ (13,385) $ (116,327) $ 1,786 $ (20,054) (1) The following table presents the reconciliation of total segment loss before income taxes to consolidated loss before income taxes for the periods presented (in thousands, unaudited): Three Months Ended Six Months Ended 2020 2019 2020 2019 Total segment loss before income taxes $ (61,132) $ (68,322) $ (213,742) $ (134,595) Corporate interest expense (33,458) (12,711) (62,740) (25,318) Corporate other income 4,430 9,056 13,821 17,911 Gain on partial extinguishment of 2021 Notes 6,391 — 6,391 — Consolidated loss before income taxes $ (83,769) $ (71,977) $ (256,270) $ (142,002) Certain corporate items are not directly attributable to any of our segments, including the gain on the partial extinguishment of the 2021 Notes, interest income earned on our short-term investments included in Other income and interest costs on our convertible senior notes included in Interest expense.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements include Zillow Group, Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. These condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and accompanying notes included in Zillow Group, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the SEC on February 19, 2020. The condensed consolidated balance sheet as of December 31, 2019, included herein, was derived from the audited financial statements of Zillow Group, Inc. as of that date. The unaudited condensed consolidated interim financial statements, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary to present fairly our financial position as of June 30, 2020, our results of operations, comprehensive loss and shareholders’ equity for the three and six month periods ended June 30, 2020 and 2019, and our cash flows for the six month periods ended June 30, 2020 and 2019. The results of the three and six month periods ended June 30, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any interim period or for any other future year.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. On an ongoing basis, we evaluate our estimates, including those related to the net realizable value of inventory, amortization period and recoverability of contract cost assets, website and software development costs, recoverability of long-lived assets and intangible assets with definite lives, share-based compensation, income taxes, business combinations and the recoverability of goodwill, among others. To the extent there are material differences between these estimates, judgments or assumptions and actual results, our financial statements will be affected. The COVID-19 pandemic has introduced significant additional uncertainty with respect to estimates, judgments and assumptions, which may materially impact the estimates previously listed, among others.
Recently Issued Accounting Standards Not Yet Adopted	Recently Issued Accounting Standards Not Yet Adopted In March 2020, the Financial Accounting Standards Board (“FASB”) issued guidance which provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions that reference the London Inter-Bank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform. This guidance is optional for a limited period of time to ease the potential burden in accounting for, or recognizing the effects of, reference rate reform on financial reporting. This guidance is effective from March 12, 2020 through December 31, 2022. Entities may elect to adopt the amendments for contract modifications as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. We expect to apply some of the expedients and exceptions provided in this guidance to our credit facilities, warehouse line of credit and master repurchase agreement, all of which reference LIBOR in the applicable interest rate. While the goal of the reference rate reform transition is for it to be economically neutral to entities, we have not yet determined the impact the adoption of this guidance will have on our financial position, results of operations or cash flows.
Fair Value Measurements	Accounting standards define fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. The standards also establish a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value: • Level 1 — Quoted prices in active markets for identical assets or liabilities. • Level 2 — Assets and liabilities valued based on observable market data for similar instruments, such as quoted prices for similar assets or liabilities. • Level 3 — Unobservable inputs that are supported by little or no market activity; instruments valued based on the best available data, some of which is internally developed, and considers risk premiums that a market participant would require. We applied the following methods and assumptions in estimating our fair value measurements: Cash equivalents — The fair value measurement of money market funds is based on quoted market prices in active markets. The fair value measurement of treasury bills are based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means. Short-term investments — The fair value measurement of our short-term investments is based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means. Restricted cash — Restricted cash consists of cash received from the resale of homes through Zillow Offers which may be used to repay amounts borrowed on our credit facilities (see Note 12) and amounts held in escrow related to funding home purchases in our mortgage origination business. The carrying value of restricted cash approximates fair value due to the short period of time amounts borrowed on the credit facilities are outstanding and amounts are held in escrow. Mortgage loans held for sale — The fair value of mortgage loans held for sale is generally calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics. Interest rate lock commitments — The fair value of interest rate lock commitments (“IRLCs”) is calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics. Expired commitments are excluded from the fair value measurement. We generally only issue IRLCs for products that meet specific purchaser guidelines. Since not all IRLCs will become closed loans, we adjust our fair value measurements for the estimated amount of IRLCs that will not close. This adjustment is effected through the pull-through rate, which represents the probability that an interest rate lock commitment will ultimately result in a closed loan. The pull-through rate is based on estimated changes in market conditions, loan stage and historical borrower behavior. Pull-through rates are directly related to the fair value of IRLCs as an increase in the pull-through rate, in isolation, would result in an increase in the fair value measurement. Conversely, a decrease in the pull-through rate, in isolation, would result in a decrease in the fair value measurement. Changes in the fair value of IRLCs are included within Mortgages revenue in our condensed consolidated statements of operations. Forward contracts — The fair value of mandatory loan sales commitments and derivative instruments such as forward sales of mortgage-backed securities that are utilized as economic hedging instruments are calculated by reference to quoted prices for similar assets.
Segment Reporting	We have three operating and reportable segments, which have been identified based on the way in which our chief operating decision-maker manages our business, makes operating decisions and evaluates operating performance. The chief executive officer acts as the chief operating decision-maker and reviews financial and operational information for the Homes, Internet, Media & Technology (“IMT”) and Mortgages segments. The Homes segment includes the financial results from Zillow Group’s purchase and sale of homes directly through Zillow Offers and the financial results from title and escrow services through Zillow Closing Services. The IMT segment includes the financial results for the Premier Agent, rentals and new construction marketplaces, dotloop and display, as well as revenue from the sale of various other marketing and business products and services to real estate professionals. The Mortgages segment includes financial results for advertising sold to mortgage lenders and other mortgage professionals, mortgage originations through Zillow Home Loans and the sale of mortgages on the secondary market, as well as Mortech mortgage software solutions. Revenue and costs are directly attributed to our segments when possible. However, due to the integrated structure of our business, certain costs incurred by one segment may benefit the other segments. These costs primarily include headcount-related expenses, general and administrative expenses including executive, finance, accounting, legal, human resources, recruiting and facilities costs, product development and data acquisition costs and marketing and advertising costs. These costs are allocated to each segment based on the estimated benefit each segment receives from such expenditures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurement Inputs and Valuation Techniques	The following table presents the range and weighted average pull-through rates used in determining the fair value of IRLCs as of the periods presented: June 30, 2020 December 31, 2019 Range 40% - 100% 56% - 100% Weighted average 70% 78%
Summary of Balances of Cash Equivalents and Investments	The following tables present the balances of assets and liabilities measured at fair value on a recurring basis, by level within the fair value hierarchy, as of the dates presented (in thousands): June 30, 2020 Total Level 1 Level 2 Level 3 Cash equivalents: Money market funds $ 1,784,896 $ 1,784,896 $ — $ — Treasury bills 70,189 — 70,189 — Short-term investments: Treasury bills 963,231 — 963,231 — U.S. government agency securities 465,715 — 465,715 — Corporate notes and bonds 30,213 — 30,213 — Municipal securities 16,538 — 16,538 — Commercial paper 14,972 — 14,972 — Certificates of deposit 498 — 498 — Mortgage origination-related: Mortgage loans held for sale 75,021 — 75,021 — IRLCs 5,091 — — 5,091 Forward contracts - other current liabilities 961 — 961 — Total $ 3,427,325 $ 1,784,896 $ 1,637,338 $ 5,091 December 31, 2019 Total Level 1 Level 2 Cash equivalents: Money market funds $ 872,431 $ 872,431 $ — U.S. government agency securities 35,009 — 35,009 Commercial paper 31,113 — 31,113 Treasury bills 6,441 — 6,441 Corporate notes and bonds 1,065 — 1,065 Certificates of deposit 249 — 249 Short-term investments: U.S. government agency securities 862,154 — 862,154 Corporate notes and bonds 159,431 — 159,431 Commercial paper 150,267 — 150,267 Treasury bills 80,003 — 80,003 Municipal securities 27,889 — 27,889 Certificates of deposit 1,245 — 1,245 Mortgage origination-related: Mortgage loans held for sale 36,507 — 36,507 IRLCs 937 — 937 Forward contracts - other current assets 7 — 7 Forward contracts - other current liabilities (60) — (60) Total $ 2,264,688 $ 872,431 $ 1,392,257
Schedule of Changes in IRLCs	The following table presents the changes in our IRLCs during the three and six month periods ended June 30, 2020 (in thousands): Three Months Ended Six Months Ended Balance, beginning of the period $ 2,225 $ 937 Issuances 10,142 15,507 Transfers (8,586) (13,142) Fair value changes recognized in earnings 1,310 1,789 Balance, end of period $ 5,091 $ 5,091 (1) Beginning balance represents transfers of IRLCs from Level 2 to Level 3 within the fair value hierarchy as of January 1, 2020.

Cash and Cash Equivalents, Sh_2

Cash and Cash Equivalents, Short-term Investments and Restricted Cash (Tables)	6 Months Ended
	Jun. 30, 2020
Cash and Cash Equivalents [Abstract]
Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Market Value of Cash and Cash Equivalents and Available-for-Sale Investments	The following tables present the amortized cost, gross unrealized gains and losses and estimated fair market value of our cash and cash equivalents, available-for-sale investments and restricted cash as of the dates presented (in thousands): June 30, 2020 Amortized Gross Gross Estimated Cash $ 190,389 $ — $ — $ 190,389 Cash equivalents: Money market funds 1,784,896 — — 1,784,896 Treasury bills 70,189 — — 70,189 Short-term investments: Treasury bills 963,200 41 (10) 963,231 U.S. government agency securities 463,806 1,909 — 465,715 Corporate notes and bonds 30,094 119 — 30,213 Municipal securities 16,519 19 — 16,538 Commercial paper 14,972 — — 14,972 Certificates of deposit 498 — — 498 Restricted cash 33,620 — — 33,620 Total $ 3,568,183 $ 2,088 $ (10) $ 3,570,261 December 31, 2019 Amortized Gross Gross Estimated Cash $ 194,955 $ — $ — $ 194,955 Cash equivalents: Money market funds 872,431 — — 872,431 U.S. government agency securities 35,011 — (2) 35,009 Commercial paper 31,113 — — 31,113 Treasury bills 6,441 — — 6,441 Corporate notes and bonds 1,065 — — 1,065 Certificates of deposit 249 — — 249 Short-term investments: U.S. government agency securities 861,862 365 (73) 862,154 Corporate notes and bonds 159,382 91 (42) 159,431 Commercial paper 150,267 — — 150,267 Treasury bills 79,989 14 — 80,003 Municipal securities 27,836 56 (3) 27,889 Certificates of deposit 1,245 — — 1,245 Restricted cash 89,646 — — 89,646 Total $ 2,511,492 $ 526 $ (120) $ 2,511,898

Accounts Receivable, net (Table

Accounts Receivable, net (Tables)	6 Months Ended
	Jun. 30, 2020
Receivables [Abstract]
Schedule of Accounts Receivable, Net	The following table presents the changes in the allowance for doubtful accounts for the six months ended June 30, 2020 (in thousands): Balance as of January 1, 2020 $ 4,522 Credit loss expense 1,614 Less: write-offs, net of recoveries and other adjustments (3,854) Balance as of June 30, 2020 $ 2,282

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 30, 2020
Inventory Disclosure [Abstract]
Components of Net Inventory	The following table presents the components of inventory, net of applicable lower of cost or net realizable value adjustments, as of the dates presented (in thousands): June 30, 2020 December 31, 2019 Work-in-process $ 12,164 $ 152,171 Finished goods 123,237 684,456 Inventory $ 135,401 $ 836,627

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Detail of Property and Equipment	The following table presents the detail of property and equipment as of the dates presented (in thousands): June 30, 2020 December 31, 2019 Website development costs $ 157,468 $ 149,648 Leasehold improvements 107,139 81,981 Construction-in-progress 51,482 45,337 Office equipment, furniture and fixtures 42,236 36,582 Computer equipment 31,801 31,942 Property and equipment 390,126 345,490 Less: accumulated amortization and depreciation (194,379) (175,001) Property and equipment, net $ 195,747 $ 170,489

Intangible Assets, net (Tables)

Intangible Assets, net (Tables)	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	The following tables present the detail of intangible assets subject to amortization as of the dates presented (in thousands): June 30, 2020 Cost Accumulated Net Trade names and trademarks $ 36,500 $ (1,274) $ 35,226 Customer relationships 102,600 (81,372) 21,228 Developed technology 107,200 (87,340) 19,860 Software 40,744 (25,031) 15,713 Intangibles-in-progress 10,054 — 10,054 Purchased content 50,552 (45,726) 4,826 Lender licenses 400 (317) 83 Total $ 348,050 $ (241,060) $ 106,990 December 31, 2019 Cost Accumulated Net Customer relationships $ 102,600 $ (73,770) $ 28,830 Developed technology 107,200 (81,383) 25,817 Software 35,527 (20,843) 14,684 Purchased content 47,298 (40,636) 6,662 Intangibles-in-progress 6,391 — 6,391 Lender licenses 400 (217) 183 Total $ 299,416 $ (216,849) $ 82,567

Deferred Revenue (Tables)

Deferred Revenue (Tables)	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Change in Deferred Revenue	The following tables present the changes in deferred revenue for the periods presented (in thousands): Three Months Ended Balance as of April 1, 2020 $ 35,347 Deferral of revenue 222,895 Less: Revenue recognized (213,728) Balance as of June 30, 2020 $ 44,514 Six Months Ended Balance as of January 1, 2020 $ 39,747 Deferral of revenue 476,624 Less: Revenue recognized (471,857) Balance as of June 30, 2020 $ 44,514

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Schedule of Carrying Value of Debt	The following table presents the carrying values of Zillow Group’s debt as of the periods presented (in thousands): June 30, 2020 December 31, 2019 Homes Segment Credit facilities: Goldman Sachs Bank USA $ 19,632 $ 39,244 Citibank, N.A. 33,037 296,369 Credit Suisse AG, Cayman Islands 64,549 355,911 Total Homes Segment debt 117,218 691,524 Mortgages Segment Repurchase agreement: Citibank, N.A. 33,918 394 Warehouse line of credit: Comerica Bank 35,896 30,033 Total Mortgages Segment debt 69,814 30,427 Convertible Senior Notes 1.375% convertible senior notes due 2026 337,171 327,187 2.75% convertible senior notes due 2025 401,786 — 0.75% convertible senior notes due 2024 507,039 490,538 1.50% convertible senior notes due 2023 318,348 310,175 2.00% convertible senior notes due 2021 245,997 415,502 2.75% convertible senior notes due 2020 9,637 9,637 Total convertible senior notes 1,819,978 1,553,039 Total $ 2,007,010 $ 2,274,990
Schedule of Revolving Credit Facilities and Lines of Credit	The following table summarizes certain details related to our credit facilities (in thousands, except interest rates): Lender Final Maturity Date Maximum Borrowing Capacity Weighted Average Interest Rate Goldman Sachs Bank USA April 20, 2022 $ 500,000 3.91 % Citibank, N.A. January 31, 2022 500,000 4.69 % Credit Suisse AG, Cayman Islands July 31, 2021 500,000 4.62 % Total $ 1,500,000 Lender Maturity Date Maximum Borrowing Capacity Weighted Average Interest Rate Citibank, N.A. October 27, 2020 $ 75,000 1.88 % Comerica Bank June 26, 2021 50,000 2.81 % Total $ 125,000
Schedule of Convertible Senior Notes	The following tables summarize certain details related to our outstanding convertible senior notes as of the periods presented (in thousands, except interest rates): June 30, 2020 December 31, 2019 Maturity Date Aggregate Principal Amount Stated Interest Rate Effective Interest Rate First Interest Payment Date Semi-Annual Interest Payment Dates Unamortized Debt Discount and Debt Issuance Costs Fair Value Unamortized Debt Discount and Debt Issuance Costs Fair Value September 1, 2026 $ 500,000 1.375 % 8.10 % March 1, 2020 March 1; September 1 $ 162,829 $ 705,000 $ 172,813 $ 597,380 May 15, 2025 565,000 2.75 % 10.32 % November 15, 2020 May 15; November 15 163,214 659,756 — — September 1, 2024 673,000 0.75 % 7.68 % March 1, 2020 March 1; September 1 165,961 957,659 182,462 819,378 July 1, 2023 373,750 1.50 % 6.99 % January 1, 2019 January 1; July 1 55,402 388,113 63,575 356,464 December 1, 2021 265,330 2.00 % 7.43 % June 1, 2017 June 1; December 1 19,333 326,688 44,498 514,312 December 15, 2020 9,637 2.75 % N/A N/A June 15; December 15 — 16,842 — 16,842 Total $ 2,386,717 $ 566,739 $ 3,054,058 $ 463,348 $ 2,304,376 Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Maturity Date Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense September 1, 2026 $ 1,719 $ 4,922 $ 120 $ 6,761 $ — $ — $ — $ — May 15, 2025 2,007 3,148 168 5,323 — — — — September 1, 2024 1,262 8,095 278 9,635 — — — — July 1, 2023 1,402 3,749 366 5,517 1,402 3,496 342 5,240 December 1, 2021 1,803 3,945 408 6,156 2,300 4,677 484 7,461 December 15, 2020 66 — — 66 66 — — 66 Total $ 8,259 $ 23,859 $ 1,340 $ 33,458 $ 3,768 $ 8,173 $ 826 $ 12,767 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Maturity Date Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense Contractual Coupon Interest Amortization of Debt Discount Amortization of Debt Issuance Costs Interest Expense September 1, 2026 $ 3,438 $ 9,746 $ 238 $ 13,422 $ — $ — $ — $ — May 15, 2025 2,007 3,148 168 5,323 — — — — September 1, 2024 2,510 15,956 545 19,011 — — — — July 1, 2023 2,804 7,446 727 10,977 2,804 6,933 678 10,415 December 1, 2021 4,103 8,856 916 13,875 4,600 9,268 959 14,827 December 15, 2020 132 — — 132 132 — — 132 Total $ 14,994 $ 45,152 $ 2,594 $ 62,740 $ 7,536 $ 16,201 $ 1,637 $ 25,374 The following table summarizes the conversion and redemption options with respect to the Notes: Maturity Date Early Conversion Date Conversion Rate Conversion Price Optional Redemption Date September 1, 2026 March 1, 2026 22.9830 $ 43.51 September 5, 2023 May 15, 2025 November 15, 2024 14.8810 67.20 May 22, 2023 September 1, 2024 March 1, 2024 22.9830 43.51 September 5, 2022 July 1, 2023 April 1, 2023 12.7592 78.37 July 6, 2021 December 1, 2021 September 1, 2021 19.0985 52.36 December 6, 2019 The following table summarizes certain details related to the capped call confirmations with respect to certain of the convertible senior notes: Maturity Date Initial Cap Price Cap Price Premium September 1, 2026 $ 80.5750 150 % September 1, 2024 72.5175 125 % July 1, 2023 105.45 85 % December 1, 2021 69.19 85 %

Share-Based Awards (Tables)

Share-Based Awards (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Summary of Option Award Activity	The following table summarizes option award activity for the six months ended June 30, 2020: Number Weighted- Weighted- Aggregate Outstanding at January 1, 2020 29,634,296 $ 35.95 6.28 $ 331,107 Granted 4,833,605 49.24 Exercised (6,324,858) 29.25 Forfeited or cancelled (674,462) 40.76 Outstanding at June 30, 2020 27,468,581 39.71 6.74 493,801 Vested and exercisable at June 30, 2020 14,708,916 35.84 4.96 320,951
Fair Value of Options Granted, Estimated at Date of Grant Using Black Scholes Merton Option Pricing Model	The fair value of options granted is estimated at the date of grant using the Black-Scholes-Merton option-pricing model, assuming no dividends and with the following assumptions for the periods presented: Three Months Ended Six Months Ended 2020 2019 2020 2019 Expected volatility 51% 45% 45%-51% 45%-47% Expected dividend yield — — — — Risk-free interest rate 0.33% 2.00% 0.33%-0.93% 2.00%-2.53% Weighted-average expected life 5.00 years 5.00 years 5.00-5.50 years 4.75-5.25 years Weighted-average fair value of options granted $20.21 $16.96 $20.69 $16.79
Summary of Restricted Stock Units Activity	The following table summarizes activity for restricted stock units for the six months ended June 30, 2020: Restricted Weighted- Unvested outstanding at January 1, 2020 7,052,767 $ 40.01 Granted 3,665,016 49.30 Vested (1,414,158) 40.65 Forfeited (513,401) 41.62 Unvested outstanding at June 30, 2020 8,790,224 43.69
Effects of Share Based Compensation in Consolidated Statements of Operations	The following table presents the effects of share-based compensation expense in our condensed consolidated statements of operations during the periods presented (in thousands): Three Months Ended Six Months Ended 2020 2019 2020 2019 Cost of revenue $ 1,119 $ 936 $ 2,292 $ 1,816 Sales and marketing 9,116 6,801 16,109 12,451 Technology and development 21,666 18,399 40,583 33,908 General and administrative 20,450 17,496 37,162 61,581 Total $ 52,351 $ 43,632 $ 96,146 $ 109,756

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share	For the periods presented, the following Class A common stock and Class C capital stock equivalents were excluded from the calculations of diluted net loss per share because their effect would have been antidilutive (in thousands): Three Months Ended Six Months Ended 2020 2019 2020 2019 Weighted-average Class A common stock and Class C capital stock option awards outstanding 25,202 19,502 22,649 19,656 Weighted-average Class A common stock and Class C capital stock restricted stock units outstanding 9,086 7,230 8,354 6,548 Class A common stock issuable upon conversion of the convertible notes maturing in 2020 400 411 400 411 Class C capital stock issuable upon conversion of the convertible notes maturing in 2021, 2024 and 2026 7,232 — 7,316 — Total Class A common stock and Class C capital stock equivalents 41,920 27,143 38,719 26,615 Maturity Date Conversion Spread Conversion Price per Share September 1, 2026 11,492 $ 43.51 May 15, 2025 8,408 67.20 September 1, 2024 15,468 43.51 July 1, 2023 4,769 78.37 December 1, 2021 5,067 52.36

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Purchase Commitments for Content Related to Mobile Applications and Websites	The amounts due for non-cancelable purchase commitments, excluding homes under contract, as of June 30, 2020, are as follows (in thousands): Purchase Obligations 2020 $ 8,254 2021 17,627 2022 3,043 2023 507 Total future purchase commitments $ 29,431

Segment Information and Reven_2

Segment Information and Revenue (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Revenue Categories	This information is included in the following tables for the periods presented (in thousands): Three Months Ended Three Months Ended Homes IMT Mortgages Homes IMT Mortgages Revenue: Zillow Offers $ 453,816 $ — $ — $ 248,924 $ — $ — Premier Agent — 191,962 — — 231,961 — Other 436 88,377 — — 91,708 — Mortgages — — 33,761 — — 26,985 Total revenue 454,252 280,339 33,761 248,924 323,669 26,985 Costs and expenses: Cost of revenue 431,788 23,387 5,896 240,732 26,059 4,430 Sales and marketing 47,877 96,026 11,695 37,409 135,440 14,584 Technology and development 28,918 93,176 6,763 18,198 94,261 7,871 General and administrative 21,902 53,884 9,725 17,808 54,671 10,360 Integration costs — — — — — 293 Total costs and expenses 530,485 266,473 34,079 314,147 310,431 37,538 Income (loss) from operations (76,233) 13,866 (318) (65,223) 13,238 (10,553) Segment other income — 5,300 385 — — 402 Segment interest expense (3,825) — (307) (5,899) — (287) Income (loss) before income taxes (1) $ (80,058) $ 19,166 $ (240) $ (71,122) $ 13,238 $ (10,438) Six Months Ended Six Months Ended Homes IMT Mortgages Homes IMT Mortgages Revenue: Zillow Offers $ 1,222,928 $ — $ — $ 377,396 $ — $ — Premier Agent — 434,068 — — 449,696 — Other 1,197 176,937 — — 172,245 — Mortgages — — 59,043 — — 54,345 Total revenue 1,224,125 611,005 59,043 377,396 621,941 54,345 Costs and expenses: Cost of revenue 1,163,987 47,705 11,051 363,151 50,310 9,108 Sales and marketing 119,466 216,199 24,581 58,271 262,094 28,655 Technology and development 61,456 188,204 14,115 30,479 182,230 15,391 General and administrative 45,323 112,638 19,835 32,165 125,521 20,927 Impairment costs — 73,900 2,900 — — — Integration costs — — — — — 645 Total costs and expenses 1,390,232 638,646 72,482 484,066 620,155 74,726 Income (loss) from operations (166,107) (27,641) (13,439) (106,670) 1,786 (20,381) Segment other income — 5,300 587 — — 715 Segment interest expense (11,909) — (533) (9,657) — (388) Income (loss) before income taxes (1) $ (178,016) $ (22,341) $ (13,385) $ (116,327) $ 1,786 $ (20,054) (1) The following table presents the reconciliation of total segment loss before income taxes to consolidated loss before income taxes for the periods presented (in thousands, unaudited): Three Months Ended Six Months Ended 2020 2019 2020 2019 Total segment loss before income taxes $ (61,132) $ (68,322) $ (213,742) $ (134,595) Corporate interest expense (33,458) (12,711) (62,740) (25,318) Corporate other income 4,430 9,056 13,821 17,911 Gain on partial extinguishment of 2021 Notes 6,391 — 6,391 — Consolidated loss before income taxes $ (83,769) $ (71,977) $ (256,270) $ (142,002)
Reconciliation of Segment Gross Profit and Loss	The following table presents the reconciliation of total segment loss before income taxes to consolidated loss before income taxes for the periods presented (in thousands, unaudited): Three Months Ended Six Months Ended 2020 2019 2020 2019 Total segment loss before income taxes $ (61,132) $ (68,322) $ (213,742) $ (134,595) Corporate interest expense (33,458) (12,711) (62,740) (25,318) Corporate other income 4,430 9,056 13,821 17,911 Gain on partial extinguishment of 2021 Notes 6,391 — 6,391 — Consolidated loss before income taxes $ (83,769) $ (71,977) $ (256,270) $ (142,002)

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurement Inputs and Valuation Techniques (Details) - IRLCs - Not Designated as Hedging Instrument	Jun. 30, 2020	Dec. 31, 2019
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value rates, IRLCs	0.40	0.56
Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value rates, IRLCs	1	1
Weighted average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value rates, IRLCs	0.70	0.78

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value of Cash Equivalents and Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale	$ 75,021	$ 36,507
Total	3,427,325	2,264,688
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale	0	0
Total	1,784,896	872,431
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale	75,021	36,507
Total	1,637,338	1,392,257
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale	0
Total	5,091
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,784,896	872,431
Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,784,896	872,431
Money market funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Money market funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		35,009
Short-term investments	465,715	862,154
U.S. government agency securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Short-term investments	0	0
U.S. government agency securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		35,009
Short-term investments	465,715	862,154
U.S. government agency securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		31,113
Short-term investments	14,972	150,267
Commercial paper | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Short-term investments	0	0
Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		31,113
Short-term investments	14,972	150,267
Commercial paper | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	70,189	6,441
Short-term investments	963,231	80,003
Treasury bills | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Treasury bills | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	70,189	6,441
Short-term investments	963,231	80,003
Treasury bills | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Short-term investments	0
Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		1,065
Short-term investments	30,213	159,431
Corporate notes and bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Short-term investments	0	0
Corporate notes and bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		1,065
Short-term investments	30,213	159,431
Corporate notes and bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		249
Short-term investments	498	1,245
Certificates of deposit | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Short-term investments	0	0
Certificates of deposit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		249
Short-term investments	498	1,245
Certificates of deposit | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	16,538	27,889
Municipal securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Municipal securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	16,538	27,889
Municipal securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
IRLCs | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	5,091	937
IRLCs | Level 1 | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
IRLCs | Level 2 | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	937
IRLCs | Level 3 | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	5,091
Forward contracts | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		7
Derivative liability	961	(60)
Forward contracts | Level 1 | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0
Derivative liability	0	0
Forward contracts | Level 2 | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		7
Derivative liability	961	$ (60)
Forward contracts | Level 3 | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Changes in IRLCs (Details) - IRLCs - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Derivative Asset, Rollforward [Roll Forward]
Balance, beginning of the period	$ 2,225	$ 937
Issuances	10,142	15,507
Transfers	(8,586)	(13,142)
Fair value changes recognized in earnings	1,310	1,789
Balance, end of period	$ 5,091	$ 5,091

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Mortgage Loans Held For Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount	$ 168.9	$ 34.3
IRLCs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount	$ 214.9	$ 64.7

Cash and Cash Equivalents, Sh_3

Cash and Cash Equivalents, Short-term Investments and Restricted Cash - Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Market Value of Cash and Cash Equivalents and Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents	$ 2,045,474	$ 1,141,263
Short-term investments:
Gross Unrealized Gains	2,088	526
Gross Unrealized Losses	(10)	(120)
Restricted cash	33,620	89,646
Cash, cash equivalents, short-term investments, and restricted cash, amortized cost	3,568,183	2,511,492
Cash, cash equivalents, short-term investments, and restricted cash, estimated fair market value	3,570,261	2,511,898
U.S. government agency securities
Short-term investments:
Amortized Cost	463,806	861,862
Gross Unrealized Gains	1,909	365
Gross Unrealized Losses	0	(73)
Estimated Fair Market Value	465,715	862,154
Corporate notes and bonds
Short-term investments:
Amortized Cost	30,094	159,382
Gross Unrealized Gains	119	91
Gross Unrealized Losses	0	(42)
Estimated Fair Market Value	30,213	159,431
Commercial paper
Short-term investments:
Amortized Cost	14,972	150,267
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Market Value	14,972	150,267
Treasury bills
Short-term investments:
Amortized Cost	963,200	79,989
Gross Unrealized Gains	41	14
Gross Unrealized Losses	(10)	0
Estimated Fair Market Value	963,231	80,003
Municipal securities
Short-term investments:
Amortized Cost	16,519	27,836
Gross Unrealized Gains	19	56
Gross Unrealized Losses	0	(3)
Estimated Fair Market Value	16,538	27,889
Certificates of deposit
Short-term investments:
Amortized Cost	498	1,245
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Market Value	498	1,245
Cash
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents	190,389	194,955
Money market funds
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents	1,784,896	872,431
U.S. government agency securities
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents, at cost		35,011
Cash and cash equivalents, gross unrealized losses		(2)
Cash and cash equivalents		35,009
Commercial paper
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents		31,113
Treasury bills
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents	$ 70,189	6,441
Corporate notes and bonds
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents		1,065
Certificates of deposit
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents		$ 249

Accounts Receivable, net (Detai

Accounts Receivable, net (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Receivables [Abstract]
Accounts receivable, net	$ 66,878		$ 67,005
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	4,522
Credit loss expense	1,614	$ 706
Less: write-offs, net of recoveries and other adjustments	(3,854)
Ending balance	$ 2,282	$ 2,282

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Work-in-process	$ 12,164	$ 152,171
Finished goods	123,237	684,456
Inventory	$ 135,401	$ 836,627

Contract Cost Assets (Details)

Contract Cost Assets (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract cost assets	$ 47,747,000		$ 47,747,000		$ 45,209,000
Impairment of contract cost assets	0	$ 0	0	$ 0
Amortization of contract cost assets	$ 8,700,000	$ 9,200,000	$ 17,070,000	$ 17,880,000

Property and Equipment, net - D

Property and Equipment, net - Detail of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment	$ 390,126	$ 345,490
Less: accumulated amortization and depreciation	(194,379)	(175,001)
Property and equipment, net	195,747	170,489
Website development costs
Property, Plant and Equipment [Line Items]
Property and equipment	157,468	149,648
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	107,139	81,981
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property and equipment	51,482	45,337
Office equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment	42,236	36,582
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 31,801	$ 31,942

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Property, Plant and Equipment [Line Items]
Amortization and depreciation expense related to property and equipment other than website development costs	$ 7.1	$ 6.4	$ 18.9	$ 12.4
Capitalization of website development costs	15.4	10.3	27.9	20.3
Amortization of website development costs and intangible assets included in technology and development	13.1	11	24.9	22
Technology and development | Software Development
Property, Plant and Equipment [Line Items]
Amortization of website development costs and intangible assets included in technology and development	$ 6	$ 3.6	$ 11.4	$ 7

Equity Investment - Additional

Equity Investment - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Oct. 31, 2016	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Non-cash impairment charge				$ 0	$ 0	$ 76,800	$ 0
Proceeds from sale of equity investment						10,000	$ 0
October 2016 Investment | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Percentage of equity interest held	10.00%		10.00%
Equity investments			$ 10,000
Non-cash impairment charge		$ 5,300
Fair value of investment	$ 4,700			4,700		4,700
Proceeds from sale of equity investment	$ 10,000
Gain on sale of investment				$ 5,300		$ 5,300

Intangible Assets, net - Intang

Intangible Assets, net - Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Cost	$ 348,050	$ 299,416
Accumulated Amortization	(241,060)	(216,849)
Net	106,990	82,567
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Cost	36,500
Accumulated Amortization	(1,274)
Net	35,226	108,000
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	102,600	102,600
Accumulated Amortization	(81,372)	(73,770)
Net	21,228	28,830
Developed technology
Finite-Lived Intangible Assets [Line Items]
Cost	107,200	107,200
Accumulated Amortization	(87,340)	(81,383)
Net	19,860	25,817
Software
Finite-Lived Intangible Assets [Line Items]
Cost	40,744	35,527
Accumulated Amortization	(25,031)	(20,843)
Net	15,713	14,684
Intangibles-in-progress
Finite-Lived Intangible Assets [Line Items]
Cost	10,054	6,391
Accumulated Amortization	0	0
Net	10,054	6,391
Purchased content
Finite-Lived Intangible Assets [Line Items]
Cost	50,552	47,298
Accumulated Amortization	(45,726)	(40,636)
Net	4,826	6,662
Lender licenses
Finite-Lived Intangible Assets [Line Items]
Cost	400	400
Accumulated Amortization	(317)	(217)
Net	$ 83	$ 183

Intangible Assets, net - Additi

Intangible Assets, net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Indefinite-lived Intangible Assets [Line Items]
Amortization of website development costs and intangible assets included in technology and development	$ 13,100		$ 11,000	$ 24,900	$ 22,000
Non-cash impairment charge				76,800	$ 0
Trade names and trademarks | Trulia
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible asset		$ 108,000
Non-cash impairment charge		71,500
Fair value of the intangible asset	$ 36,500	$ 36,500		$ 36,500
Useful life				10 years

Deferred Revenue (Details)

Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Change in Contract with Customer, Liability [Roll Forward]
Beginning balance	$ 35,347	$ 39,747
Deferral of revenue	222,895	476,624
Less: Revenue recognized	(213,728)	(471,857)
Ending balance	44,514	44,514
Revenue recognized, recorded in deferred revenue as of prior period	$ 33,800	$ 36,600

Debt - Schedule of Carrying Val

Debt - Schedule of Carrying Value of Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2020	May 19, 2020	May 15, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total	$ 2,007,010			$ 2,274,990
Convertible Debt
Debt Instrument [Line Items]
Convertible senior notes	$ 1,819,978			1,553,039
Convertible Debt | 1.375% convertible senior notes due 2026
Debt Instrument [Line Items]
Stated Interest Rate	1.375%
Convertible senior notes	$ 337,171			327,187
Convertible Debt | 2.75% convertible senior notes due 2025
Debt Instrument [Line Items]
Stated Interest Rate	2.75%	2.75%	2.75%
Convertible senior notes	$ 401,786			0
Convertible Debt | 0.75% convertible senior notes due 2024
Debt Instrument [Line Items]
Stated Interest Rate	0.75%
Convertible senior notes	$ 507,039			490,538
Convertible Debt | 1.50% convertible senior notes due 2023
Debt Instrument [Line Items]
Stated Interest Rate	1.50%
Convertible senior notes	$ 318,348			310,175
Convertible Debt | 2.00% convertible senior notes due 2021
Debt Instrument [Line Items]
Stated Interest Rate	2.00%
Convertible senior notes	$ 245,997			415,502
Convertible Debt | 2.75% convertible senior notes due 2020
Debt Instrument [Line Items]
Stated Interest Rate	2.75%
Convertible senior notes	$ 9,637			9,637
Mortgages Segment
Debt Instrument [Line Items]
Warehouse line of credit	69,814			30,427
Line of Credit | Homes Segment
Debt Instrument [Line Items]
Short-term debt	117,218			691,524
Goldman Sachs Bank USA | Line of Credit | Homes Segment
Debt Instrument [Line Items]
Short-term debt	19,632			39,244
Citibank, N.A. | Mortgages Segment
Debt Instrument [Line Items]
Short-term debt	33,918			394
Citibank, N.A. | Line of Credit | Homes Segment
Debt Instrument [Line Items]
Short-term debt	33,037			296,369
Credit Suisse AG, Cayman Islands | Line of Credit | Homes Segment
Debt Instrument [Line Items]
Short-term debt	64,549			355,911
Comerica Bank | Line of Credit | Mortgages Segment
Debt Instrument [Line Items]
Warehouse line of credit	$ 35,896			$ 30,033

Debt - Schedule of Credit Facil

Debt - Schedule of Credit Facilities (Details) - Homes Segment - Line of Credit	Jun. 30, 2020USD ($)
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 1,500,000,000
Goldman Sachs Bank USA | Final Maturity Date, April 20, 2022
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 500,000,000
Weighted Average Interest Rate	3.91%
Citibank, N.A. | Final Maturity Date, January 31, 2022
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 500,000,000
Weighted Average Interest Rate	4.69%
Credit Suisse AG, Cayman Islands | Final Maturity Date, July 31, 2021
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 500,000,000
Weighted Average Interest Rate	4.62%

Debt - Narrative (Detail)

Debt - Narrative (Detail)	May 15, 2020USD ($)day$ / sharesshares	Jun. 30, 2020USD ($)$ / shares	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)day$ / shares	Jun. 30, 2019USD ($)	May 19, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Increased inventory under credit facilities		$ 135,400,000		$ 135,400,000			$ 836,600,000
Increased borrowings under credit facilities		117,200,000		117,200,000			691,500,000
Gain on partial extinguishment		6,391,000	$ 0	6,391,000	$ 0
Class C Capital Stock
Debt Instrument [Line Items]
Shares received in unwinding of capped call transactions | shares	317,865
Value based on trading price of Class C capital stock at time of unwind	$ 14,800,000
Convertible Debt
Debt Instrument [Line Items]
Aggregate Principal Amount		2,386,717,000		2,386,717,000
Unamortized Debt Discount and Debt Issuance Costs		566,739,000		$ 566,739,000			463,348,000
2024 and 2026 Notes | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, threshold consecutive trading days | day				30
Debt Instrument, convertible threshold percentage				130.00%
2.75% convertible senior notes due 2025 | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, convertible threshold trading days | day	20
Debt instrument, threshold consecutive trading days | day	30
Debt Instrument, convertible threshold percentage	130.00%
Aggregate Principal Amount	$ 500,000,000	$ 565,000,000		$ 565,000,000		$ 65,000,000
Stated Interest Rate	2.75%	2.75%		2.75%		2.75%
Net proceeds from issuance	$ 553,300,000
Remaining consideration allocated to equity component	$ 154,800,000
Conversion Price per Share (usd per share) | $ / shares	$ 67.20	$ 67.20		$ 67.20
Unamortized Debt Discount and Debt Issuance Costs	$ 3,300,000	$ 163,214,000		$ 163,214,000			0
2.75% convertible senior notes due 2025 | Convertible Debt | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Repurchase price percentage of principal amount	100.00%
2.75% convertible senior notes due 2025 | Convertible Debt | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Repurchase price percentage of principal amount	100.00%
2.00% convertible senior notes due 2021 | Convertible Debt
Debt Instrument [Line Items]
Aggregate Principal Amount		$ 265,330,000		$ 265,330,000
Stated Interest Rate		2.00%		2.00%
Repurchased amount	$ 194,700,000
Cash paid for repurchase	194,700,000
Aggregate purchase price	230,900,000
Fair value of liability component	172,900,000
Remaining consideration allocated to equity component	58,000,000
Reduction to long-term debt	179,300,000
Reduction to additional paid-in capital	58,000,000
Gain on partial extinguishment	$ 6,400,000
Conversion Price per Share (usd per share) | $ / shares		$ 52.36		$ 52.36
Unamortized Debt Discount and Debt Issuance Costs		$ 19,333,000		$ 19,333,000			44,498,000
2.00% convertible senior notes due 2021 | Convertible Debt | Class C Capital Stock
Debt Instrument [Line Items]
Shares issued in debt conversion | shares	753,936
Citibank, N.A.
Debt Instrument [Line Items]
Repurchase agreement, committed amount		25,000,000		25,000,000
Citibank, N.A. | Mortgages Segment
Debt Instrument [Line Items]
Short-term debt		$ 33,918,000		$ 33,918,000			$ 394,000

Debt - Schedule of Warehouse Li

Debt - Schedule of Warehouse Lines of Credit (Details) - Line of Credit - Mortgages Segment	Jun. 30, 2020USD ($)
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 125,000,000
Citibank, N.A.
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 75,000,000
Weighted Average Interest Rate	1.88%
Comerica Bank
Debt Instrument [Line Items]
Maximum Borrowing Capacity	$ 50,000,000
Weighted Average Interest Rate	2.81%

Debt - Schedule of Convertible

Debt - Schedule of Convertible Senior Notes (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	May 19, 2020	May 15, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Interest Expense	$ 37,590,000	$ 18,897,000	$ 75,182,000	$ 35,363,000
Convertible Debt
Debt Instrument [Line Items]
Aggregate Principal Amount	2,386,717,000		2,386,717,000
Unamortized Debt Discount and Debt Issuance Costs	566,739,000		566,739,000				$ 463,348,000
Fair Value	3,054,058,000		3,054,058,000				2,304,376,000
Contractual Coupon Interest	8,259,000	3,768,000	14,994,000	7,536,000
Accretion of bond discount	23,859,000	8,173,000	45,152,000	16,201,000
Amortization of Debt Issuance Costs	1,340,000	826,000	2,594,000	1,637,000
Interest Expense	33,458,000	12,767,000	62,740,000	25,374,000
Convertible Debt | 1.375% convertible senior notes due 2026
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 500,000,000		$ 500,000,000
Stated Interest Rate	1.375%		1.375%
Effective Interest Rate	8.10%		8.10%
Unamortized Debt Discount and Debt Issuance Costs	$ 162,829,000		$ 162,829,000				172,813,000
Fair Value	705,000,000		705,000,000				597,380,000
Contractual Coupon Interest	1,719,000	0	3,438,000	0
Accretion of bond discount	4,922,000	0	9,746,000	0
Amortization of Debt Issuance Costs	120,000	0	238,000	0
Interest Expense	6,761,000	0	13,422,000	0
Convertible Debt | 2.75% convertible senior notes due 2025
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 565,000,000		$ 565,000,000		$ 65,000,000	$ 500,000,000
Stated Interest Rate	2.75%		2.75%		2.75%	2.75%
Effective Interest Rate	10.32%		10.32%
Unamortized Debt Discount and Debt Issuance Costs	$ 163,214,000		$ 163,214,000			$ 3,300,000	0
Fair Value	659,756,000		659,756,000				0
Contractual Coupon Interest	2,007,000	0	2,007,000	0
Accretion of bond discount	3,148,000	0	3,148,000	0
Amortization of Debt Issuance Costs	168,000	0	168,000	0
Interest Expense	5,323,000	0	5,323,000	0
Convertible Debt | 0.75% convertible senior notes due 2024
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 673,000,000		$ 673,000,000
Stated Interest Rate	0.75%		0.75%
Effective Interest Rate	7.68%		7.68%
Unamortized Debt Discount and Debt Issuance Costs	$ 165,961,000		$ 165,961,000				182,462,000
Fair Value	957,659,000		957,659,000				819,378,000
Contractual Coupon Interest	1,262,000	0	2,510,000	0
Accretion of bond discount	8,095,000	0	15,956,000	0
Amortization of Debt Issuance Costs	278,000	0	545,000	0
Interest Expense	9,635,000	0	19,011,000	0
Convertible Debt | 1.50% convertible senior notes due 2023
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 373,750,000		$ 373,750,000
Stated Interest Rate	1.50%		1.50%
Effective Interest Rate	6.99%		6.99%
Unamortized Debt Discount and Debt Issuance Costs	$ 55,402,000		$ 55,402,000				63,575,000
Fair Value	388,113,000		388,113,000				356,464,000
Contractual Coupon Interest	1,402,000	1,402,000	2,804,000	2,804,000
Accretion of bond discount	3,749,000	3,496,000	7,446,000	6,933,000
Amortization of Debt Issuance Costs	366,000	342,000	727,000	678,000
Interest Expense	5,517,000	5,240,000	10,977,000	10,415,000
Convertible Debt | 2.00% convertible senior notes due 2021
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 265,330,000		$ 265,330,000
Stated Interest Rate	2.00%		2.00%
Effective Interest Rate	7.43%		7.43%
Unamortized Debt Discount and Debt Issuance Costs	$ 19,333,000		$ 19,333,000				44,498,000
Fair Value	326,688,000		326,688,000				514,312,000
Contractual Coupon Interest	1,803,000	2,300,000	4,103,000	4,600,000
Accretion of bond discount	3,945,000	4,677,000	8,856,000	9,268,000
Amortization of Debt Issuance Costs	408,000	484,000	916,000	959,000
Interest Expense	6,156,000	7,461,000	13,875,000	14,827,000
Convertible Debt | 2.75% convertible senior notes due 2020
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 9,637,000		$ 9,637,000
Stated Interest Rate	2.75%		2.75%
Unamortized Debt Discount and Debt Issuance Costs	$ 0		$ 0				0
Fair Value	16,842,000		16,842,000				$ 16,842,000
Contractual Coupon Interest	66,000	66,000	132,000	132,000
Accretion of bond discount	0	0	0	0
Amortization of Debt Issuance Costs	0	0	0	0
Interest Expense	$ 66,000	$ 66,000	$ 132,000	$ 132,000

Debt - Summary of Conversion an

Debt - Summary of Conversion and Redemption Options and Details Related to Capped Call Confirmations (Details) - Convertible Debt	6 Months Ended
	Jun. 30, 2020$ / shares	May 15, 2020$ / shares
1.375% convertible senior notes due 2026
Debt Instrument [Line Items]
Debt instrument, conversion rate shares	0.0229830
Conversion Price per Share (usd per share)	$ 43.51
Initial cap price (usd per share)	$ 80.5750
Cap Price Premium	150.00%
2.75% convertible senior notes due 2025
Debt Instrument [Line Items]
Debt instrument, conversion rate shares	0.0148810
Conversion Price per Share (usd per share)	$ 67.20	$ 67.20
0.75% convertible senior notes due 2024
Debt Instrument [Line Items]
Debt instrument, conversion rate shares	0.0229830
Conversion Price per Share (usd per share)	$ 43.51
Initial cap price (usd per share)	$ 72.5175
Cap Price Premium	125.00%
1.50% convertible senior notes due 2023
Debt Instrument [Line Items]
Debt instrument, conversion rate shares	0.0127592
Conversion Price per Share (usd per share)	$ 78.37
Initial cap price (usd per share)	$ 105.45
Cap Price Premium	85.00%
2.00% convertible senior notes due 2021
Debt Instrument [Line Items]
Debt instrument, conversion rate shares	0.0190985
Conversion Price per Share (usd per share)	$ 52.36
Initial cap price (usd per share)	$ 69.19
Cap Price Premium	85.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule Of Income Tax [Line Items]
Income tax benefit (expense)	$ (679)		$ 0	$ 8,549	$ 2,500
Non-cash impairment charge				76,800	$ 0
Trulia | Trade names and trademarks
Schedule Of Income Tax [Line Items]
Income tax benefit (expense)				$ 9,700
Non-cash impairment charge		$ 71,500
Federal
Schedule Of Income Tax [Line Items]
Net operating loss carryforwards						$ 1,137,600
State
Schedule Of Income Tax [Line Items]
Net operating loss carryforwards						$ 34,300

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands	May 19, 2020shares	May 15, 2020USD ($)$ / sharesshares	Jun. 30, 2020USD ($)shares	Jun. 30, 2020USD ($)Voteshares	Dec. 31, 2019shares
Class of Stock [Line Items]
Preferred stock, issued (in shares)			0	0	0
Preferred stock, outstanding (in shares)			0	0	0
Value of capital stock issuance | $			$ 411,523	$ 411,523
Over-Allotment Option
Class of Stock [Line Items]
Shares issued and sold (in shares)	800,000
Class A Common Stock
Class of Stock [Line Items]
Common stock holders voting right | Vote				1
Conversion of common stock conversion ratio				1
Class B Common Stock
Class of Stock [Line Items]
Common stock holders voting right | Vote				10
Class C Capital Stock
Class of Stock [Line Items]
Shares issued and sold (in shares)		8,000,000
Shares issued		753,936
Shares issued (usd per share) | $ / shares		$ 48
Value of capital stock issuance | $		$ 36,200
Shares received in unwinding of capped call transactions		317,865
Value based on trading price of Class C capital stock at time of unwind | $		$ 14,800
Class C Capital Stock | Public Stock Offering
Class of Stock [Line Items]
Shares issued and sold (in shares)		8,800,000
Public offering price (usd per share) | $ / shares		$ 48
Net proceeds from public offering | $		$ 411,500

Share-Based Awards - Additional

Share-Based Awards - Additional Information (Details) - 2020 Plan - shares	Jun. 09, 2020	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	12,400,000
Increase in number of shares of common and capital stock available for issuance, percentage	5.00%
Exercise price per share fixed	100.00%
Share based compensation arrangement by share based payment, award minimum exercisable period		3 months
Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment, award maximum exercisable period		12 months
Expiration period		10 years
Vesting percentage		25.00%
Option Awards | Vesting, Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		12 months
Option Awards | Vesting, Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Option Awards | Vesting, Option Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Restricted Stock Units | Vesting, Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		12 months
Restricted Stock Units | Vesting, Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Restricted Stock Units | Vesting, Option Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years

Share-Based Awards - Summary of

Share-Based Awards - Summary of Option Award (Detail) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Number of Shares Subject to Existing Options
Beginning Balance (in shares) | shares	29,634,296
Granted (in shares) | shares	4,833,605
Exercised (in shares) | shares	(6,324,858)
Forfeited or cancelled (in shares) | shares	(674,462)
Ending Balance (in shares) | shares	27,468,581	29,634,296
Vested and exercisable ending balance (in shares) | shares	14,708,916
Weighted- Average Exercise Price Per Share
Beginning Balance (usd per share) | $ / shares	$ 35.95
Granted (usd per share) | $ / shares	49.24
Exercised (usd per share) | $ / shares	29.25
Forfeited or cancelled (usd per share) | $ / shares	40.76
Ending Balance (usd per share) | $ / shares	39.71	$ 35.95
Vested and exercisable (usd per share) | $ / shares	$ 35.84
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-Average Remaining Contractual Life, Outstanding	6 years 8 months 26 days	6 years 3 months 10 days
Weighted-Average Remaining Contractual Life, Vested and exercisable	4 years 11 months 15 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract]
Aggregate Intrinsic Value, Outstanding | $	$ 493,801	$ 331,107
Aggregate Intrinsic Value Vested, and exercisable | $	$ 320,951

Share-Based Awards - Fair Value

Share-Based Awards - Fair Value of Options Granted, Estimated at Date of Grant Using Black Scholes Merton Option Pricing Model (Detail) - Option Awards - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	51.00%	45.00%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate	0.33%	2.00%
Weighted-average expected life	5 years	5 years
Weighted-average fair value of options granted (usd per share)	$ 20.21	$ 16.96	$ 20.69	$ 16.79
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			45.00%	45.00%
Risk-free interest rate			0.33%	2.00%
Weighted-average expected life			5 years	4 years 9 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			51.00%	47.00%
Risk-free interest rate			0.93%	2.53%
Weighted-average expected life			5 years 6 months	5 years 3 months

Share-Based Awards - Option Awa

Share-Based Awards - Option Awards - Additional Information (Detail) $ in Millions	Jun. 30, 2020USD ($)
Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized cost of unvested share-based compensation awards	$ 218.2

Share-Based Awards - Summary _2

Share-Based Awards - Summary of Restricted Stock Units Activity (Detail) - Restricted Stock Units	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Restricted Stock Units
Beginning balance (in shares) | shares	7,052,767
Granted (in shares) | shares	3,665,016
Vested (in shares) | shares	(1,414,158)
Forfeited or cancelled (in shares) | shares	(513,401)
Ending balance (in shares) | shares	8,790,224
Weighted- Average Grant- Date Fair Value
Unvested outstanding, beginning balance (usd per share) | $ / shares	$ 40.01
Granted (usd per share) | $ / shares	49.30
Vested (usd per share) | $ / shares	40.65
Forfeited or cancelled (usd per share) | $ / shares	41.62
Unvested outstanding, ending balance (usd per share) | $ / shares	$ 43.69

Share-Based Awards - Restricted

Share-Based Awards - Restricted Stock Units - Additional Information (Detail) $ in Millions	Jun. 30, 2020USD ($)
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 356.6

Share-Based Awards - Effects of

Share-Based Awards - Effects of Share Based Compensation in Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation	$ 52,351	$ 43,632	$ 96,146	$ 109,756
Chief Executive Officer
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation			26,400
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation	1,119	936	2,292	1,816
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation	9,116	6,801	16,109	12,451
Technology and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation	21,666	18,399	40,583	33,908
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation	$ 20,450	$ 17,496	$ 37,162	$ 61,581

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	May 15, 2020
September 1, 2026 | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			11,492
Conversion Price per Share (usd per share)	$ 43.51		$ 43.51
May 15, 2025 | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			8,408
Conversion Price per Share (usd per share)	67.20		$ 67.20		$ 67.20
September 1, 2024 | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			15,468
Conversion Price per Share (usd per share)	43.51		$ 43.51
July 1, 2023 | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			4,769
Conversion Price per Share (usd per share)	78.37		$ 78.37
December 1, 2021 | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			5,067
Conversion Price per Share (usd per share)	$ 52.36		$ 52.36
Class A Common Stock and Class C Capital Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	41,920	27,143	38,719	26,615
Class A Common Stock and Class C Capital Stock | Weighted average | Option Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	25,202	19,502	22,649	19,656
Class A Common Stock and Class C Capital Stock | Weighted average | Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	9,086	7,230	8,354	6,548
Class A Common Stock | December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	400	411	400	411
Class C Capital Stock | December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	7,232	0	7,316	0

Commitments and Contingencies -

Commitments and Contingencies - Purchase Commitments for Content Related to Mobile Applications and Websites (Details) $ in Thousands	Jun. 30, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 8,254
2021	17,627
2022	3,043
2023	507
Total future purchase commitments	$ 29,431

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Detail)	Jun. 20, 2017USD ($)	Feb. 09, 2017USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Jun. 30, 2018claim	Feb. 28, 2018claim	Feb. 05, 2018claim
Other Commitments [Line Items]
Outstanding letters of credit			$ 16,900,000
Outstanding surety bonds			9,800,000	$ 10,200,000
VHT Vs Zillow Group Inc.
Other Commitments [Line Items]
Jury awarded damages	$ 4,100,000
VHT Vs Zillow Group Inc. | Actual Damages
Other Commitments [Line Items]
Jury awarded damages		$ 79,875
VHT Vs Zillow Group Inc. | Statutory Damages
Other Commitments [Line Items]
Jury awarded damages		$ 8,200,000
Class Action Lawsuits
Other Commitments [Line Items]
Number of pending claims | claim					2
Shareholder Derivative Lawsuits
Other Commitments [Line Items]
Number of pending claims | claim						4	2
Homes under contract to purchase that have not closed
Other Commitments [Line Items]
Value of homes under contract that have not closed			$ 51,900,000

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - Zillow Merger - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Contribution Plan Disclosure [Line Items]
Company's contribution based on employee contribution (up to)			4.00%
Company's expense related to its defined contribution 401(k) retirement plans	$ 6.4	$ 5.2	$ 12.8	$ 10.1

Segment Information and Reven_3

Segment Information and Revenue - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2020Segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information and Reven_4

Segment Information and Revenue - Revenue Categories (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Revenue:
Total revenue	$ 768,352		$ 599,578		$ 1,894,173	$ 1,053,682
Costs and expenses:
Cost of revenue	461,071	[1]	271,221	[1]	1,222,743	422,569
Sales and marketing	155,598		187,433		360,246	349,020
Technology and development	128,857		120,330		263,775	228,100
General and administrative	85,511		82,839		177,796	178,613
Impairment costs	0		0		76,800	0
Integration costs	0		293		0	645
Total costs and expenses	831,037		662,116		2,101,360	1,178,947
Loss from operations	(62,685)		(62,538)		(207,187)	(125,265)
Other income	10,115		9,458		19,708	18,626
Interest expense	(37,590)		(18,897)		(75,182)	(35,363)
Loss before income taxes	(83,769)		(71,977)		(256,270)	(142,002)
Homes
Revenue:
Total revenue	454,252		248,924		1,224,125	377,396
Costs and expenses:
Cost of revenue	431,788	[1]	240,732	[1]	1,163,987	363,151
Sales and marketing	47,877		37,409		119,466	58,271
Technology and development	28,918		18,198		61,456	30,479
General and administrative	21,902		17,808		45,323	32,165
Impairment costs					0	0
Integration costs	0		0		0	0
Total costs and expenses	530,485		314,147		1,390,232	484,066
Loss from operations	(76,233)		(65,223)		(166,107)	(106,670)
Other income	0		0		0	0
Interest expense	(3,825)		(5,899)		(11,909)	(9,657)
Loss before income taxes	(80,058)		(71,122)		(178,016)	(116,327)
Homes | Zillow Offers
Revenue:
Total revenue	453,816		248,924		1,222,928	377,396
Homes | Premier Agent
Revenue:
Total revenue	0		0		0	0
Homes | Other
Revenue:
Total revenue	436		0		1,197	0
Homes | Mortgages
Revenue:
Total revenue	0		0		0	0
IMT
Revenue:
Total revenue	280,339		323,669		611,005	621,941
Costs and expenses:
Cost of revenue	23,387	[1]	26,059	[1]	47,705	50,310
Sales and marketing	96,026		135,440		216,199	262,094
Technology and development	93,176		94,261		188,204	182,230
General and administrative	53,884		54,671		112,638	125,521
Impairment costs					73,900	0
Integration costs	0		0		0	0
Total costs and expenses	266,473		310,431		638,646	620,155
Loss from operations	13,866		13,238		(27,641)	1,786
Other income	5,300		0		5,300	0
Interest expense	0		0		0	0
Loss before income taxes	19,166		13,238		(22,341)	1,786
IMT | Zillow Offers
Revenue:
Total revenue	0		0		0	0
IMT | Premier Agent
Revenue:
Total revenue	191,962		231,961		434,068	449,696
IMT | Other
Revenue:
Total revenue	88,377		91,708		176,937	172,245
IMT | Mortgages
Revenue:
Total revenue	0		0		0	0
Mortgages Segment
Revenue:
Total revenue	33,761		26,985		59,043	54,345
Costs and expenses:
Cost of revenue	5,896	[1]	4,430	[1]	11,051	9,108
Sales and marketing	11,695		14,584		24,581	28,655
Technology and development	6,763		7,871		14,115	15,391
General and administrative	9,725		10,360		19,835	20,927
Impairment costs					2,900	0
Integration costs	0		293		0	645
Total costs and expenses	34,079		37,538		72,482	74,726
Loss from operations	(318)		(10,553)		(13,439)	(20,381)
Other income	385		402		587	715
Interest expense	(307)		(287)		(533)	(388)
Loss before income taxes	(240)		(10,438)		(13,385)	(20,054)
Mortgages Segment | Zillow Offers
Revenue:
Total revenue	0		0		0	0
Mortgages Segment | Premier Agent
Revenue:
Total revenue	0		0		0	0
Mortgages Segment | Other
Revenue:
Total revenue	0		0		0	0
Mortgages Segment | Mortgages
Revenue:
Total revenue	$ 33,761		$ 26,985		$ 59,043	$ 54,345
[1]	Amortization of website development costs and intangible assets included in technology and development of $18,857 and $14,656 for the three months ended June 30, 2020 and 2019, respectively and $36,041 and $29,056 for the six months ended June 30, 2020 and 2019, respectively.

Segment Information and Reven_5

Segment Information and Revenue - Reconciliation of Segment Gross Profit and Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting, Revenue Reconciling Item [Line Items]
Loss before income taxes	$ (83,769)	$ (71,977)	$ (256,270)	$ (142,002)
Corporate interest expense	(37,590)	(18,897)	(75,182)	(35,363)
Corporate other income	10,115	9,458	19,708	18,626
Gain on partial extinguishment of 2021 Notes	6,391	0	6,391	0
Consolidated loss before income taxes	(83,769)	(71,977)	(256,270)	(142,002)
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Loss before income taxes	(61,132)	(68,322)	(213,742)	(134,595)
Consolidated loss before income taxes	(61,132)	(68,322)	(213,742)	(134,595)
Corporate
Segment Reporting, Revenue Reconciling Item [Line Items]
Corporate interest expense	(33,458)	(12,711)	(62,740)	(25,318)
Corporate other income	$ 4,430	$ 9,056	$ 13,821	$ 17,911