Guardant Health (GH) 10-K 24 Feb 22 2021 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2021	Feb. 18, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38683
Entity Registrant Name	GUARDANT HEALTH, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-4139254
Entity Address, Address Line One	505 Penobscot Dr.
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94063
City Area Code	855
Local Phone Number	698-8887
Title of 12(b) Security	Common Stock, par value $0.00001
Trading Symbol	GH
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 12.1
Entity Common Stock, Shares Outstanding		101,865,838
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement relating to its annual meeting of stockholders to be held in 2022, or the 2022 Annual Meeting, to be filed with the Securities and Exchange Commission, or the SEC, within 120 days after the end of the fiscal year to which this Annual Report on Form 10-K relates, are incorporated herein by reference where indicated. Except with respect to information specifically incorporated by reference in this Annual Report on Form 10-K, such proxy statement is not deemed to be filed as part hereof.
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Central Index Key	0001576280

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Audit Information [Abstract]
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	Redwood City, California

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents		$ 492,202	$ 832,977
Short-term marketable securities		440,546	961,903
Accounts receivable, net		97,652	53,299
Inventory		30,674	22,716
Prepaid expenses and other current assets, net		53,052	17,466
Total current assets		1,114,126	1,888,361
Long-term marketable securities		698,034	246,597
Property and equipment, net		124,461	62,782
Right-of-use assets		189,443	37,343
Intangible assets, net		14,207	16,155
Goodwill		3,290	3,290
Other assets, net		60,938	17,253
Total Assets	[1]	2,204,499	2,271,781
Current liabilities:
Accounts payable		17,580	7,340
Accrued compensation		42,496	28,280
Accrued expenses		45,285	22,639
Noncontrolling interest liability		78,000	0
Deferred revenue		11,326	8,550
Total current liabilities		194,687	66,809
Convertible senior notes, net		1,134,821	806,292
Long-term operating lease liabilities		226,053	41,565
Other long-term liabilities		3,933	1,520
Total Liabilities	[1]	1,559,494	916,186
Commitments and contingencies
Redeemable noncontrolling interest		0	57,100
Stockholders’ equity:
Preferred stock, par value of $0.00001 per share; 10,000,000 shares authorized, no shares issued and outstanding as of December 31, 2021 and 2020		0	0
Common stock, par value of $0.00001 per share; 350,000,000 shares authorized as of December 31, 2021 and 2020; 101,767,446 and 100,213,985 shares issued and outstanding as of December 31, 2021 and 2020, respectively		1	1
Additional paid-in capital		1,657,593	1,902,389
Accumulated other comprehensive (loss) income		(4,764)	2,697
Accumulated deficit		(1,007,825)	(606,592)
Total Stockholders’ Equity		645,005	1,298,495
Total Liabilities, Redeemable Noncontrolling Interest and Stockholders’ Equity		$ 2,204,499	$ 2,271,781
[1]	As of December 31, 2021 and 2020, this balance includes $20.4 million and $35.0 million of assets, respectively, that can be used only to settle obligations of the consolidated variable interest entity, or VIE, and VIE’s subsidiaries, and $4.3 million and $4.9 million of liabilities of the consolidated VIE and VIE’s subsidiaries, respectively, for which their creditors do not have recourse to the general credit of the Company. See Note 3, Investment in Joint Venture.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Preferred stock, par value (in usd per share)		$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)		10,000,000	10,000,000
Preferred stock, shares issued (in shares)		0	0
Preferred stock, shares outstanding (in shares)		0	0
Common stock, par value (in usd per share)		$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)		350,000,000	350,000,000
Common stock, shares outstanding (in shares)		101,767,446	100,213,985
Common stock, shares issued (in shares)		101,767,446	100,213,985
Variable interest entity, assets	[1]	$ 2,204,499	$ 2,271,781
Variable interest entity, liabilities	[1]	1,559,494	916,186
VIE, primary beneficiary
Variable interest entity, assets		20,400	35,000
Variable interest entity, liabilities		$ 4,300	$ 4,900
[1]	As of December 31, 2021 and 2020, this balance includes $20.4 million and $35.0 million of assets, respectively, that can be used only to settle obligations of the consolidated variable interest entity, or VIE, and VIE’s subsidiaries, and $4.3 million and $4.9 million of liabilities of the consolidated VIE and VIE’s subsidiaries, respectively, for which their creditors do not have recourse to the general credit of the Company. See Note 3, Investment in Joint Venture.

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue:
Precision oncology testing	$ 304,312	$ 236,324	$ 180,462
Development services and other	69,341	50,406	33,913
Total revenue	373,653	286,730	214,375
Costs and operating expenses:
Cost of precision oncology testing	110,396	74,769	62,255
Cost of development services and other	12,516	17,766	8,465
Research and development expense	263,221	149,862	86,292
Sales and marketing expense	191,881	106,513	78,335
General and administrative expense	206,640	192,770	61,399
Total costs and operating expenses	784,654	541,680	296,746
Loss from operations	(411,001)	(254,950)	(82,371)
Interest income	3,930	10,171	13,741
Interest expense	(2,577)	(4,766)	(1,181)
Other income	25,178	3,641	88
Loss before provision for income taxes	(384,470)	(245,904)	(69,723)
Provision for (benefit from) income taxes	300	379	(1,872)
Net loss	(384,770)	(246,283)	(67,851)
Adjustment of redeemable noncontrolling interest	(20,900)	(7,500)	(7,800)
Net loss attributable to Guardant Health, Inc. common stockholders - basic	(405,670)	(253,783)	(75,651)
Net loss attributable to Guardant Health, Inc. common stockholders - diluted	$ (405,670)	$ (253,783)	$ (75,651)
Net loss per share attributable to Guardant Health, Inc. common stockholders, basic (in usd per share)	$ (4)	$ (2.60)	$ (0.84)
Net loss per share attributable to Guardant Health, Inc. common stockholders, diluted (in usd per share)	$ (4)	$ (2.60)	$ (0.84)
Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, basic (in shares)	101,314	97,504	90,597
Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, diluted (in shares)	101,314	97,504	90,597

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (384,770)	$ (246,283)	$ (67,851)
Other comprehensive income (loss), net of tax impact:
Unrealized (loss) gain on available-for-sale securities	(5,769)	1,131	1,110
Foreign currency translation adjustments	(1,692)	455	84
Other comprehensive income	(7,461)	1,586	1,194
Comprehensive loss	(392,231)	(244,697)	(66,657)
Comprehensive loss attributable to redeemable noncontrolling interest	(20,900)	(7,500)	(7,800)
Comprehensive loss attributable to Guardant Health, Inc.	$ (413,131)	$ (252,197)	$ (74,457)

Consolidated Statements of Rede

Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative effect adjustment	Common Stock	Additional Paid-in Capital	Additional Paid-in CapitalCumulative effect adjustment	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit	Accumulated DeficitCumulative effect adjustment	Redeemable Noncontrolling Interest
Beginning balance at Dec. 31, 2018									$ 41,800
Increase (Decrease) in Temporary Equity [Roll Forward]
Adjustment of redeemable noncontrolling interest	$ (7,800)						$ (7,800)		7,800
Ending balance at Dec. 31, 2019									49,600
Beginning balance (in shares) at Dec. 31, 2018			85,832,454
Beginning balance at Dec. 31, 2018	483,152		$ 1	$ 764,033		$ (83)	(280,799)
Beginning balance (Cumulative effect adjustment for Topic 606 adoption) at Dec. 31, 2018	4,907						4,907
Beginning balance (Cumulative effect adjustment for ASU 2018-07 adoption) at Dec. 31, 2018	0			1,266			(1,266)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon follow-on offering, net of offering costs (in shares)			5,175,000
Issuance of common stock upon follow-on offering, net of offering costs	$ 349,709			349,709
Issuance of common stock upon exercise of stock options (in shares)	2,999,419		2,999,419
Issuance of common stock upon exercise of stock options	$ 11,638			11,638
Vesting of restricted stock units (in shares)			22,208
Vesting of common stock exercised early	95			95
Common stock issued under employee stock purchase plan (in shares)			232,333
Common stock issued under employee stock purchase plan	6,395			6,395
Stock-based compensation	16,954			16,954
Other comprehensive gain (loss), net of tax impact	1,194					1,194
Net loss	(67,851)						(67,851)
Ending balance (in shares) at Dec. 31, 2019			94,261,414
Ending balance at Dec. 31, 2019	$ 798,393		$ 1	1,150,090		1,111	(352,809)
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2020-06 [Member]
Increase (Decrease) in Temporary Equity [Roll Forward]
Adjustment of redeemable noncontrolling interest	$ (7,500)						(7,500)		7,500
Ending balance at Dec. 31, 2020									57,100
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon follow-on offering, net of offering costs (in shares)			4,312,500
Issuance of common stock upon follow-on offering, net of offering costs	354,600			354,600
Equity component of convertible senior notes, net	330,403			330,403
Purchase of convertible senior note hedges	$ (90,045)			(90,045)
Issuance of common stock upon exercise of stock options (in shares)	1,446,843		1,446,843
Issuance of common stock upon exercise of stock options	$ 9,528			9,528
Vesting of restricted stock units (in shares)			97,188
Vesting of common stock exercised early	52			52
Common stock issued under employee stock purchase plan (in shares)			96,040
Common stock issued under employee stock purchase plan	7,095			7,095
Taxes paid related to net share settlement of restricted stock units	(3,447)			(3,447)
Stock-based compensation	144,113			144,113
Other comprehensive gain (loss), net of tax impact	1,586					1,586
Net loss	(246,283)						(246,283)
Ending balance (in shares) at Dec. 31, 2020			100,213,985
Ending balance at Dec. 31, 2020	1,298,495	$ (325,966)	$ 1	1,902,389	$ (330,403)	2,697	(606,592)	$ 4,437
Increase (Decrease) in Temporary Equity [Roll Forward]
Adjustment of redeemable noncontrolling interest	(20,900)						(20,900)		20,900
Reclassification of redeemable noncontrolling interest to noncontrolling interest liability									(78,000)
Ending balance at Dec. 31, 2021									$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of convertible senior note hedges	$ (90,000)
Issuance of common stock upon exercise of stock options (in shares)	693,074		693,074
Issuance of common stock upon exercise of stock options	$ 8,112			8,112
Vesting of restricted stock units (in shares)			750,160
Vesting of common stock exercised early	52			52
Common stock issued under employee stock purchase plan (in shares)			110,227
Common stock issued under employee stock purchase plan	9,753			9,753
Taxes paid related to net share settlement of restricted stock units	(83,759)			(83,759)
Stock-based compensation	151,449			151,449
Other comprehensive gain (loss), net of tax impact	(7,461)					(7,461)
Net loss	(384,770)						(384,770)
Ending balance (in shares) at Dec. 31, 2021			101,767,446
Ending balance at Dec. 31, 2021	$ 645,005		$ 1	$ 1,657,593		$ (4,764)	$ (1,007,825)

Consolidated Statements of Re_2

Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 1,130	$ 723

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
OPERATING ACTIVITIES:
Net loss	$ (384,770)	$ (246,283)	$ (67,851)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	22,271	16,065	11,411
Non-cash operating lease costs	24,661	5,567	4,409
Charge of in-process research and development costs with no alternative future use	0	8,500	0
Unrealized translation gains on obligation related to royalty	0	0	(147)
Re-valuation of contingent consideration	2,380	(120)	300
Non-cash stock-based compensation	151,449	144,113	16,954
Amortization of debt discount and debt issuance costs	2,564	4,729	0
Amortization of premium (discount) on marketable securities	12,849	4,016	(2,310)
Benefit from income tax differences	0	0	(1,597)
Credit loss adjustment and others	47	7,151	0
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	(44,353)	(5,463)	(7,389)
Inventory	(7,957)	(7,535)	(6,045)
Prepaid expenses and other current assets	(35,753)	(6,077)	(6,185)
Other assets	(4,182)	(19,326)	(2,852)
Accounts payable	8,638	(7,859)	4,341
Accrued compensation	14,216	9,723	5,571
Accrued expenses and other current liabilities	11,942	(1,359)	9,289
Operating lease liabilities	14,205	(6,042)	(1,172)
Deferred revenue	2,776	(3,727)	(3,861)
Net cash used in operating activities	(209,017)	(103,927)	(47,134)
INVESTING ACTIVITIES:
Purchase of marketable securities	(900,808)	(1,125,575)	(614,290)
Maturity of marketable securities	952,110	562,548	325,333
Purchase of non-marketable equity and other related investments	(39,422)	0	0
Business acquisition, net of cash acquired	0	0	(7,328)
Purchase of property and equipment	(75,035)	(36,173)	(18,717)
Purchase of intangible assets and capitalized license obligations	0	(17,886)	(2,500)
Payment in connection with a license agreement	0	0	(68)
Net cash used in investing activities	(63,155)	(617,086)	(317,570)
FINANCING ACTIVITIES:
Payments made on royalty obligations	0	0	(311)
Payments made on finance lease obligations	(146)	(174)	(127)
Proceeds from issuance of common stock under employee stock purchase plan	9,753	7,095	6,395
Proceeds from issuance of common stock upon exercise of stock options	8,112	9,528	11,638
Taxes paid related to net share settlement of restricted stock units	(83,759)	(3,447)	0
Proceeds from public offerings of common stock	0	355,730	350,432
Payment of offering costs related to public offerings of common stock	0	(1,130)	(723)
Proceeds from borrowings on convertible senior notes, net	0	1,132,750	0
Payment of offering costs related to borrowings on convertible senior notes	(784)	0	0
Purchase of convertible note hedges	0	(90,045)	0
Net cash (used in) provided by financing activities	(66,824)	1,410,307	367,304
Net effect of foreign exchange rate changes on cash, cash equivalents, and restricted cash	(1,693)	455	84
Net increase in cash, cash equivalents and restricted cash	(340,689)	689,749	2,684
Cash, cash equivalents and restricted cash – Beginning of period	832,977	143,228	140,544
Cash, cash equivalents and restricted cash – End of period	492,288	832,977	143,228
Supplemental Disclosures of Cash Flow Information:
Operating lease liabilities arising from obtaining right-of-use assets	171,382	13,123	16,714
Cash paid for interest	0	0	1,181
Cash paid for income taxes	393	331	298
Supplemental Disclosures of Noncash Investing and Financing Activities:
Purchases of property and equipment included in accounts payable and accrued expenses	8,892	1,986	4,818
Property and equipment acquired under finance leases	238	47	0
Vesting of common stock exercised early	52	52	95
Reclassification of redeemable noncontrolling interest to noncontrolling interest liability	78,000	0	0
Initial fair value of contingent consideration at acquisition date	0	0	1,065
Debt issuance costs included in accounts payable and accrued expenses	$ 0	$ 784	$ 0

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Guardant Health, Inc., or the Company, is a leading precision oncology company focused on helping conquer cancer globally through use of its proprietary tests, vast data sets and advanced analytics. Today the Company's proprietary tests are helping to realize the full potential of precision oncology by providing patients and their doctors critical insights that can inform decisions at all stages of the disease, from screening, to monitoring cancer recurrence, to treatment decisions. The key to conquering cancer is unprecedented access to its molecular information throughout all stages of the disease, which the Company enables by its tests. By looking at the unique dimensions of cancer found in blood, including genomic alterations, methylation, and fragmentomics, the Company is unlocking insights that can increasingly help patients across all stages of cancer, including at its earliest, when it’s most treatable. To help identify cancer at the earliest stages, the Company is developing Guardant SHIELD, a blood test for cancer screening in average-risk adults without symptoms, that detects very early signs of cancer by interrogating genomic alterations, methylation, and fragmentomic signals from a simple blood draw. In pursuit of its goal to manage cancer across all stages of the disease, the Company provides its Guardant360, Guardant360 LDT, Guardant 360 CDx, and GuardantOMNI liquid biopsy-based tests for advanced stage cancer. In February 2021, the Company launched its Guardant Reveal liquid biopsy-based tests for residual and recurring cancer to first address the need in Stage II-III colorectal cancer. In June 2021, the Company launched Guardant360 TissueNext, the Company's first tissue-based test which will be used to identify patients with advanced cancer who may benefit from biomarker-informed treatment, and Guardant360 Response which will be used to measure early indications to patients' response to treatment up to eight weeks earlier than response evaluation criteria in solid tumors. Using data collected from the Company's tests, the Company has also developed the GuardantINFORM platform to further accelerate precision oncology drug development by biopharmaceutical companies by offering them an in-silico research platform to further unlock insights into tumor evolution and treatment resistance across various biomarker-driven cancers. The Company was incorporated in Delaware in December 2011 and is headquartered in Redwood City, California. In May 2018, the Company formed and capitalized Guardant Health AMEA, Inc., or the Joint Venture, in the United States with an affiliate of SoftBank Vision Fund (AIV M1) L.P., or SoftBank. Under the terms of the joint venture agreement, the Company holds a 50% ownership interest in the Joint Venture. In November 2021, the Company exercised its call right contained in the Joint Venture agreement with SoftBank to purchase all of the shares held by SoftBank and its affiliates, see Note 3. As of December 31, 2021, the Joint Venture has subsidiaries in Singapore and Japan (see Note 3, Investment in Joint Venture ) and the Company has a subsidiary in Switzerland, which was incorporated in 2019.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP. The accompanying consolidated financial statements include the accounts of Guardant Health, Inc., its consolidated Joint Venture and majority owned subsidiary. Other stockholders’ interests in the Joint Venture are shown in the consolidated financial statements as redeemable noncontrolling interest. All significant intercompany balances and transactions have been eliminated in consolidation. The Company believes that its existing cash and cash equivalents and marketable securities as of December 31, 2021 will be sufficient to allow the Company to fund its current operating plan through at least a period of one year after the date the accompanying consolidated financial statements are issued. As the Company continues to incur losses, its transition to profitability is dependent upon a level of revenues adequate to support the Company’s cost structure. If the Company’s transition to profitability is not consistent with its current operating plan, the Company may have to seek additional capital. Use of Estimates The preparation of consolidated 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 consolidated financial statements, as well as the reported amounts of revenues and expenses during the periods presented. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Estimates are used in several areas including, but not limited to, estimation of variable consideration, estimation of credit losses, standalone selling price allocation included in contracts with multiple performance obligations, goodwill and identifiable intangible assets, stock-based compensation, incremental borrowing rate for operating leases, contingencies, certain inputs into the provision for (benefit from) income taxes, including related reserves, valuation of non-marketable securities, valuation of redeemable noncontrolling interest, among others. These estimates generally involve complex issues and require judgments, involve the analysis of historical results and prediction of future trends, can require extended periods of time to resolve and are subject to change from period to period. Actual results may differ materially from management’s estimates. The extent to which the coronavirus 2019, or COVID-19 pandemic, will ultimately impact the Company’s business, results of operations, financial conditions, or cash flows continues to be highly uncertain. The severity of the impact on the Company's business will depend on a number of factors, including, but not limited to, the duration and severity of the pandemic, and the impact of any variants of the virus, the extent and severity of the impact on the Company's customers and suppliers, the continued disruption to demand for the Company's products and services, and the impact of the global business and economic environment on liquidity and the availability of capital, all of which are uncertain and cannot be predicted. Foreign Currency The functional currency of the subsidiaries of the consolidated Joint Venture is the local currency. The assets and liabilities of the subsidiaries are translated into U.S. dollars at exchange rates in effect at each balance sheet date, with the resulting translation adjustments recorded to a separate component of accumulated other comprehensive loss within stockholders’ equity. Income and expense accounts are translated at average exchange rates during the period. Foreign currency transaction gains and losses resulting from transactions denominated in a currency other than the functional currency are recognized in the consolidated statements of operations. For the year ended December 31, 2021, 2020 and 2019, foreign currency transaction gains and losses were immaterial. Segment Information The Company operates as one operating and reportable segment. The Company's chief operating decision makers are its Co-Chief Executive Officers, who review financial information presented on a consolidated basis for the purposes of making operating decisions, assessing financial performance and allocating resources. Cash and Cash Equivalents and Restricted Cash Cash equivalents consist of highly liquid investments with original maturities at the time of purchase of three months or less. Cash equivalents include bank demand deposits and money market accounts that invest primarily in U.S. government-backed securities and treasuries. Cash equivalents are carried at cost, which approximates their fair value. Restricted cash consists of payroll withholding related to the Company's enrollment in certain voluntary disability insurance plan. Restricted cash balance as of December 31, 2021, was $0.1 million, which was included in other assets in the accompanying consolidated balance sheets. The Company did not have any restricted cash as of December 31, 2020. Marketable Securities Marketable securities consist primarily of high-grade U.S. government and agency securities and corporate bonds. Marketable securities with original maturities at the time of purchase between three and twelve months from balance sheet dates are classified as short-term marketable securities and those with maturities over twelve months from balance sheet dates are classified as long-term marketable securities. The Company classifies all marketable securities as available-for-sale, which are recorded at fair value. Unrealized gains and losses are included in accumulated other comprehensive gain (loss) in stockholders’ equity. Any premium or discount arising at purchase is amortized or accreted to interest income or expense. The Company periodically evaluates its available-for-sale marketable securities for impairment. Prior to the adoption of Accounting Standards Update, or ASU, 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments , the Company assesses whether declines in fair values of its marketable securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the marketable security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not that it will be required to sell any marketable securities before recovery of its amortized cost basis. Factors considered include quoted market prices, recent financial results and operating trends, implied values from any recent transactions or offers of investee securities, credit quality of debt instrument issuers, other publicly available information that may affect the value of the marketable security, duration and severity of the decline in value, and management’s strategy and intentions for holding the marketable security. Realized gains and losses and declines in value, if any, judged to be other than temporary on available‑for‑sale securities are reported in other income (expense), net on the consolidated statements of operations. When securities are sold, any associated unrealized gain or loss initially recorded as a separate component of stockholders’ equity is reclassified out of stockholders’ equity on a specific‑identification basis and recorded in earnings for the period. Starting January 1, 2020, upon adoption of ASU 2016-13, when the fair value of a marketable security is below its amortized cost, the amortized cost is reduced to its fair value if it is more likely than not that the Company is required to sell the impaired security before recovery of its amortized cost basis, or the Company has the intention to sell the security. If neither of these conditions are met, the Company determines whether the impairment is due to credit losses by comparing the present value of the expected cash flows of the security with its amortized cost basis. The amount of impairment recognized is limited to the excess of the amortized cost over the fair value of the security. An allowance for credit losses for the excess of amortized cost over the expected cash flows is recorded in other income (expense), net on the consolidated statements of operations. Impairment losses that are not credit-related are included in accumulated other comprehensive gain (loss) in stockholders’ equity. Non-Marketable Securities The Company acquires certain equity investments in private companies to promote business and strategic objectives. The Company's investments in non-marketable equity securities do not give the Company the ability to control or exercise significant influence over the investee. The Company's non-marketable equity and other related investments totaled $39.4 million as of December 31, 2021, and are included in other assets, net on the accompanying consolidated balance sheets. The Company did not have such non-marketable equity and other related investments as of December 31, 2020. Non-marketable securities are subject to periodic impairment reviews and adjustments for observable price changes from orderly transactions. The Company's evaluation of impairment of such non-marketable securities is based on adverse changes in market conditions and the regulatory or economic environment, qualitative and quantitative analysis of the operating performance of the investee; changes in operating structure or management of the investee; additional funding requirements; and the investee’s ability to remain in business. Pursuant to one of the investments in non-marketable securities purchased by the Company, and subject to the Company purchasing additional non-marketable securities from the same investee, the Company would acquire rights to purchase the investee at a pre-determined price subject to additional adjustments based on the performance of the investee, on or before December 31, 2022. As of December 31, 2021, no impairment or adjustments to carrying value of non-marketable securities have been recorded. The Company’s assessment of these factors in determining whether an impairment exists could change in the future due to new developments or changes in applied assumptions. Concentration of Risk The Company is subject to credit risk from its portfolio of cash equivalents held at one commercial bank and investments in marketable securities. The Company limits its exposure to credit losses by investing in money market funds through a U.S. bank with high credit ratings. The Company’s cash may consist of deposits held with banks that may at times exceed federally insured limits, however, its exposure to credit risk in the event of default by the financial institution is limited to the extent of amounts recorded on the consolidated balance sheets. The Company performs evaluations of the relative credit standing of these financial institutions to limit the amount of credit exposure. The Company also invests in investment‑grade debt instruments and has policy limits for the amount it can invest in any one type of security, except for securities issued or guaranteed by the U.S. government. The goals of the Company’s investment policy, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements; and a competitive after‑tax rate of return. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, investment type and issuer, as a result, the Company is not exposed to any significant concentrations of credit risk from these financial instruments. The Company is subject to credit risk from its accounts receivable. The majority of the Company’s accounts receivable arises from the provision of precision oncology services and development services and other in the United States and are primarily with biopharmaceutical companies with high credit ratings. The Company has not experienced any material losses related to receivables from individual customers, or groups of customers. The Company does not require collateral. Accounts receivable are recorded at net amount. A significant customer is a biopharmaceutical customer or a clinical testing payer that represents 10% or more of the Company’s total revenue or accounts receivable balance. Revenue attributable to each significant customer, including its affiliated entities, as a percentage of the Company’s total revenue, for the respective period, and accounts receivable balance attributable to each significant customers, including its affiliated entities, as a percentage of the Company’s total accounts receivable balance, at the respective consolidated balance sheet date, are as follows: Revenue Accounts Receivable, Net Year Ended December 31, As of December 31, 2021 2020 2019 2021 2020 Customer A * 10 % 26 % * 11 % Customer B 29 % 25 % 14 % 13 % 13 % Customer C * * * 10 % 12 % Customer D * * * * 11 % Customer E * * * 13 % * * less than 10% The Company is also subject to credit risk from its other receivables and other assets. The Company's other receivables and other assets include payments due from a third-party in relation to the settlement of a patent dispute reached in August 2020 for $8.0 million payable over a period of 6 years. In December 2020, the Company received the first installment payment of $1.0 million, and in December 2021, the Company received the second installment payment of $1.1 million. The Company has evaluated and recorded a credit loss for the remaining $5.9 million considering the third-party's credit worthiness and lack of financial history. The following table presents the receivable and the related credit loss amounts: Gross Amount Allowance for Credit Losses Net Amount December 31, 2021 December 31, 2020 Year Ended December 31, 2021 December 31, 2021 December 31, 2020 Beginning Balance Charged to (Reversed from) Other Income (Expense), Net Reclassi Ending Balance (in thousand) Prepaid expenses and other current assets $ — $ — $ — $ 1,100 $ (1,100) $ — $ — $ — Other assets 5,900 7,000 (7,000) — 1,100 (5,900) — — Accounts Receivable, Net Accounts receivable represent valid claims against commercial and governmental payers, biopharmaceutical companies, research institutes and international distributors, including unbilled receivables, and royalty payments due from third parties for licensing the Company’s technologies. Unbilled receivables include balances due from biopharmaceutical customers related to development services and other revenues that are recognized upon the achievement of performance-based milestones but prior to the achievement of contractual billing rights. As of December 31, 2021 and 2020, the Company had unbilled receivables of $5.7 million and $1.4 million, respectively. The Company evaluates the collectability of its accounts receivable based on historical collection trends, the financial condition of payment partners, and external market factors and provides for an allowance for potential credit losses based on management’s best estimate of the amount of probable credit losses. As of December 31, 2021 and 2020, the Company had immaterial allowance for credit losses related to its accounts receivable. Inventory Inventories are stated at the lower of cost or net realizable value on a first-in, first-out basis. Inventory consisted entirely of supplies, which are consumed when providing tests, and therefore the Company does not maintain any finished goods inventory. In order to assess the ultimate realization of inventories, the Company is required to make judgments as to future demand requirements compared to current or committed inventory levels. The Company periodically reviews its inventories for excess or obsolescence and writes-down obsolete or otherwise unmarketable inventory to its estimated net realizable value. If the actual net realizable value is less than that estimated by the Company, or if it is determined that inventory utilization will further diminish based on estimates of demand, additional inventory write-downs may be required. Amounts written-down due to unmarketable inventory are recorded in cost of precision oncology testing and cost of development services and other, as appropriate. Property and Equipment, Net Property and equipment are recorded at cost. Depreciation is computed over estimated useful lives of the related assets using the straight-line method. Leasehold improvements are amortized using the straight-line method over the estimated useful lives of the assets or the remaining term of the lease, whichever is shorter. The Company periodically reviews the depreciable lives assigned to property and equipment placed in service and changes the estimates of useful lives, if necessary. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed as incurred. Estimated useful lives for property and equipment are as follows: Property and Equipment Estimated Useful Life Machinery and equipment 3 – 5 years Furniture and fixtures 7 years Computer hardware and computer software 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term Asset Acquisition If an acquisition of an asset or group of assets does not meet the definition of a business, the transaction is accounted for as an asset acquisition rather than a business combination. An asset acquisition does not result in the recognition of goodwill and transaction costs are capitalized as part of the cost of the asset or group of assets acquired. Transaction costs allocated to in-process research and development technology with no future alternate use is expensed as incurred. The total consideration is allocated to the various intangible assets acquired on a relative fair value basis. Cash paid in connection of purchase of in-process research and development technology in an asset acquisition is presented within the investing section of the consolidated statement of cash flows. Goodwill and Intangible Assets, net Intangible assets related to in-process research and development costs, or IPR&D, acquired in a business combination are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts. If and when development is complete, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. Prior to completion of the research and development efforts, the assets are considered indefinite-lived. During this period, the assets will not be amortized but will be tested for impairment on an annual basis and between annual tests if we become aware of any events occurring or changes in circumstances that would indicate a reduction in the fair value of the IPR&D projects below their respective carrying amounts. Goodwill represents the excess of the purchase price over the fair value of net identifiable assets and liabilities. Goodwill and IPR&D are not amortized but are tested for impairment at least annually during the fourth fiscal quarter, or if circumstances indicate their value may no longer be recoverable. The Company continues to operate in one segment, which is considered to be the sole reporting unit and, therefore, goodwill was tested for impairment at the enterprise level. As of December 31, 2021, there has been no impairment of goodwill or IPR&D. Intangible assets are carried at cost, net of accumulated amortization. The Company does not have intangible assets with indefinite useful lives other than goodwill and the acquired IPR&D. Amortization is recorded on a straight-line basis over the intangible asset's useful life, which is approximately 6—12 years. Impairment for Long-Lived Assets The Company evaluates long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the asset may not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than its carrying amount. Impairment, if any, is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value. Leases The Company determines if an arrangement contains a lease at inception. Operating lease right-of-use, or ROU, assets and operating leases liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. ROU assets also include any initial direct costs incurred and any lease payments made at or before the lease commencement date, less lease incentives received or receivable. The Company uses its incremental borrowing rate based on the information available at the commencement date in determining the lease liabilities, as the Company's leases generally do not provide an implicit rate. Lease terms may include options to extend or terminate when the Company is reasonably certain the option will be exercised. Lease expense is recognized on a straight-line basis over the lease term. The Company also has lease arrangements with lease and non-lease components. The Company elected the practical expedient not to separate non-lease components from lease components for the Company’s facility leases. The Company also elected to apply the short-term lease measurement and recognition exemption in which ROU assets and lease liabilities are not recognized for leases with terms of 12 months or less. Convertible Senior Notes In accounting for the issuance of the convertible senior notes, the Company separates the notes into liability and equity components. The carrying amount of the liability component is calculated by measuring the fair value of a similar liability that does not have an associated convertible feature, using a discounted cash flow model with a risk adjusted yield. The carrying amount of the equity component representing the conversion option is determined by deducting the fair value of the liability component from the par value of the notes as a whole. This difference represents a debt discount that is amortized to interest expense using the effective interest method over the term of the notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the transaction costs related to the issuance of the notes, the Company allocated the total amount incurred to the liability and equity components based on their relative fair values. Transaction costs attributable to the liability component are netted with the liability component and amortized to interest expense using the effective interest method over the term of the notes. Transaction costs attributable to the equity component are netted with the equity component of the notes in additional paid-in capital in the consolidated balance sheets. Starting January 1, 2021, upon early adoption of ASU 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, the carrying amount of the equity component of the cash conversion feature including the allocated debt issuance costs were reclassified from additional paid-in capital to convertible senior notes, net. Revenue Recognition The Company derives revenue from the provision of precision oncology testing services provided to its ordering physicians and biopharmaceutical customers, as well as from biopharmaceutical research and development services provided to its biopharmaceutical customers. Precision oncology testing services include genomic profiling and the delivery of other genomic information derived from the Company’s platform. Development services and other include companion diagnostic development, clinical study setup, monitoring and maintenance, information solutions and laboratory services, and other miscellaneous revenue streams. The Company currently receives payments from third-party commercial and governmental payers, certain hospitals and oncology centers and individual patients, as well as biopharmaceutical companies, research institutes and international distributors. Effective January 1, 2019, the Company adopted the new revenue recognition standard, FASB ASC Topic 606, Revenue from Contracts with Customers, or ASC 606 . Revenues are recognized when control of services is transferred to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. ASC 606 provides for a five-step model that includes identifying the contract with a customer, identifying the performance obligations in the contract, determining the transaction price, allocating the transaction price to the performance obligations, and recognizing revenue when, or as, an entity satisfies a performance obligation. Precision oncology testing The Company recognizes revenue from the sale of its precision oncology tests for clinical customers, including certain hospitals, cancer centers, other institutions and patients, at the time results of the test are reported to physicians. Most precision oncology tests requested by clinical customers are sold without a written agreement; however, the Company determines an implied contract exists with its clinical customers. The Company identifies each sale of its test to clinical customer as a single performance obligation. With the exception of certain limited contracted arrangements with insurance carriers and other institutions where the transaction price is fixed, a stated contract price does not exist and the transaction price for each implied contract with clinical customers represents variable consideration. The Company estimates the variable consideration under the portfolio approach and considers the historical reimbursement data from third-party commercial and governmental payers and patients, as well as known or anticipated reimbursement trends not reflected in the historical data. The Company monitors the estimated amount to be collected in the portfolio at each reporting period based on actual cash collections in order to assess whether a revision to the estimate is required. Both the estimate and any subsequent revision contain uncertainty and require the use of significant judgment in the estimation of the variable consideration and application of the constraint for such variable consideration. The Company analyzes its actual cash collections over the expected reimbursement period and compares it with the estimated variable consideration for each portfolio and any difference is recognized as an adjustment to estimated revenue after the expected reimbursement period, subject to assessment of the risk of future revenue reversal. For the year ended December 31, 2021, 2020 and 2019, the Company recorded $19.3 million, $26.0 million and $16.8 million as revenue, respectively, resulting from cash collections exceeding the estimated variable consideration related to samples processed in previous years, including revenue received from successful appeals of reimbursement denials, net of recoupments. Revenue from sales of precision oncology tests to biopharmaceutical customers are based on a negotiated price per test or on the basis of an agreement to provide certain testing volume over a defined period. The Company identifies its promise to transfer a series of distinct tests to biopharmaceutical customers as a single performance obligation. Precision oncology tests to biopharmaceutical customers are generally billed at a fixed price for each test performed. For agreements involving testing volume to be satisfied over a defined period, revenue is recognized over time based on the number of tests performed as the performance obligation is satisfied over time. Results of the Company’s precision oncology services are delivered electronically, and as such there are no shipping or handling fees incurred by the Company or billed to customers. Development services and other The Company performs development services for its biopharmaceutical customers utilizing its precision oncology information platform. Development services typically represent a single performance obligation as the Company performs a significant integration service, such as analytical validation and regulatory submissions. The individual promises are not separately identifiable from other promises in the contracts and, therefore, are not distinct. However, under certain contracts, a biopharmaceutical customer may engage the Company for multiple distinct development services which are both capable of being distinct and separately identifiable from other promises in the contracts and, therefore, distinct performance obligations. The Company collaborates with pharmaceutical companies in the development of new drugs. As part of these collaborations, the Company provides services related to regulatory filings to support companion diagnostic device submissions for the Company’s testing panels. Under these collaborations, the Company generates revenue from achievement of milestones, as well as provision of on-going support. For development services performed, the Company is compensated through a combination of an upfront fee and performance-based, non-refundable regulatory and other developmental milestone payments. The transaction price of the Company's development services contracts typically represents variable consideration. Application of the constraint for variable consideration to milestone payments is an area that requires significant judgment. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be managed to achieve the respective milestone and the level of effort and investment required to achieve the respective milestone. In making this assessment, the Company considers its historical experience with similar milestones, the degree of complexity and uncertainty associated with each milestone, and whether achievement of the milestone is dependent on parties other than the Company. The constraint for variable consideration is applied such that it is probable a significant reversal of revenue will not occur when the uncertainty associated with the contingency is resolved. Application of the constraint for variable consideration is assessed and updated at each reporting period as a revision to the estimated transaction price. The Company recognizes development services revenue over the period in which biopharmaceutical research and development services are provided. Specifically, the Company recognizes revenue using an input method to measure progress, utilizing costs incurred to-date relative to total expected costs as its measure of progress. The Company assesses the changes to the total expected cost estimates as well as any incremental fees negotiated resulting from changes to the scope of the original contract in determining the revenue recognition at each reporting period. For development of new products or services under these arrangements, costs incurred before technological feasibility is reached are included as research and development expenses in the Company’s consolidated statements of operations, while costs incurred thereafter are recorded as cost of development services and other. The Company also has other miscellaneous revenue streams that are recognized in addition to development services noted above such as clinical study setup, monitoring and maintenance, testing development and support, GuardantConnect, GuardantINFORM, and kits fulfillment related revenues. In addition, the Company derives sales- based royalty revenues from licensing its technologies. Revenues related to clinical study setup, monitoring and maintenance, testing development and support, GuardantConnect, GuardantINFORM are generally recognized over time based on an input method to measure progress in the period when the associated services have been performed. Kits fulfillment related revenues are recognized when such products are delivered. Royalty revenues are recognized when actual sales incur. Contracts with multiple performance obligations Contracts with biopharmaceu

Investment in Joint Venture

Investment in Joint Venture	12 Months Ended
	Dec. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Investment in Joint Venture	Investment in Joint Venture Variable Interest Entity, or VIE In May 2018, the Company and an affiliate of SoftBank formed and capitalized the Joint Venture for the sale, marketing and distribution of the Company’s tests in all areas worldwide, outside of North America, Central America, South America, the United Kingdom, all other member states of the EU as of May 9, 2017, Iceland, Norway, Switzerland and Turkey. The Company expects to rely on the Joint Venture to accelerate commercialization of its products in Asia, the Middle East and Africa. Under the terms of the joint venture agreement, the Company paid $9.0 million for 40,000 shares of common stock, or 50% ownership interest, of the Joint Venture, and the affiliate of SoftBank contributed $41.0 million for 40,000 shares of common stock, or the other 50% ownership interest, of the Joint Venture. Neither party has the obligation to provide additional financial support to the Joint Venture. Each party holds two seats on the board of the Joint Venture and has to cast through its representatives on the board at least one vote for any board resolution of the Joint Venture to pass. The representatives of the Company on the Joint Venture’s board of directors have the right to appoint and remove a chief executive officer and a legal representative for the Joint Venture, in each case, subject to the approval of the full Joint Venture board of directors. The Joint Venture’s board of directors has the right to appoint and remove all other members of the Joint Venture’s senior management reporting to its chief executive officer and to approve the compensation of all foregoing individuals, including the compensation of the chief executive officer and legal representative. In June 2020, an amended and restated certificate of incorporation of the Joint Venture, as approved by the board of directors of the Joint Venture, was filed with the Secretary of State of the State of Delaware. The amended and restated certificate of incorporation, among other things, increased the number of authorized shares of common stock to 89,000,000 shares consisting of 80,000,000 shares of Class A common stock and 9,000,000 shares of Class B (non-voting) common stock; and authorized 80,000,000 shares of Series A preferred stock. Pursuant to the amended and restated certificate of incorporation, each share of common stock held by the Company and the affiliate of SoftBank was reclassified and exchanged for 1,000 shares of Series A preferred stock. As a result, each of the Company and the affiliate of SoftBank held 40,000,000 shares of Series A preferred stock. The holders of Series A preferred stock are entitled to receive dividends at the rate of $0.05 per share if and when declared by the board of directors of the Joint Venture. In June 2020, the board of directors of the Joint Venture authorized the adoption of the Joint Venture’s 2020 Equity Incentive Plan pursuant to which 4,595,555 shares of Class B common stock have been reserved for issuance. As of December 31, 2021 and 2020, 602,408 and no shares of Class B common stock have been issued and outstanding, respectively, and no shares of Class A common stock have been issued and outstanding. As of December 31, 2021 and 2020, 80,000,000 shares of Series A preferred stock have been issued and outstanding. At the inception of the arrangement and at the end of each reporting period, the Company assesses whether the Joint Venture is a VIE, and if so, who is the primary beneficiary of the VIE. As of December 31, 2021, the Company and SoftBank had equal ownership interests and equal voting rights in the Joint Venture, and the Joint Venture’s board consisted of an equal number of directors representing the interest of the Company and SoftBank, respectively. As of December 31, 2021, the Joint Venture’s board had the right to vote on all critical matters that most significantly impact the Joint Venture’s economic performance, except that the Company had the unilateral right to make pricing decisions. As of December 31, 2021, the Company had responsibility for the Joint Venture’s daily operations, while SoftBank served as a financing partner. The Company also entered into various ancillary agreements with the Joint Venture necessary to operate its business. The Joint Venture is deemed to be a VIE, and considering the power and benefits criterion, the Company and SoftBank, collectively as a related party group, has the characteristics of the primary beneficiary of the Joint Venture, as the related party group has the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and has the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. Because the Company is most closely associated with the Joint Venture within the related party group, it has been identified as the VIE’s primary beneficiary. As the primary beneficiary, the Company has consolidated the financial position, results of operations and cash flows of the Joint Venture in its financial statements and all intercompany balances have been eliminated in consolidation. The Company concluded the Joint Venture did not meet the definition of a business upon consolidation as it lacked the processes required to generate outputs. Upon consolidation no liabilities were assumed and other than cash, and any identifiable assets were related to intellectual property rights that the Company transferred to the Joint Venture shortly before it became its primary beneficiary and therefore such transfer was treated as a common control transaction. As of December 31, 2021 and 2020, the Joint Venture had total assets of approximately $20.4 million and $35.0 million, respectively, which were primarily comprised of cash, property and equipment, right-of-use assets and security deposits. Although the Company consolidates the Joint Venture, the legal structure of the Joint Venture limits the recourse that its creditors will have over the Company’s general credit or assets. Similarly, the assets held in the Joint Venture can be used only to settle obligations of the Joint Venture. As of December 31, 2021 and 2020, the Company has not provided financial or other support to the Joint Venture that was not previously contracted or required. Put-call arrangements The joint venture agreement includes a put-call arrangement with respect to the shares of the Joint Venture held by SoftBank and its affiliates. Under certain specified circumstances and on terms specified in the joint venture agreement, including timely written notice, SoftBank has the right to cause the Company to purchase all shares of the Joint Venture held by SoftBank and its affiliates, or the put right, and the Company has a right to purchase all such shares, or the call right. If the Company’s business model were to change such that the sale, marketing and distribution of its tests in the territory covered by the joint venture agreement was no longer economical, SoftBank would have the right to cause the Company to purchase, or the Company would have the right to purchase, all of the shares of the Joint Venture held by SoftBank and its affiliates. In this instance, the Company would be required to repurchase the shares at an aggregate purchase price of $41.0 million, the original purchase price paid by SoftBank to the Joint Venture for the shares. Additionally, each of the Company and SoftBank may exercise its respective put-call rights for the Company to purchase all shares of the Joint Venture held by SoftBank in the event of (i) certain material disagreements relating to the Joint Venture or its business that may seriously affect the ability of the Joint Venture to perform its obligations under the joint venture agreement or may otherwise seriously impair the ability of the Joint Venture to conduct its business in an effective matter, other than one relating to the Joint Venture’s business plan or to factual matters that may be capable of expert determination; (ii) the effectiveness of the Company’s initial public offering, a change in control of the Company, the seventh anniversary of the formation of the Joint Venture, or each subsequent anniversary of each of the foregoing events; or (iii) a material breach of the joint venture agreement by the other party that goes unremedied within 20 business days. Unless the shares of the Joint Venture are publicly traded and listed on a nationally recognized stock exchange, the purchase price per share of the Joint Venture in these situations will be determined by a third-party valuation firm on the assumption that the sale is on an arm’s-length basis on the date of the put or call notice. The third-party valuation firm may evaluate a range of factors and employ assumptions that are subjective in nature, which could result in the fair value of SoftBank’s interests in the Joint Venture being determined to be materially different from what has been recorded in the Company’s consolidated financial statements including those included elsewhere in this Annual Report on Form 10-K. The Company may pay the purchase price for the shares of the Joint Venture in cash, in shares of its capital stock (which may be a non-voting security with senior preferences to all other classes of its equity or, if its common stock is publicly traded on a national exchange, its common stock), or in a combination thereof. The noncontrolling interest held by SoftBank contains embedded put-call redemption features that are not solely within the Company’s control and has been classified outside of permanent equity in the consolidated balance sheets. The put-call feature embedded in the redeemable noncontrolling interest do not currently require bifurcation as it does not meet the definition of a derivative and is considered to be clearly and closely related to the redeemable noncontrolling interest. With the Company's exercising the call right, SoftBank no longer has the option to exercise its put right. The Company elected to recognize the changes in redemption value immediately as they occur as if the put-call redemption feature were exercisable at the end of the reporting period. The carrying value of the redeemable noncontrolling interest is first adjusted for the earnings or losses attributable to the redeemable noncontrolling interest based on the percentage of the economic or ownership interest retained in the consolidated VIE by the noncontrolling parties, and then adjusted to equal to its redemption amount, or the fair value of the noncontrolling interest held by SoftBank, as if the redemption were to occur at the end of the reporting date. In November 2021, the Company exercised its call right contained in the joint venture agreement with SoftBank to purchase all of the shares held by SoftBank and its affiliates in consideration for the payment of the aggregate purchase price to be determined based on an independent third-party valuation. The aggregate purchase price will be no less than an amount that yields a 20% internal rate of return on the $41.0 million of capital invested by SoftBank in May 2018 as stipulated in the joint venture agreement. The Company and SoftBank have initiated a process to determine the independent valuation of the Joint Venture, which includes the appointment of independent appraisers by both SoftBank and the Company. As of December 31, 2021, the minimum aggregate purchase price of $78.0 million has been recorded in current liabilities in the Company’s consolidated balance sheet and future adjustments to the aggregate purchase price, if any, will be recorded in net loss in the Company's consolidated statement of operations. The Company expects to complete this transaction before the end of the second quarter of 2022.

Consolidated Balance Sheet Comp

Consolidated Balance Sheet Components	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Consolidated Balance Sheet Components	Consolidated Balance Sheet Components Property and Equipment, Net Property and equipment, net consist of the following: As of December 31, 2021 2020 (in thousands) Machinery and equipment $ 63,022 $ 40,216 Leasehold improvements 38,702 34,037 Computer hardware 16,685 10,862 Construction in progress (1) 55,873 7,833 Furniture and fixtures 3,683 3,043 Computer software 1,320 1,136 Property and equipment, gross $ 179,285 $ 97,127 Less: accumulated depreciation (54,824) (34,345) Property and equipment, net $ 124,461 $ 62,782 (1) Under construction in progress, $45.8 million and $1.1 million was related to leasehold improvements, furniture and equipment for the office in Palo Alto, California, as of December 31, 2021 and 2020, respectively. Depreciation expense related to property and equipment was $20.2 million, $14.1 million and $9.3 million for the years ended December 31, 2021, 2020 and 2019, respectively. Accrued Expenses Accrued expenses consist of the following: As of December 31, 2021 2020 (in thousands) Operating lease liabilities $ 12,856 $ 6,632 Accrued tax liabilities 4,223 4,634 Accrued professional services 6,994 3,397 Accrued clinical studies 3,332 1,264 Accrued legal expenses 4,166 2,875 Purchases of property and equipment included in accrued expenses 5,893 1,156 Others 7,821 2,681 Total accrued expenses $ 45,285 $ 22,639

Fair Value Measurements. Cash E

Fair Value Measurements. Cash Equivalents and Marketable Securities	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements. Cash Equivalents and Marketable Securities	Fair Value Measurements, Cash Equivalents and Marketable Securities Financial instruments consist of cash equivalents, marketable securities, accounts receivable, net, prepaid expenses and other current assets, net, accounts payable and accrued expenses. Cash equivalents and marketable securities are stated at fair value. Prepaid expenses and other current assets, net, accounts payable and accrued expenses are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment date. Fair value is defined as the exchange price that would be received from sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The identification of market participant assumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. A fair value hierarchy has been established which gives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputs into three broad levels as follows: Level 1 - Quoted prices in active markets for identical assets or liabilities. Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company’s financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows: December 31, 2021 Fair Value Level 1 Level 2 Level 3 (in thousands) Financial Assets: Money market funds $ 357,785 $ 357,785 $ — $ — Total cash equivalents $ 357,785 $ 357,785 $ — $ — U.S. government debt securities $ 440,546 $ — $ 440,546 $ — Total short-term marketable securities $ 440,546 $ — $ 440,546 $ — U.S. government debt securities $ 698,034 $ — $ 698,034 $ — Total long-term marketable securities $ 698,034 $ — $ 698,034 $ — Total $ 1,496,365 $ 357,785 $ 1,138,580 $ — Financial Liabilities: Contingent consideration $ 3,625 $ — $ — $ 3,625 Total $ 3,625 $ — $ — $ 3,625 December 31, 2020 Fair Value Level 1 Level 2 Level 3 (in thousands) Financial Assets: Money market funds $ 620,630 $ 620,630 $ — $ — Total cash equivalents $ 620,630 $ 620,630 $ — $ — U.S. government debt securities 961,902 — 961,902 — Total short-term marketable securities $ 961,902 $ — $ 961,902 $ — U.S. government debt securities $ 246,597 $ — $ 246,597 $ — Total long-term marketable securities $ 246,597 $ — $ 246,597 $ — Total $ 1,829,129 $ 620,630 $ 1,208,499 $ — Financial Liabilities: Contingent consideration $ 1,245 $ — $ — $ 1,245 Total $ 1,245 $ — $ — $ 1,245 The Company measures the fair value of money market funds based on quoted prices in active markets for identical securities. U.S. government debt securities are valued taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs. There were no transfers between Level 1, Level 2 and Level 3 during the periods presented. Acquisition-related contingent consideration is measured at fair value on a quarterly basis and change in estimated contingent consideration to be paid are included in operating expenses in the consolidated statements of operations. The fair value of acquisition-related contingent consideration is estimated using a multiple-outcome discounted cash flow valuation technique. Contingent consideration is classified within Level 3 of the fair value hierarchy, as it is based on a probability that includes significant unobservable inputs. The significant unobservable inputs include a probability-weighted estimate of achievement of certain commercialization milestones, continued services from certain former employees and consultants, resulting contingent payments, and discount rate to present value the expected payments. A significant change in any of these input factors in isolation could have a material impact to fair value measurement. As of December 31, 2021, and 2020, contingent consideration liability of $3.6 million and $1.2 million, respectively, was recorded within other long-term liabilities on the consolidated balance sheets. The Company considers the fair value of the noncontrolling interest liability as of December 31, 2021, and the redeemable noncontrolling interest as of December 31, 2020, to be a Level 3 measurement. As of December 31, 2021, the fair value of the noncontrolling interest liability was calculated based on an internal rate of return of 20% on the initial amount of $41 million invested by SoftBank in May 2018. As of December 31, 2020, the fair value of the redeemable noncontrolling interest was determined using a combination of the income approach and the market approach, and estimates and assumptions included future revenue growth rates, gross profit margins, EBITDA margins, future capital expenditures, weighted-average costs of capital and future market conditions, among others. The following tables summarize the activities for the Level 3 financial instruments for the years ended December 31, 2021, 2020 and 2019: Contingent Consideration Year Ended December 31, 2021 2020 2019 (in thousands) Fair value — beginning of period $ 1,245 $ 1,365 $ — Initial valuation on the date of acquisition — — 1,065 Increase (decrease) in fair value 2,380 (120) 300 Fair value — end of period $ 3,625 $ 1,245 $ 1,365 Noncontrolling Interest Liability Redeemable Noncontrolling Interest Year Ended December 31, Year Ended December 31, 2021 2021 2020 2019 (in thousands) Fair value — beginning of period $ — $ 57,100 $ 49,600 $ 41,800 Increase in fair value — 27,244 12,934 11,659 Net loss for the period — (6,344) (5,434) (3,859) Reclassification of redeemable noncontrolling interest to noncontrolling interest liability 78,000 (78,000) — — Fair value — end of period $ 78,000 $ — $ 57,100 $ 49,600 The Company considers the fair value of the Convertible Notes as of December 31, 2021 to be a Level 2 measurement. The fair value of the Convertible Notes is primarily affected by the trading price of the Company's common stock and market interest rates. As such, the carrying value of the Convertible Notes does not reflect the market rate. See Note 8, Debt , for additional information related to the fair value of the Convertible Notes. Cash Equivalents and Marketable Securities The following tables summarizes the Company’s cash equivalents and marketable securities’ amortized costs, gross unrealized gains, gross unrealized losses and estimated fair values by significant investment category: December 31, 2021 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Estimated Fair Value (in thousands) Money market fund $ 357,785 $ — $ — $ 357,785 U.S. government debt securities 1,142,172 2 (3,594) 1,138,580 Total $ 1,499,957 $ 2 $ (3,594) $ 1,496,365 December 31, 2020 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Estimated Fair Value (in thousands) Money market fund $ 620,630 $ — $ — $ 620,630 U.S. government debt securities 1,206,195 2,339 (35) 1,208,499 Total $ 1,826,825 $ 2,339 $ (35) $ 1,829,129 There have been no material realized gains or losses on marketable securities for the periods presented. None of the Company’s investments in marketable securities has been in an unrealized loss position for more than one year. The Company determined that it did have the ability and intent to hold all marketable securities that have been in a continuous loss position until maturity or recovery and the loss position was temporary due to market volatility, thus there has been no recognition of credit losses in the years ended December 31, 2021, 2020 and 2019, respectively. The maturities of the Company’s long-term marketable securities range from 1.1 to 1.8 years as of December 31, 2021.

Patent License Acquisition

Patent License Acquisition	12 Months Ended
	Dec. 31, 2021
Business Combination and Asset Acquisition [Abstract]
Patent License Acquisition	Patent License Acquisition In January 2017, the Company entered into a license agreement with a biotechnology company, KeyGene N.V., or KeyGene. An arbitration was initiated between the parties in 2018. In March 2020, the Company and KeyGene entered into a settlement and patent license agreement, or the SPLA, to resolve the dispute and to acquire an extended worldwide non-exclusive license to certain patent rights with respect to KeyGene’s Next Generation Sequencing technologies along with certain covenant rights and research and development technology for a one-time payment of $18.5 million, ending all future royalty obligations to KeyGene. This transaction was accounted for as an asset acquisition as the purchase did not meet the definition of a business. The total consideration, including $0.6 million of certain capitalizable transaction costs, was allocated to various components of the SPLA. The Company allocated $9.4 million to the patent and covenant rights granted under the SPLA, which have useful lives in the range of 6-12 years. The Company allocated $8.5 million to IPR&D technology, which have no alternative future use and was included in research and development expenses for the year ended December 31, 2020. The remaining $1.2 million was allocated to the settlement of the prior dispute between the parties and was included in general and administrative expenses for the year ended December 31, 2020.

Intangible Assets, Net and Good

Intangible Assets, Net and Goodwill	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net and Goodwill	Intangible Assets, Net and Goodwill The following table presents details of purchased intangible assets as of December 31, 2021 and 2020: December 31, 2021 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Remaining Weighted-Average Useful Life (in thousands) (in years) Intangible assets subject to amortization: Acquired license $ 11,886 $ (2,473) $ 9,413 8.8 Non-compete agreements and other covenant rights 5,100 (1,906) 3,194 3.9 Total intangible assets subject to amortization 16,986 (4,379) 12,607 Intangible assets not subject to amortization: IPR&D 1,600 — 1,600 Goodwill 3,290 — 3,290 Total purchased intangible assets $ 21,876 $ (4,379) $ 17,497 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Remaining Weighted-Average Useful Life (in thousands) (in years) Intangible assets subject to amortization: Acquired license $ 11,886 $ (1,367) $ 10,519 9.8 Non-compete agreements and other covenant rights 5,100 (1,064) 4,036 4.9 Total intangible assets subject to amortization 16,986 (2,431) 14,555 Intangible assets not subject to amortization: IPR&D 1,600 — 1,600 Goodwill 3,290 — 3,290 Total purchased intangible assets $ 21,876 $ (2,431) $ 19,445 Amortization of finite-lived intangible assets was $1.9 million, $1.8 million and $0.7 million, for the years ended December 31, 2021, 2020 and 2019, respectively. The following table summarizes estimated future amortization expense of finite-lived intangible assets, net: Year Ending December 31, (in thousands) 2022 1,947 2023 1,947 2024 1,953 2025 1,670 2026 1,212 2027 and thereafter 3,878 Total $ 12,607

Debt

Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt	Debt Convertible Senior Notes In November 2020, the Company issued $1.15 billion principal amount of its 0% Convertible Senior Notes due 2027, or the 2027 Notes. The 2027 Notes do not bear interest, and the principal amount of the Notes will not accrete. However, special interest and additional interest may accrue on the 2027 Notes at a rate per annum not exceeding 0.50% (subject to certain exceptions) upon the occurrence of certain events such as the failure to file certain reports to the Securities and Exchange Commission, or to remove certain restrictive legends from the Notes. The Notes will mature on November 15, 2027, unless repurchased, redeemed or converted earlier. Before August 15, 2027, holders of the 2027 Notes will have the right to convert their 2027 Notes only under the following circumstances: • during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on March 31, 2021, if the last reported sale price of the Company's common stock exceeds 130% of the conversion price for each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter, or the sale price condition; • during the five consecutive business days immediately after any ten consecutive trading day period, or the measurement period, if the trading price per $1,000 principal amount of the Notes for each trading day of the measurement period is less than 98% of the product of the last reported sale price of the Company's common stock on such trading day and the conversion rate on such trading day; or • upon the occurrence of specified corporate events From and after August 15, 2027, holders of the 2027 Notes may convert their 2027 Notes at any time at their election until the close of business on the second scheduled trading day immediately before the maturity date. The Company will settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election. The initial conversion rate is 7.1523 shares of common stock per $1,000 principal amount of 2027 Notes, which represents an initial conversion price of approximately $139.82 per share of common stock. The conversion rate and conversion price will be subject to customary adjustments upon the occurrence of certain events. In addition, if certain corporate events that constitute a “Make-Whole Fundamental Change” occur, then the conversion rate will, in certain circumstances, be increased for a specified period of time. The Company may not redeem the 2027 Notes at its option at any time before November 20, 2024. The Notes will be redeemable, in whole or in part, at the Company’s option at any time, and from time to time, on or after November 20, 2024 and on or before the 25th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the Notes to be redeemed, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the redemption date, but only if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice; and (ii) the trading day immediately before the date the Company sends such notice. In addition, calling any Note for redemption will constitute a Make-Whole Fundamental Change with respect to that Note, in which case the conversion rate applicable to the conversion of that Note will be increased in certain circumstances if it is converted after it is called for redemption. If certain corporate events that constitute a “Fundamental Change” occur, then, subject to a limited exception for certain cash mergers, holders of Notes may require the Company to repurchase their 2027 Notes at a cash repurchase price equal to the principal amount of the 2027 Notes to be repurchased, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the fundamental change repurchase date. The definition of Fundamental Change includes certain business combination transactions involving the Company and certain de-listing events with respect to the Company’s common stock. In accounting for the 2027 Notes, the Company separated the 2027 Notes into liability and equity components. The carrying amount of the liability component was calculated using a Black-Scholes model by measuring the fair value of a similar instrument 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 2027 Notes as a whole. This difference represents a debt discount that is amortized as interest expense using an effective interest over the term of the 2027 Notes. Effective January 1, 2021, the Company early adopted ASU 2020-06 which resulted in the re-classification of the equity component representing the associated convertible feature and the related debt issuance costs into long-term liabilities with a corresponding impact to retained earnings. Since the 2027 Notes were not convertible as of December 31, 2021, the net carrying amount of the 2027 Notes was classified as a long-term liability. The following table sets forth the components of the 2027 Notes as of December 31, 2021 and 2020: As of December 31, 2021 2020 (in thousands) Liability component: Principal $ 1,150,000 $ 1,150,000 Less: debt discount, net of amortization — (331,074) Less: debt issuance costs, net of amortization (15,179) (12,634) Net carrying amount $ 1,134,821 $ 806,292 Equity component recorded at issuance: 2027 Notes $ — $ 335,667 Less: issuance costs — (5,264) Net amount recorded in equity $ — $ 330,403 The total estimated fair value of the 2027 Notes was $1.2 billion and $1.3 billion as of December 31, 2021 and 2020, respectively. The fair value was determined based on the closing trading price per $100 of the 2027 Notes as of the last day of trading for the period. We consider the fair value of the Notes as of December 31, 2021 to be a Level 2 measurement. The fair value of the 2027 Notes is primarily affected by the trading price of the Company's common stock and market interest rates. The following table sets forth interest expense recognized related to the Notes for the year ended December 31, 2021 and 2020: For the Year Ended December 31, 2021 2020 (in thousands) Amortization of debt discount $ — 4,593 Amortization of debt issuance costs 2,564 136 Total interest expense recognized $ 2,564 $ 4,729 Effective interest rate of the liability component 0.2 % 5.2 % Note Hedges To minimize the impact of potential economic dilution upon conversion of the 2027 Notes, the Company entered into convertible note hedge transactions, or the 2027 Note Hedges, with respect to its common stock concurrent with the issuance of the Notes. The 2027 Note Hedges cover, subject to customary adjustments, the number of shares of common stock initially underlying the Notes. The strike price of the 2027 Note Hedges will initially be approximately $182.60 per share, which represents a premium of 75% over the last reported sale price of the Company’s common stock of $104.34 per share on November 16, 2020, and is subject to certain adjustments under the terms of the 2027 Note Hedges. The 2027 Note Hedges will expire upon maturity of the 2027 Notes. The 2027 Note Hedges are separate transactions and are not part of the terms of the 2027 Notes. Holders of the 2027 Notes will not have any rights with respect to the 2027 Note Hedges. The shares receivable related to the 2027 Note Hedges are excluded from the calculation of diluted earnings per share as they are anti-dilutive.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	Leases The Company has entered into various operating lease agreements for office space, data center, lab and warehouse use, with remaining terms ranging from 1 year to 12 years some of which include one or more options to renew. As leases approach maturity, the Company considers various factors such as market conditions and the terms of any renewal options that may exist to determine whether it will renew the lease, as such, the Company does not include renewal options in its lease terms for calculating its lease liability, as the renewal options allow it to maintain operational flexibility and the Company is not reasonably certain it will exercise these renewal options at the time of the lease commencement. In July 2020, the Company entered into two lease agreements for additional office space in Palo Alto, California, the Palo Alto Lease, and in San Diego, California, the San Diego Lease. The San Diego Lease has a term of 8 years with rent payments commencing in May 2022. The Palo Alto Lease has a term of 12 years with an option to renew the lease term for an additional ten years which has not been considered in the determination of ROU or the lease liability as the Company does not consider it reasonably certain of exercising the renewal option. Rent payments for the Palo Alto Lease will commence in June 2022. Both leases consist of fixed and variable payments and are being accounting for as operating leases. The Company took possession of these facilities in March 2021. The Company estimated the incremental borrowing rate to determine the present value of lease payments for the San Diego and Palo Alto leases using trading data of the Company's convertible debt adjusted for credit rating and market yield curves. Operating lease expense for the year ended December 31, 2021, 2020 and 2019, was $24.7 million, $5.6 million and $4.4 million, which includes both lease and non-lease components (primarily common area maintenance charges and property taxes). As of December 31, 2021 2020 Weighted-average remaining lease term (in years) 10.0 5.5 Weighted-average discount rate 4.01 % 8.07 % The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of December 31, 2021: Year Ending December 31, (in thousands) 2022 $ 18,840 2023 29,056 2024 31,584 2025 32,063 2026 27,753 2027 and thereafter 149,637 Total operating lease payments $ 288,933 Less: Imputed Interest (50,024) Total operating lease liabilities $ 238,909 Finance leases are not material to the Company's consolidated financial statements.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies License Agreements The Company has patent license agreements with four different parties. Under these agreements, the Company has made one-time upfront and milestone payments, which it has capitalized and is amortizing to expense ratably over the useful life of the underlying patent right(s). Under some of these agreements, the Company is obligated to pay low single-digit percentage running royalties on net sales where the licensed patent right(s) are used in the product or service sold, subject to minimum annual royalties or fees in certain agreements. Royalty expenses were included in cost of precision oncology testing on the accompanying consolidated statements of operations. The Company recognized royalty expenses of $0.7 million, $1.1 million and $4.4 million, or 0.2%, 0.4% and 2% of precision oncology testing revenue in each period, for the years ended December 31, 2021, 2020 and 2019, respectively. Indemnification Agreements The Company has entered into indemnification agreements with certain directors and officers that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. To date, no such matters have arisen and the Company does not believe that the outcome of any claims under indemnification arrangements will have a material adverse effect on its financial positions, results of operations or cash flows. Accordingly, the Company has not recorded a liability related to such indemnifications as of December 31, 2021. Legal Proceedings In addition to commitments and obligations incurred in the ordinary course of business, from time to time the Company may be subject to a variety of claims and legal proceedings, including claims from customers and vendors, pending and potential legal actions for damages, governmental investigations and other matters. For example, the Company has received, and may in the future continue to receive letters, claims or complaints from others alleging false advertising, patent infringement, violation of employment practices and trademark infringement. The Company has also instituted, and may in the future institute, additional legal proceedings to enforce its rights and seek remedies, such as monetary damages, injunctive relief and declaratory relief. The Company cannot predict the results of any such disputes, and despite the potential outcomes, the existence thereof may have an adverse material impact on the Company because of diversion of management time and attention as well as the financial costs related to resolving such disputes. The Company and its affiliates are parties to the legal claims and proceedings described below. The Company is vigorously defending itself against those claims and in those proceedings. Significant developments in those matters are described below. If the Company is unsuccessful in defending, or if it determines to settle, any of these matters, it may be required to pay substantial sums, be subject to injunction and/or be forced to change how it operates its business, which could have a material adverse impact on its financial position or results of operations. Unless otherwise stated, the Company is unable to reasonably estimate the loss or a range of possible loss for the matters described below. Often, it is not reasonably possible for the Company to determine that a loss is probable for a claim, or to reasonably estimate the amount of loss or a range of loss, because of the limited information available and the potential effects of future events and decisions by third parties, such as courts and regulators, that will determine the ultimate resolution of the claim. Many of the matters described are at preliminary stages, raise novel theories of liability or seek an indeterminate amount of damages. It is not uncommon for claims to be resolved over a number of years. The Company reviews loss contingencies at least quarterly to determine whether the loss probability has changed and whether it can make a reasonable estimate of the possible loss or range of loss. When the Company determines that a loss from a claim is probable and reasonably estimable, it records a liability in the amount of its estimate for the ultimate loss. The Company also provides disclosure when it is reasonably possible that a loss may be incurred or when it is reasonably possible that the amount of a loss will exceed its recorded liability. Patent Disputes In November 2017, the Company filed a lawsuit against Foundation Medicine, Inc., or Foundation Medicine, in the United States District Court for the District of Delaware. The Company has alleged that Foundation Medicine has infringed four of the Company’s digital sequencing technology patents. Foundation Medicine has asserted counterclaims of patent invalidity, unenforceability under the doctrine of inequitable conduct, license and non-infringement. The parties are seeking damages, injunctive relief and attorneys’ fees. Discovery in the lawsuit has closed, and a number of pre-trial motions were filed in September and October 2020. Foundation Medicine also filed six petitions for inter partes review with the PTAB, challenging the patentability of all four of the patents asserted by the Company. The PTAB denied institution of inter partes review for four of the six petitions filed by Foundation Medicine and instituted inter partes review for the remaining two petitions. In November 2020, the Company filed a lawsuit against Foundation Medicine in the United States District Court for the District of Delaware, wherein the Company alleged that Foundation Medicine infringes seven of the Company’s patents. Foundation Medicine has asserted counterclaims of patent invalidity, unenforceability under the doctrine of inequitable conduct, license, non-infringement, and that the Company has violated Section 2 of Sherman Act. In December 2020, the Company filed a Motion for a Preliminary Injunction to prohibit Foundation Medicine from practicing two of the asserted patents. In March 2021, the Company filed two lawsuits against Foundation Medicine GmbH in the District Court of Munich I in Germany, wherein the Company alleged that Foundation Medicine GmbH infringes two of the Company’s patents. In May 2021, the Company entered into a binding term sheet, or the Term Sheet, with Foundation Medicine, which upon execution of a definitive settlement agreement, would result in the dismissal of all pending patent litigation between the parties regarding the Company’s digital sequencing technology patents, or collectively, the Patents. Under the Term Sheet, Foundation Medicine will pay the Company $25.0 million as well as certain royalties for the remaining term of the Patents, while the Company will grant Foundation Medicine a non-exclusive license to the Patents. In December 2021, the Company entered into a Settlement and License Agreement with Foundation Medicine, the terms and conditions of which were consistent with the Term Sheet, resulting in the dismissal of all pending patent litigation worldwide between the parties. In August 2020, the Company and Personal Genome Diagnostics, Inc. settled the patent infringement lawsuit brought by the Company. Under the terms of the confidential settlement, the lawsuit and counterclaims, as well as other challenges to the Company’s patents, have been dismissed. In August 2021, TwinStrand Biosciences, Inc., or TwinStrand Biosciences, and the University of Washington filed a patent infringement suit in the United States District Court for the District of Delaware alleging that the Company infringes U.S. Patent Nos. 10,287,631; 10,689,699; 10,752,951; and 10,760,127. The Company answered the complaint in October 2021, denying TwinStrand Biosciences’ allegations and asserted counterclaims of invalidity, unenforceability due to inequitable conduct and infringement of four of the Company’s patents. Discovery in the case is ongoing and trial is scheduled to commence in November 2023. False Advertising Dispute In May 2021, the Company also filed a lawsuit against Natera, Inc., or Natera, in the United States District Court for the Northern District of California, wherein the Company alleged that Natera is misleading healthcare providers about the performance of the Company’s new oncology test, Guardant Reveal, by suggesting the test is inaccurate and/or insensitive, and inferior to Natera’s Signatera assay. The Company is seeking an injunction to prevent Natera from continuing to make false and misleading statements and to require Natera to take corrective actions. Natera has asserted counterclaims of false and misleading statements, false advertising, unlawful trade practices and unfair competition. The Company moved to dismiss Natera’s counterclaims, and in January 2022, the United States District Court for the Northern District of California granted in part and denied in part our motion to dismiss. Discovery is ongoing and trial is scheduled to commence in December 2022. Civil Investigative Demand In January 2022, the Company received a Civil Investigative Demand, or CID, from the United States Attorney for the Northern District of California in connection with an investigation under the False Claims Act. The CID requests information and documents regarding billing of government-funded programs for the Company’s panel of genetic tests known as Guardant360. The Company is fully cooperating with the investigation. At this time, the Company is unable to predict the outcome of this investigation.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Common Stock	Common StockThe Company’s common stockholders are entitled to dividends if and when declared by the Company’s Board of Directors, or the Board of Directors. As of December 31, 2021 and 2020, no dividends on the Company’s common stock had been declared by the Board of Directors. The Company’s common stock has been reserved for the following potential future issuances: As of December 31, 2021 2020 Shares underlying outstanding stock options 2,624,974 3,101,181 Shares underlying unvested restricted stock units 1,498,553 1,118,655 Market-based restricted stock units 2,260,764 3,391,148 Performance-based restricted stock units 374,596 377,922 Shares available for issuance under the 2018 Incentive Award Plan 5,231,624 1,819,223 Shares available for issuance under the 2018 Employee Stock Purchase Plan 1,426,264 1,536,491 Total 13,416,775 11,344,620 Follow-on Offering In May 2019, the Company completed an underwritten public offering, in which it issued and sold 5,175,000 shares of its common stock at a price of $71.00 per share. The Company received net proceeds of $349.7 million after deducting underwriting discounts and commissions and offering expenses payable by the Company. In June 2020, the Company completed an underwritten public offering, in which it issued and sold 4,312,500 shares of its common stock at a price of $84.00 per share. The Company received net proceeds of $354.6 million after deducting underwriting discounts and commissions and offering expenses payable by the Company.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2012 Stock Plan and 2018 Incentive Award Plan In June 2012 and September 2018, the Company’s Board of Directors adopted and its stockholders approved the Company’s 2012 Stock Plan, or as amended and restated, the 2012 Plan, and the Company’s 2018 Incentive Award Plan, or the 2018 Plan, respectively, under which the Company may grant cash and equity incentive awards such as stock options, restricted shares, stock units and stock appreciation rights to its employees and non-employees. Stock options granted may be either incentive stock options or nonstatutory stock options. Shares issued under the 2018 Plan may be authorized but unissued shares, or shares purchased in the open market or treasury shares. Upon effectiveness of the 2018 Plan in connection with the IPO in October 2018, the 2012 Plan was terminated and 508,847 shares reserved under the 2012 Plan were forfeited. Any outstanding awards granted under the 2012 Plan remain outstanding, subject to the terms of the 2012 Plan and applicable award agreement, and further cancellation of awards granted under the 2012 Plan are not available for grant in the future. No further grants will be made under the 2012 Plan. Stock Option Activity A summary of the Company’s stock option activity under the 2012 Plan and the 2018 Plan and related information is as follows: Options Outstanding Shares Shares Subject to Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 1, 2019 3,556,507 7,588,405 $ 4.58 8.3 $ 250,495 Granted (324,579) 324,579 88.18 Exercised — (2,999,419) 3.87 Canceled 12,636 (418,676) 6.64 Restricted stock units granted (567,425) — Restricted stock units canceled 49,086 — Balance as of December 31, 2019 2,726,225 4,494,889 10.90 7.7 306,392 2018 Plan annual increase (1) 3,689,000 — Granted (127,590) 127,590 81.78 Exercised — (1,446,843) 6.59 Canceled 20,370 (74,455) 12.13 Restricted stock units granted (823,454) — Restricted stock units canceled 103,742 — Market-based restricted stock units granted (3,391,148) — Performance-based restricted stock units granted (377,922) — Balance as of December 31, 2020 1,819,223 3,101,181 15.80 6.9 350,670 2018 Plan annual increase (1) 3,689,000 — Granted (345,774) 345,774 119.82 Exercised — (693,074) 11.19 Canceled 65,523 (128,907) 47.51 Restricted stock units granted (873,916) — Restricted stock units canceled 315,988 — Market-based restricted stock units granted — — Market-based restricted stock units canceled 558,254 — Performance-based restricted stock units granted (52,917) — Performance-based restricted stock units canceled 56,243 — Balance as of December 31, 2021 5,231,624 2,624,974 $ 29.17 6.5 $ 193,014 Vested and Exercisable as of December 31, 2021 1,973,789 $ 11.05 5.8 $ 175,783 (1) Effective as of January 1, 2020, an additional 3,689,000 shares of common stock became available for issuance under the 2018 Plan, as a result of the operation of an automatic annual increase provision therein. Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options. The total intrinsic value of the options exercised was $83.5 million, $120.0 million and $218.2 million for the years ended December 31, 2021, 2020 and 2019, respectively. The weighted-average grant date fair value of options granted was $70.25, $48.99 and $52.37 per share for the years ended December 31, 2021, 2020 and 2019, respectively. Future stock-based compensation for unvested options as of December 31, 2021 was $31.7 million, which is expected to be recognized over a weighted-average period of 3.0 years. On December 31, 2020 and 2019, the Company modified one of the performance based awards issued to a nonemployee which resulted in reversal of expense of $0.7 million and $1.0 million, respectively, due to options not vested. There was no such modification in 2021. Restricted Stock Units A summary of the Company’s restricted stock unit activity excluding the performance-based and market-based restricted stock units under the 2012 Plan and the 2018 Plan and related information is as follows: Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of January 1, 2019 — $ — Granted 567,425 78.61 Vested and released (22,208) 47.78 Canceled (49,086) 57.51 Balance as of December 31, 2019 496,131 82.08 Granted 823,454 96.39 Vested and released (97,188) 81.43 Canceled (103,742) 79.72 Balance as of December 31, 2020 1,118,655 92.89 Granted 873,916 123.36 Vested and released (178,030) 92.14 Canceled (315,988) 97.79 Balance as of December 31, 2021 1,498,553 $ 109.72 Future stock-based compensation for unvested restricted stock units as of December 31, 2021 was $142.8 million, which is expected to be recognized over a weighted-average period of 3.1 years. Performance-based Restricted Stock Units Since November 2020, the Compensation Committee of the Board of Directors started to approve, and the Company started to grant performance-based restricted stock units, or PSUs, under the 2018 Plan. The PSUs granted to employees consist of financial and operational metrics to be met over a performance period of 4 years and an additional service period requirement of six months after the performance metrics are met. The PSUs granted to a consultant consistent of operational metrics to be met over a performance period of 4 years. The PSUs are expected to be expensed over a period of approximately 4 years to 4.5 years subject to meeting the respective performance metrics and service requirements. As of December 31, 2021, a significant portion of these PSUs are not expected to achieve the related performance metrics, and therefore, no stock-based compensation expense was recorded for the PSUs that were not probable to vest. A summary of the Company’s performance-based restricted stock unit activity under the 2018 Plan and related information is as follows: Performance-based Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of January 1, 2020 — $ — Granted 377,922 113.40 Balance as of December 31, 2020 377,922 113.40 Granted 52,917 135.94 Canceled (56,243) 113.40 Balance as of December 31, 2021 374,596 $ 116.58 Stock-based compensation recorded for the PSUs for the year ended December 31, 2021 and 2020 was $1.3 million and $0.1 million, respectively. Future stock-based compensation for unvested PSUs that are probable to vest as of December 31, 2021 was $3.9 million, which is expected to be recognized over a weighted-average period of 3.1 years. Market-based Restricted Stock Units In May 2020, the Board of Directors approved and granted 1,695,574 market-based restricted stock units, or MSUs, under the 2018 Plan to each of the Company's Co-Chief Executive Officers, which is subject to the achievement of market-based share price goals established by the Board of Directors. The MSUs consist of three separate tranches and the vesting of each tranche is subject to the Company's common stock closing price being maintained at or above a predetermined share price goal for a period of 30 consecutive calendar days. The share price goal can be met any time during the seven-year performance period from the date of grant. Upon vesting, the MSUs must be held for a period of six Tranche Price Goal Number of RSUs Tranche 1 $120 per share 565,192 Tranche 2 $150 per share 565,191 Tranche 3 $200 per share 565,191 The grant date fair values of the MSUs were determined using a Monte Carlo valuation model for each tranche. The related stock-based compensation expense for each tranche is recognized based on an accelerated attribution method over the estimated derived service period. If the related share price goal is achieved earlier than its expected derived service period, the stock-based compensation expense will be recognized as a cumulative catch-up expense from the grant date to that point in time in achieving the share price goal. The derived service period is the median duration of the successful stock price paths to meet the price goal for each tranche as simulated in the Monte Carlo valuation model. The Monte Carlo valuation model uses assumptions such as volatility, risk-free interest rate, cost of equity and dividend estimated for the performance period of the MSU. The weighted-average grant date fair value of the MSUs was $67.00 and the weighted-average derived service period was estimated to be in the range of 0.83 – 2.07 years. On January 1, 2021, Tranche 1 of the MSUs became vested because it has met both service requirement and market-based performance metrics as the predetermined share price goal of $120 per share was achieved for a period of 30 consecutive calendar days. A summary of the Company’s market-based restricted stock unit activity under the 2018 Plan and related information is as follows: Market-based Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of January 1, 2020 — $ — Granted 3,391,148 67.00 Balance as of December 31, 2020 3,391,148 67.00 Vested and released (572,130) 70.58 Canceled (1) (558,254) 70.58 Balance as of December 31, 2021 2,260,764 $ 65.20 (1) Represented shares withheld by the Company for MSU holders' tax obligation upon release of vested MSUs. Stock-based compensation recorded for the MSUs for the year ended December 31, 2021 and 2020 was $99.2 million and $111.9 million, respectively, and is recorded in general and administrative expenses in our consolidated statement of operations. Future stock-based compensation for unvested MSUs as of December 31, 2021 was $16.1 million, which is expected to be recognized over a weighted-average period of 0.5 years. In the event of a change in control, a qualifying termination, death, disability or the share price goal occurring earlier than the estimated derived service period, the stock-based compensation relating to these MSUs could be accelerated. Any MSUs that remain unvested at the end of the 7-year performance period will automatically be forfeited and terminated without further consideration. AMEA 2020 Equity Incentive Plan In August 2020, the board of directors of the Joint Venture approved its 2020 Equity Incentive Plan, or the AMEA 2020 Plan, under which the Joint Venture may grant equity incentive awards such as stock options, restricted stock, restricted stock units, stock appreciation rights and cash-based awards to its employees and non-employees. Stock options granted may be either incentive stock options or nonstatutory stock options. Incentive stock options may be granted only to employees of the Joint Venture or its affiliates. Nonstatutory stock options may be granted to employees, directors and non-employee consultants. Stock options may be granted at an exercise price of not less than the fair market value of the Joint Venture's common stock on the date of grant, determined by the board of directors of the Joint Venture. Options generally vest over 4 years and expire as determined by the board of directors of the Joint Venture, provided that the term of options may not exceed 10 years from the date of grant. For individuals holding more than 10% of the total combined voting power of all classes of stock of the Joint Venture, the exercise price of an option will not be less than 110% of the fair market value of the Joint Venture's common stock on the date of grant, and the term of the option will not exceed 5 years. A total of 4,595,555 shares of the Joint Venture's Class B common stock are initially reserved for issuance under the AMEA 2020 Plan, and the number of shares may be increased in accordance with the terms of the AMEA 2020 Plan. A summary of the Joint Venture's stock option activity under the AMEA 2020 Plan and related information is as follows: Options Outstanding Shares Shares Subject to Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 1, 2020 — — $ — 0.0 $ — Shares authorized 4,595,555 — — Granted (4,062,224) 4,062,224 0.58 Canceled 8,889 (8,889) — Balance as of December 31, 2020 542,220 4,053,335 0.58 9.6 — Granted (826,667) 826,667 0.58 Exercised — (602,408) 0.58 Canceled 625,375 (625,375) 0.58 Balance as of December 31, 2021 340,928 3,652,219 $ 0.58 8.8 $ — Vested and Exercisable as of December 31, 2021 2,148,474 $ 0.58 8.6 $ — The weighted-average grant date fair value of options granted was $0.33 and $0.33 per share for the years ended December 31, 2021 and 2020, respectively. Future stock-based compensation for unvested options as of December 31, 2021 was $0.4 million, which is expected to be recognized over a weighted-average period of 2.5 years. Stock‑Based Compensation Expense The following table presents the effect of employee and non‑employee related stock‑based compensation expense including the Joint Venture: Year Ended December 31, 2021 2020 2019 (in thousands) Cost of precision oncology testing $ 3,468 $ 1,839 $ 863 Research and development expense 18,907 10,024 5,907 Sales and marketing expense 15,479 9,279 4,716 General and administrative expense 113,595 122,971 5,468 Total stock-based compensation expense $ 151,449 $ 144,113 $ 16,954 Valuation of Stock Options Starting January 1, 2019, the Company adopted ASU 2018-07 which aligns the accounting treatment of nonemployee awards with employee awards, and the fair value of stock options issued to employees and nonemployee consultants are both determined as of the grant date. The grant date fair value of stock options was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions including the Joint Venture: Year Ended December 31, 2021 2020 2019 Expected term (in years) 5.49 – 6.06 5.50 – 6.10 5.50 – 6.22 Expected volatility 63.6% – 66.7% 63.6% – 73.3% 63.2% – 68.7% Risk-free interest rate 0.3% – 1.3% 0.3% – 1.6% 1.6% – 2.7% Expected dividend yield —% —% —% The determination of the fair value of stock options on the date of grant using a Black-Scholes option-pricing model is affected by the estimated fair value of common stock of the Company and the Joint Venture, as well as assumptions regarding a number of variables that are complex, subjective and generally require significant judgment to determine. The valuation assumptions were determined as follows: Fair Value of Common Stock The fair value of the Company’s common stock is determined by the closing price, on the date of grant, of its common stock, which is traded on the Nasdaq Global Select Market. The grant date fair value of the Joint Venture's common stock has been determined by the board of directors of the Joint Venture. The grant date fair value of the Joint Venture’s common stock was determined using valuation methodologies which utilize certain assumptions including probability weighting of events, volatility, time to liquidation, a risk-free interest rate and an assumption for a discount for lack of marketability. In determining the fair value of the Joint Venture’s common stock, the methodologies used to estimate the enterprise value of the Joint Venture were performed using methodologies, approaches, and assumptions consistent with the American Institute of Certified Public Accountants Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation . Expected Term The expected term represents the period that the options granted are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term) as the Company has concluded that its stock option exercise history does not provide a reasonable basis upon which to estimate expected term. Expected Volatility Prior to the commencement of trading of the Company’s common stock on the Nasdaq Global Select Market on October 4, 2018 in connection with the IPO, there was no active trading market for the Company’s common stock. Due to limited historical data for the trading of the Company’s common stock, expected volatility is estimated based on the average volatility for comparable publicly traded peer group companies in the same industry plus the Company's expected volatility for the available periods. The comparable companies are chosen based on their similar size, stage in the life cycle or area of specialty. The Joint Venture derived the expected volatility from the average historical volatility over a period approximately equal to the expected term of comparable publicly traded companies within its peer group that were deemed to be representative of future stock price trends as the Joint Venture does not have any trading history for its common stock. The Joint Venture will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Risk-Free Interest Rate The risk-free interest rate is based on the U.S. Treasury rate, with maturities similar to the expected term of the stock options. Expected Dividend Yield The Company and the Joint Venture does not anticipate paying any dividends in the foreseeable future and, therefore, uses an expected dividend yield of zero. Valuation of MSUs The estimated fair value of the MSUs was determined using a Monte Carlo simulation model. The valuation assumptions used were substantially consistent with the assumption used to value stock options with the exception of the following: Expected Volatility Due to limited historical data for the trading of the Company’s common stock, expected volatility is estimated based on the average volatility for comparable publicly traded peer group companies and implied volatility of publicly traded options in the same industry plus the Company's expected volatility for the available periods. The comparable companies are chosen based on their similar size, stage in the life cycle or area of specialty. Expected Term The expected term represents the derived service period for the respective tranches which has been estimated using the Monte Carlo simulation model. Risky Rate The risky rate represents the Company's cost of equity. Discount for Lack of Marketability The discount for lack of marketability represents the discount applied for post vest term restrictions and has been derived using the Monte Carlo simulation model. The following assumptions were used to calculate the stock-based compensation for MSUs: a weighted-average expected term of 0.83 – 2.07 years; expected volatility of 65.5%; a risk-free interest rate of 0.53%; a zero dividend yield; a risky rate (cost of equity) of 16%; and a discount for post-vesting restrictions of 10.4% – 14.5%. 2018 Employee Stock Purchase Plan In September 2018, the Company’s Board of Directors adopted and its stockholders approved the 2018 Employee Stock Purchase Plan, or the ESPP. A total of 922,250 shares of common stock were initially reserved for issuance under the ESPP. Effective as of January 1, 2020, an additional 942,614 shares of common stock became available for issuance under the ESPP, as a result of the operation of an automatic annual increase provision therein. Subject to any plan limitations, the ESPP allows eligible employees to contribute, normally through payroll deductions, up to 10% of their earnings for the purchase of the Company’s common stock at a discounted price per share. The price at which common stock is purchased under the ESPP is equal to 85% of the fair market value of the Company’s common stock on the first or last day of the offering period, whichever is lower. The initial offering period ran from October 2, 2018 to January 31, 2019, the second offering period ran from February 1, 2019 to July 31, 2019, and the third offering period began on August 1, 2019 and ran to November 14, 2019. For subsequent years, the ESPP provides for separate six-month offering periods beginning on May 15 and November 15 of each year. Shares of common stock purchased under the ESPP were 110,227, 96,040 and 232,333, for the years ended December 31, 2021, 2020 and 2019, respectively. The total compensation expense related to the ESPP was $3.5 million, $3.0 million and $2.3 million for the years ended December 31, 2021, 2020 and 2019, respectively. The fair value of the stock purchase right granted under the ESPP was estimated on the first day of each offering period using the Black-Scholes option pricing model. The valuation assumptions used were substantially consistent with the assumption used to value stock options with the exception of the expected term which was based on the term of each purchase period. The grant date fair value of the stock purchase right granted under the ESPP was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2021 2020 2019 Expected term (in years) 0.50 0.50 0.29 – 0.50 Expected volatility 46.5% – 50.8% 45.7% – 73.2% 58.8% – 60.3% Risk-free interest rate —% – 0.1% 0.1% – 0.2% 1.6% – 2.5% Expected dividend yield —% —% —% As of December 31, 2021, the unrecognized stock-based compensation expense related to the ESPP was $1.6 million , which is expected to be recognized over the remaining term of the offering period of 0.4 years.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders	Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders The following table sets forth the computation of the basic and diluted net loss per share attributable to Guardant Health, Inc. common stockholders: Year Ended December 31, 2021 2020 2019 (in thousands, except per share data) Net loss $ (384,770) $ (246,283) $ (67,851) Adjustment of redeemable noncontrolling interest (20,900) (7,500) (7,800) Net loss attributable to Guardant Health, Inc. common stockholders, basic and diluted $ (405,670) $ (253,783) $ (75,651) Net loss per share attributable to Guardant Health, Inc. common stockholders, basic and diluted $ (4.00) $ (2.60) $ (0.84) Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, basic and diluted 101,314 97,504 90,597 Since the Company was in a loss position for all periods presented, basic net loss per share attributable to Guardant Health, Inc. common stockholders is the same as diluted net loss per share attributable to Guardant Health, Inc. common stockholders, as the inclusion of all potential shares of common stock outstanding would have been anti-dilutive. The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share attributable to Guardant Health, Inc. common stockholders for the periods presented as they had an anti-dilutive effect: Year Ended December 31, 2021 2020 2019 (in thousands) Stock options issued and outstanding (1) 2,715 3,830 5,976 Restricted stock units 1,208 687 252 MSUs 2,357 2,031 — PSUs 397 60 — ESPP obligation 45 37 52 Common stock subject to repurchase 7 18 31 Convertible senior notes 8,225 961 — Total 14,954 7,624 6,311

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of loss before provision for income taxes were as follows (in thousands): Year Ended December 31, 2021 2020 2019 (in thousands) United States $ (384,976) $ (246,463) $ (69,930) Foreign 506 559 207 Total (384,470) (245,904) (69,723) The components of the provision for income taxes are as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Current: State $ 4 $ 5 $ 3 Foreign 118 242 266 Total current tax expense $ 122 $ 247 $ 269 Deferred: Federal $ 108 $ 184 $ (1,652) State 20 34 (311) Foreign 50 (86) (178) Total deferred tax expense $ 178 $ 132 $ (2,141) Total provision for income taxes $ 300 $ 379 $ (1,872) Deferred income taxes reflect the tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets are as follows: As of December 31, 2021 2020 (in thousands) Deferred tax assets: Net operating losses carryforwards $ 232,657 $ 133,015 Property, equipment and intangible assets 13,233 14,198 Accruals and reserves 10,326 10,117 Research and development credits 33,977 19,022 Stock-based compensation 10,217 28,745 Lease liabilities 59,465 12,092 Other 948 65 Total deferred tax asset $ 360,823 $ 217,254 Deferred tax liabilities: Section 481 (a) adjustment (305) (607) Right-of-use asset (47,130) (9,383) Unrealized gain/loss on investments — (571) Debt discount — (81,964) Other (14) — Total deferred tax liabilities (47,449) (92,525) Less: valuation allowance (313,125) (124,433) Net deferred tax assets $ 249 $ 296 The following table presents a reconciliation of the income tax expense computed at the statutory federal rate and the Company’s income tax expense for the periods presented: Year Ended December 31, 2021 2020 2019 (in thousands) Tax at the statutory federal rate $ (80,739) $ (51,639) $ (14,642) Other nondeductible items 1,399 786 887 Stock-based compensation 1,354 (13,382) (33,042) Research and development credits (14,956) (7,890) (5,266) Change in valuation allowance 106,227 81,395 59,049 State taxes, net of federal benefits (14,998) (11,119) (8,253) Other 2,013 2,228 (605) Total provision for (benefit from) income taxes $ 300 $ 379 $ (1,872) The Company’s actual tax expense differed from the statutory federal income tax expense using a tax rate of 21% for the year ended December 31, 2021, 2020 and 2019, primarily due to state and foreign income taxes, nondeductible expenses, research and development tax credits, the acquisition of Bellwether Bio, Inc., or "Bellwether Bio", and the change in valuation allowance. The benefit from income taxes for the year ended December 31, 2019 included a release of a valuation allowance of $1.6 million associated with nondeductible intangible assets recorded as a result of the acquisition of Bellwether Bio. In connection with the acquisition of Bellwether Bio, a deferred tax liability was established for the book-tax basis differences related to the non-goodwill intangible assets. The net deferred tax liability from this acquisition creates an additional source of income to offset the Company’s deferred tax assets. The benefit from income taxes for the year ended December 31, 2019 also included a benefit of $0.4 million associated with the utilization of tax losses from continuing operations against other comprehensive income gains in accordance with intra-period tax allocation under ASC Topic 740. As of December 31, 2021 and 2020, the Company had a net operating loss carryforwards of $956.9 million and $547.3 million for federal purposes, and $542.0 million and $306.7 million for state and local purposes, respectively, which may be subject to limitations as described below. If not utilized, these carryforwards will begin to expire in 2031 for federal, and 2022 for state and local purposes. Federal net operating losses incurred in 2018 and in future years may be carried forward indefinitely, but the deductibility of such federal net operating losses is limited. Some but not all states conform to the federal treatment of net operating losses. As of December 31, 2021 and 2020, the Company had research and development tax credit carryforwards for federal tax purposes of $21.4 million and $11.9 million, and state research and development tax credit carryforwards of $15.9 million and $9.1 million, respectively. The federal research and development tax credit carryforwards will expire at various dates beginning in the year 2032. The Company’s state research and development tax credit carryforwards do not expire. Utilization of the net operating loss, or NOL, carryforwards and credits may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of NOL carryforwards and credits before utilization. Current laws impose substantial restrictions on the utilization of NOL carryforwards and credits in the event of an “ownership change” within a three-year period as defined by the Internal Revenue Code Section 382, or Section 382. If there should be an ownership change, the Company’s ability to utilize its NOL carryforwards and credits could be limited. The Company has not performed a Section 382 analysis. Realization of the future tax benefits is dependent on the Company’s ability to generate sufficient taxable income within the carryforward period. Due to the Company’s history of U.S. operating losses, the Company believes that the recognition of the deferred tax assets arising from the above-mentioned future tax benefits is currently not more likely than not to be realized and, accordingly, have provided a full valuation allowance against net U.S. deferred tax assets. The net change in total valuation allowance was an increase of $188.7 million, a decrease of $0.8 million and an increase of $59.0 million for the years ended December 31, 2021, 2020 and 2019, respectively. The Company has not recorded a provision for deferred U.S. tax expense that could result from the remittance of foreign undistributed earnings since the Company intends to reinvest the earnings in its foreign subsidiaries indefinitely. The Company has made an accounting policy election to treat Global Intangible Low-Taxed Income, or GILTI, taxes as a current period expense rather than including these amounts in the measurement of deferred taxes. Uncertain Tax Positions The Company records unrecognized tax benefits, where appropriate, for all uncertain income tax positions. The Company recorded unrecognized tax benefits for uncertain tax positions of $20.1 million and $11.3 million as of December 31, 2021 and 2020, respectively, of which an immaterial amount would impact the Company’s effective tax rate if recognized, because the benefit would be offset by an increase in the valuation allowance. A reconciliation of the beginning and ending balance of total unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Unrecognized tax benefits - Beginning of period $ 11,269 $ 6,543 $ 3,427 Increases related to current year’s tax positions 8,223 4,666 3,116 Increases related to prior years’ tax positions 608 60 — Unrecognized tax benefits - End of period $ 20,100 $ 11,269 $ 6,543 The Company’s policy is to recognize interest and penalties accrued on any unrecognized tax benefits as a component of income tax expense. During the years ended December 31, 2021, 2020 and 2019, the Company recognized no interest and penalties associated with unrecognized tax benefits. There are no tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within twelve months of the reporting date.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2021
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit PlanThe Company sponsors a 401(k) plan, and pursuant to its terms, eligible employees can elect to contribute to the 401(k) plan, subject to certain limitations, up to the lesser of the statutory maximum or 100% of eligible compensation on a pre-tax basis. For the years ended December 31, 2021, 2020 and 2019, the Company contributed $4.5 million, $2.8 million and $0.3 million, respectively, to match employee contributions as permitted by the plan. The Company pays the administrative costs for the plan.

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic Information The Company operates as one operating segment. The Company's chief operating decision makers are its Co-Chief Executive Officers, who review financial information presented on a consolidated basis for the purposes of making operating decisions, assessing financial performance and allocating resources. The following table sets forth the Company’s revenue by geographic areas based on the customers’ locations: Year Ended December 31, 2021 2020 2019 (in thousands) United States $ 352,561 $ 264,657 $ 194,312 International (1) 21,092 22,073 20,063 Total revenue $ 373,653 $ 286,730 $ 214,375 (1) No single country outside of the United States accounted for more than 10% of total revenue during each of the years ended December 31, 2021, 2020 and 2019.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions As discussed in Note 3, Investment in Joint Venture , the Company and an affiliate of SoftBank formed and capitalized the Joint Venture to accelerate commercialization of its products in Asia, the Middle East and Africa. The Company has consolidated the financial position, results of operations and cash flows of the Joint Venture in its financial statements and all intercompany balances have been eliminated in consolidation.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP. The accompanying consolidated financial statements include the accounts of Guardant Health, Inc., its consolidated Joint Venture and majority owned subsidiary. Other stockholders’ interests in the Joint Venture are shown in the consolidated financial statements as redeemable noncontrolling interest. All significant intercompany balances and transactions have been eliminated in consolidation. The Company believes that its existing cash and cash equivalents and marketable securities as of December 31, 2021 will be sufficient to allow the Company to fund its current operating plan through at least a period of one year after the date the accompanying consolidated financial statements are issued. As the Company continues to incur losses, its transition to profitability is dependent upon a level of revenues adequate to support the Company’s cost structure. If the Company’s transition to profitability is not consistent with its current operating plan, the Company may have to seek additional capital.
Use of Estimates	Use of Estimates The preparation of consolidated 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 consolidated financial statements, as well as the reported amounts of revenues and expenses during the periods presented. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Estimates are used in several areas including, but not limited to, estimation of variable consideration, estimation of credit losses,
Foreign Currency	Foreign Currency The functional currency of the subsidiaries of the consolidated Joint Venture is the local currency. The assets and liabilities of the subsidiaries are translated into U.S. dollars at exchange rates in effect at each balance sheet date, with the resulting translation adjustments recorded to a separate component of accumulated other comprehensive loss within stockholders’ equity. Income and expense accounts are translated at average exchange rates during the period. Foreign currency transaction gains and losses resulting from transactions denominated in a currency other than the functional currency are recognized in the consolidated statements of operations. For the year ended December 31, 2021, 2020 and 2019, foreign currency transaction gains and losses were immaterial.
Segment Information	Segment Information The Company operates as one operating and reportable segment. The Company's chief operating decision makers are its Co-Chief Executive Officers, who review financial information presented on a consolidated basis for the purposes of making operating decisions, assessing financial performance and allocating resources.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash Cash equivalents consist of highly liquid investments with original maturities at the time of purchase of three months or less. Cash equivalents include bank demand deposits and money market accounts that invest primarily in U.S. government-backed securities and treasuries. Cash equivalents are carried at cost, which approximates their fair value.
Marketable Securities	Marketable Securities Marketable securities consist primarily of high-grade U.S. government and agency securities and corporate bonds. Marketable securities with original maturities at the time of purchase between three and twelve months from balance sheet dates are classified as short-term marketable securities and those with maturities over twelve months from balance sheet dates are classified as long-term marketable securities. The Company classifies all marketable securities as available-for-sale, which are recorded at fair value. Unrealized gains and losses are included in accumulated other comprehensive gain (loss) in stockholders’ equity. Any premium or discount arising at purchase is amortized or accreted to interest income or expense. The Company periodically evaluates its available-for-sale marketable securities for impairment. Prior to the adoption of Accounting Standards Update, or ASU, 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments , the Company assesses whether declines in fair values of its marketable securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the marketable security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not that it will be required to sell any marketable securities before recovery of its amortized cost basis. Factors considered include quoted market prices, recent financial results and operating trends, implied values from any recent transactions or offers of investee securities, credit quality of debt instrument issuers, other publicly available information that may affect the value of the marketable security, duration and severity of the decline in value, and management’s strategy and intentions for holding the marketable security. Realized gains and losses and declines in value, if any, judged to be other than temporary on available‑for‑sale securities are reported in other income (expense), net on the consolidated statements of operations. When securities are sold, any associated unrealized gain or loss initially recorded as a separate component of stockholders’ equity is reclassified out of stockholders’ equity on a specific‑identification basis and recorded in earnings for the period. Starting January 1, 2020, upon adoption of ASU 2016-13, when the fair value of a marketable security is below its amortized cost, the amortized cost is reduced to its fair value if it is more likely than not that the Company is required to sell the impaired security before recovery of its amortized cost basis, or the Company has the intention to sell the security. If neither of these conditions are met, the Company determines whether the impairment is due to credit losses by comparing the present value of the expected cash flows of the security with its amortized cost basis. The amount of impairment recognized is limited to the excess of the amortized cost over the fair value of the security. An allowance for credit losses for the excess of amortized cost over the expected cash flows is recorded in other income (expense), net on the consolidated statements of operations. Impairment losses that are not credit-related are included in accumulated other comprehensive gain (loss) in stockholders’ equity.
Non Marketable Securities	Non-Marketable SecuritiesThe Company acquires certain equity investments in private companies to promote business and strategic objectives. The Company's investments in non-marketable equity securities do not give the Company the ability to control or exercise significant influence over the investee. The Company's non-marketable equity and other related investments totaled $39.4 million as of December 31, 2021, and are included in other assets, net on the accompanying consolidated balance sheets. The Company did not have such non-marketable equity and other related investments as of December 31, 2020. Non-marketable securities are subject to periodic impairment reviews and adjustments for observable price changes from orderly transactions. The Company's evaluation of impairment of such non-marketable securities is based on adverse changes in market conditions and the regulatory or economic environment, qualitative and quantitative analysis of the operating performance of the investee; changes in operating structure or management of the investee; additional funding requirements; and the investee’s ability to remain in business. Pursuant to one of the investments in non-marketable securities purchased by the Company, and subject to the Company purchasing additional non-marketable securities from the same investee, the Company would acquire rights to purchase the investee at a pre-determined price subject to additional adjustments based on the performance of the investee, on or before December 31, 2022. As of December 31, 2021, no impairment or adjustments to carrying value of non-marketable securities have been recorded. The Company’s assessment of these factors in determining whether an impairment exists could change in the future due to new developments or changes in applied assumptions.
Concentration of Risk	Concentration of Risk The Company is subject to credit risk from its portfolio of cash equivalents held at one commercial bank and investments in marketable securities. The Company limits its exposure to credit losses by investing in money market funds through a U.S. bank with high credit ratings. The Company’s cash may consist of deposits held with banks that may at times exceed federally insured limits, however, its exposure to credit risk in the event of default by the financial institution is limited to the extent of amounts recorded on the consolidated balance sheets. The Company performs evaluations of the relative credit standing of these financial institutions to limit the amount of credit exposure. The Company also invests in investment‑grade debt instruments and has policy limits for the amount it can invest in any one type of security, except for securities issued or guaranteed by the U.S. government. The goals of the Company’s investment policy, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements; and a competitive after‑tax rate of return. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, investment type and issuer, as a result, the Company is not exposed to any significant concentrations of credit risk from these financial instruments. The Company is subject to credit risk from its accounts receivable. The majority of the Company’s accounts receivable arises from the provision of precision oncology services and development services and other in the United States and are primarily with biopharmaceutical companies with high credit ratings. The Company has not experienced any material losses related to receivables from individual customers, or groups of customers. The Company does not require collateral. Accounts receivable are recorded at net amount.
Accounts Receivable, Net	Accounts Receivable, Net Accounts receivable represent valid claims against commercial and governmental payers, biopharmaceutical companies, research institutes and international distributors, including unbilled receivables, and royalty payments due from third parties for licensing the Company’s technologies. Unbilled receivables include balances due from biopharmaceutical customers related to development services and other revenues that are recognized upon the achievement of performance-based milestones but prior to the achievement of contractual billing rights. As of December 31, 2021 and 2020, the Company had unbilled receivables of $5.7 million and $1.4 million, respectively. The Company evaluates the collectability of its accounts receivable based on historical collection trends, the financial condition of payment partners, and external market factors and provides for an allowance for potential credit losses based on management’s best estimate of the amount of probable credit losses. As of December 31, 2021 and 2020, the Company had immaterial allowance for credit losses related to its accounts receivable.
Inventory	Inventory Inventories are stated at the lower of cost or net realizable value on a first-in, first-out basis. Inventory consisted entirely of supplies, which are consumed when providing tests, and therefore the Company does not maintain any finished goods inventory. In order to assess the ultimate realization of inventories, the Company is required to make judgments as to future demand requirements compared to current or committed inventory levels. The Company periodically reviews its
Property and Equipment, Net	Property and Equipment, Net Property and equipment are recorded at cost. Depreciation is computed over estimated useful lives of the related assets using the straight-line method. Leasehold improvements are amortized using the straight-line method over the estimated useful lives of the assets or the remaining term of the lease, whichever is shorter. The Company periodically reviews the depreciable lives assigned to property and equipment placed in service and changes the estimates of useful lives, if necessary. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed as incurred.
Asset Acquisition	Asset Acquisition If an acquisition of an asset or group of assets does not meet the definition of a business, the transaction is accounted for as an asset acquisition rather than a business combination. An asset acquisition does not result in the recognition of goodwill and transaction costs are capitalized as part of the cost of the asset or group of assets acquired. Transaction costs allocated to in-process research and development technology with no future alternate use is expensed as incurred. The total consideration is allocated to the various intangible assets acquired on a relative fair value basis. Cash paid in connection of purchase of in-process research and development technology in an asset acquisition is presented within the investing section of the consolidated statement of cash flows.
Goodwill and Intangible Assets, net	Goodwill and Intangible Assets, net Intangible assets related to in-process research and development costs, or IPR&D, acquired in a business combination are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts. If and when development is complete, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. Prior to completion of the research and development efforts, the assets are considered indefinite-lived. During this period, the assets will not be amortized but will be tested for impairment on an annual basis and between annual tests if we become aware of any events occurring or changes in circumstances that would indicate a reduction in the fair value of the IPR&D projects below their respective carrying amounts. Goodwill represents the excess of the purchase price over the fair value of net identifiable assets and liabilities. Goodwill and IPR&D are not amortized but are tested for impairment at least annually during the fourth fiscal quarter, or if circumstances indicate their value may no longer be recoverable. The Company continues to operate in one segment, which is considered to be the sole reporting unit and, therefore, goodwill was tested for impairment at the enterprise level. As of December 31, 2021, there has been no impairment of goodwill or IPR&D.
Impairment for Long-Lived Assets	Impairment for Long-Lived Assets The Company evaluates long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the asset may not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than its carrying amount. Impairment, if any, is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value.
Leases	Leases The Company determines if an arrangement contains a lease at inception. Operating lease right-of-use, or ROU, assets and operating leases liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. ROU assets also include any initial direct costs incurred and any lease payments made at or before the lease commencement date, less lease incentives received or receivable. The Company uses its incremental borrowing rate based on the information available at the commencement date in determining the lease liabilities, as the Company's leases generally do not provide an implicit rate. Lease terms may include options to extend or terminate when the Company is reasonably certain the option will be exercised. Lease expense is recognized on a straight-line basis over the lease term. The Company also has lease arrangements with lease and non-lease components. The Company elected the practical expedient not to separate non-lease components from lease components for the Company’s facility leases. The Company also elected to apply the short-term lease measurement and recognition exemption in which ROU assets and lease liabilities are not recognized for leases with terms of 12 months or less.
Convertible Senior Notes	Convertible Senior Notes In accounting for the issuance of the convertible senior notes, the Company separates the notes into liability and equity components. The carrying amount of the liability component is calculated by measuring the fair value of a similar liability that does not have an associated convertible feature, using a discounted cash flow model with a risk adjusted yield. The carrying amount of the equity component representing the conversion option is determined by deducting the fair value of the liability component from the par value of the notes as a whole. This difference represents a debt discount that is amortized to interest expense using the effective interest method over the term of the notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the transaction costs related to the issuance of the notes, the Company allocated the total amount incurred to the liability and equity components based on their relative fair values. Transaction costs attributable to the liability component are netted with the liability component and amortized to interest expense using the effective interest method over the term of the notes. Transaction costs attributable to the equity component are netted with the equity component of the notes in additional paid-in capital in the consolidated balance sheets. Starting January 1, 2021, upon early adoption of ASU 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, the carrying amount of the equity component of the cash conversion feature including the allocated debt issuance costs were reclassified from additional paid-in capital to convertible senior notes, net.
Revenue Recognition	Revenue Recognition The Company derives revenue from the provision of precision oncology testing services provided to its ordering physicians and biopharmaceutical customers, as well as from biopharmaceutical research and development services provided to its biopharmaceutical customers. Precision oncology testing services include genomic profiling and the delivery of other genomic information derived from the Company’s platform. Development services and other include companion diagnostic development, clinical study setup, monitoring and maintenance, information solutions and laboratory services, and other miscellaneous revenue streams. The Company currently receives payments from third-party commercial and governmental payers, certain hospitals and oncology centers and individual patients, as well as biopharmaceutical companies, research institutes and international distributors. Effective January 1, 2019, the Company adopted the new revenue recognition standard, FASB ASC Topic 606, Revenue from Contracts with Customers, or ASC 606 . Revenues are recognized when control of services is transferred to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. ASC 606 provides for a five-step model that includes identifying the contract with a customer, identifying the performance obligations in the contract, determining the transaction price, allocating the transaction price to the performance obligations, and recognizing revenue when, or as, an entity satisfies a performance obligation. Precision oncology testing The Company recognizes revenue from the sale of its precision oncology tests for clinical customers, including certain hospitals, cancer centers, other institutions and patients, at the time results of the test are reported to physicians. Most precision oncology tests requested by clinical customers are sold without a written agreement; however, the Company determines an implied contract exists with its clinical customers. The Company identifies each sale of its test to clinical customer as a single performance obligation. With the exception of certain limited contracted arrangements with insurance carriers and other institutions where the transaction price is fixed, a stated contract price does not exist and the transaction price for each implied contract with clinical customers represents variable consideration. The Company estimates the variable consideration under the portfolio approach and considers the historical reimbursement data from third-party commercial and governmental payers and patients, as well as known or anticipated reimbursement trends not reflected in the historical data. The Company monitors the estimated amount to be collected in the portfolio at each reporting period based on actual cash collections in order to assess whether a revision to the estimate is required. Both the estimate and any subsequent revision contain uncertainty and require the use of significant judgment in the estimation of the variable consideration and application of the constraint for such variable consideration. The Company analyzes its actual cash collections over the expected reimbursement period and compares it with the estimated variable consideration for each portfolio and any difference is recognized as an adjustment to estimated revenue after the expected reimbursement period, subject to assessment of the risk of future revenue reversal. For the year ended December 31, 2021, 2020 and 2019, the Company recorded $19.3 million, $26.0 million and $16.8 million as revenue, respectively, resulting from cash collections exceeding the estimated variable consideration related to samples processed in previous years, including revenue received from successful appeals of reimbursement denials, net of recoupments. Revenue from sales of precision oncology tests to biopharmaceutical customers are based on a negotiated price per test or on the basis of an agreement to provide certain testing volume over a defined period. The Company identifies its promise to transfer a series of distinct tests to biopharmaceutical customers as a single performance obligation. Precision oncology tests to biopharmaceutical customers are generally billed at a fixed price for each test performed. For agreements involving testing volume to be satisfied over a defined period, revenue is recognized over time based on the number of tests performed as the performance obligation is satisfied over time. Results of the Company’s precision oncology services are delivered electronically, and as such there are no shipping or handling fees incurred by the Company or billed to customers. Development services and other The Company performs development services for its biopharmaceutical customers utilizing its precision oncology information platform. Development services typically represent a single performance obligation as the Company performs a significant integration service, such as analytical validation and regulatory submissions. The individual promises are not separately identifiable from other promises in the contracts and, therefore, are not distinct. However, under certain contracts, a biopharmaceutical customer may engage the Company for multiple distinct development services which are both capable of being distinct and separately identifiable from other promises in the contracts and, therefore, distinct performance obligations. The Company collaborates with pharmaceutical companies in the development of new drugs. As part of these collaborations, the Company provides services related to regulatory filings to support companion diagnostic device submissions for the Company’s testing panels. Under these collaborations, the Company generates revenue from achievement of milestones, as well as provision of on-going support. For development services performed, the Company is compensated through a combination of an upfront fee and performance-based, non-refundable regulatory and other developmental milestone payments. The transaction price of the Company's development services contracts typically represents variable consideration. Application of the constraint for variable consideration to milestone payments is an area that requires significant judgment. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be managed to achieve the respective milestone and the level of effort and investment required to achieve the respective milestone. In making this assessment, the Company considers its historical experience with similar milestones, the degree of complexity and uncertainty associated with each milestone, and whether achievement of the milestone is dependent on parties other than the Company. The constraint for variable consideration is applied such that it is probable a significant reversal of revenue will not occur when the uncertainty associated with the contingency is resolved. Application of the constraint for variable consideration is assessed and updated at each reporting period as a revision to the estimated transaction price. The Company recognizes development services revenue over the period in which biopharmaceutical research and development services are provided. Specifically, the Company recognizes revenue using an input method to measure progress, utilizing costs incurred to-date relative to total expected costs as its measure of progress. The Company assesses the changes to the total expected cost estimates as well as any incremental fees negotiated resulting from changes to the scope of the original contract in determining the revenue recognition at each reporting period. For development of new products or services under these arrangements, costs incurred before technological feasibility is reached are included as research and development expenses in the Company’s consolidated statements of operations, while costs incurred thereafter are recorded as cost of development services and other. The Company also has other miscellaneous revenue streams that are recognized in addition to development services noted above such as clinical study setup, monitoring and maintenance, testing development and support, GuardantConnect, GuardantINFORM, and kits fulfillment related revenues. In addition, the Company derives sales- based royalty revenues from licensing its technologies. Revenues related to clinical study setup, monitoring and maintenance, testing development and support, GuardantConnect, GuardantINFORM are generally recognized over time based on an input method to measure progress in the period when the associated services have been performed. Kits fulfillment related revenues are recognized when such products are delivered. Royalty revenues are recognized when actual sales incur. Contracts with multiple performance obligations Contracts with biopharmaceutical customers may include multiple distinct performance obligations, such as provision of precision oncology testing, biopharmaceutical research and development services, and clinical study enrollment assistance, among others. The Company evaluates the terms and conditions included within its contracts with biopharmaceutical customers to ensure appropriate revenue recognition, including whether services are considered distinct performance obligations that should be accounted for separately versus together. The Company first identifies material promises, in contrast to immaterial promises or administrative tasks, under the contract, and then evaluates whether these promises are both capable of being distinct and distinct within the context of the contract. In assessing whether a promised service is capable of being distinct, the Company considers whether the customer could benefit from the service either on its own or together with other resources that are readily available to the customer, including factors such as the research, development, and commercialization capabilities of a third party as well as the availability of the associated expertise in the general marketplace. In assessing whether a promised service is distinct within the context of the contract, the Company considers whether it provides a significant integration of the services, whether the services significantly modify or customize one another, or whether the services are highly interdependent or interrelated. For contracts with multiple performance obligations, the transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. The Company determines standalone selling price by considering the historical selling price of these performance obligations in similar transactions as well as other factors, including, but not limited to, the price that customers in the market would be willing to pay, competitive pricing of other vendors, industry publications and current pricing practices, and expected costs of satisfying each performance obligation plus appropriate margin. Deferred revenue Deferred revenue, which is a contract liability, consists primarily of payments received in advance of revenue recognition from contracts with customers. For example, development services and other contracts with biopharmaceutical customers often contain upfront payments which results in the recording of deferred revenue to the extent cash is received prior to the Company’s performance of the related services. Contract liabilities are relieved as the Company performs its obligations under the contract and revenue is consequently recognized. As of December 31, 2021 and 2020, the deferred revenue balance was $11.3 million and $8.6 million, respectively, which included $3.5 million and $3.0 million, respectively, related to collaboration development efforts with pharmaceutical companies to be recognized as the Company performs research and development services in the future periods. Revenue recognized in the year ended December 31, 2021 that was included in the deferred revenue balance as of December 31, 2020 was $8.3 million, of which $3.0 million represented revenue from provision of development services under the collaboration agreements with biopharmaceutical customers. Revenue recognized in the year ended December 31, 2020 that was included in the deferred revenue balance as of January 1, 2020 was $10.2 million, of which $4.8 million represented revenue from provision of development services under the collaboration agreements with biopharmaceutical customers. Transaction price allocated to the remaining performance obligations Transaction price allocated to remaining performance obligations represents contracted revenue that has not yet been recognized, which includes deferred revenue and non-cancelable amounts that will be invoiced and recognized as revenues in future periods. The Company expects to recognize substantially all of the remaining transaction price in the next 12 months.
Costs of Precision Oncology Testing	Costs of Precision Oncology Testing Cost of precision oncology testing generally consists of cost of materials, direct labor including bonus, benefit and stock-based compensation, equipment and infrastructure expenses associated with processing test samples (including sample accessioning, library preparation, sequencing, quality control analyses and shipping charges to transport blood samples), freight, curation of test results for physicians and license fees due to third parties. Infrastructure expenses include depreciation of laboratory equipment, rent costs, amortization of leasehold improvements and information technology costs. Costs associated with performing the Company’s tests are recorded as the tests are performed regardless of whether revenue was recognized with respect to that test. Royalties for licensed technology
Cost of Development Services and Other	Cost of Development Services and Other Cost of development service and other primarily includes costs incurred for the performance of development services requested by the Company’s biopharmaceutical customers and other revenues included as noted above. For development of new products, costs incurred before technological feasibility has been achieved are reported as research and development expenses, while costs incurred thereafter are reported as cost of development services and other.
Research and Development Expenses	Research and Development Expenses Research and development expenses are comprised of costs incurred to develop technology and include compensation and benefits, reagents and supplies used in research and development laboratory work, infrastructure expenses, including allocated facility occupancy and information technology costs, contract services and other outside costs. Research and development costs are expensed as incurred. Payments made prior to the receipt of goods or services to be used in research and development are deferred and recognized as expense in the period in which the related goods are received or services are rendered. Costs to develop the Company’s technology capabilities are recorded as research and development unless they meet the criteria to be capitalized as internal-use software costs.
Advertising	AdvertisingThe Company expenses advertising costs as incurred.
Stock-Based Compensation	Stock‑Based Compensation Stock‑based compensation related to stock options granted to the Company’s and the Joint Venture's employees, directors and nonemployees is measured at the grant date based on the fair value of the award. The fair value is recognized as expense over the requisite service period, which is generally the vesting period of the respective awards. Compensation expense for stock options with performance metrics is calculated based upon expected achievement of the metrics specified in the grant. Starting January 1, 2019, upon adoption of ASU 2018-07, Compensation - Stock Compensation (Topic 718), Improvements to Nonemployee Share-Based Payment Accounting , the fair value of stock options issued to nonemployee consultants is determined as of the grant date, and compensation expense is being recognized over the period that the related services are rendered. The Company uses the Black‑Scholes option‑pricing model to estimate the fair value of stock options granted under the 2012 Stock Plan, the 2018 Incentive Award Plan, and the Joint Venture's 2020 Equity Incentive Plan, and stock purchase rights granted under the 2018 Employee Stock Purchase Plan. The Black-Scholes option-pricing model requires assumptions to be made related to the expected term of an award, expected volatility, risk-free rate and expected dividend yield. The board of directors of the Joint Venture has determined the fair value of common stock of the Joint Venture. Forfeitures are accounted for as they occur. For market-based restricted stock units, the Company derives the requisite service period using the Monte Carlo simulation model and the related compensation expense is recognized over the derived service period using an accelerated attribution model commencing on the grant date. Stock-based compensation expense will be recorded regardless of whether the market conditions are achieved or not. If the related market condition is achieved earlier than its estimated derived service period, the stock-based compensation expense will be accelerated, and a cumulative catch-up expense will be recorded during the period in which the market condition is met.
Income Taxes	Income Taxes Income taxes are recorded using an asset and liability approach. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Tax benefits are recognized when it is more likely than not that a tax position will be sustained during an audit. Deferred tax assets are reduced by a valuation allowance if current evidence indicates that it is considered more likely than not that these benefits will not be realized. The Company’s tax positions are subject to income tax audits. The Company recognizes the tax benefit of an uncertain tax position only if it is more likely than not that the position is sustainable upon examination by the taxing authority, based on the technical merits. The tax benefit recognized is measured as the largest amount of benefit which is more likely than not to be realized upon settlement with the taxing authority. The Company recognizes interest accrued and penalties related to unrecognized tax benefits in its tax provision. The Company evaluates uncertain tax positions on a regular basis. The evaluations are based on a number of factors, including changes in facts and circumstances, changes in tax law, correspondence with tax authorities during the course of the audit, and effective settlement of audit issues. The provision for income taxes includes the effects of any accruals that the Company believes are appropriate, as well as the related net interest and penalties.
Net Loss Per Share Attributable to Common Shareholders	Net Loss Per Share Attributable to Common Stockholders The Company calculates basic net loss per share attributable to common stockholders by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period determined using the treasury stock method or the as-if converted method, as appropriate. For purposes of this calculation, stock options, restricted stock units, shares issuable pursuant to the employee stock purchase plan, shares subject to repurchase from early exercised options and contingently issuable shares under the convertible senior notes are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive.
Accounting Pronouncements Adopted	Accounting Pronouncements Adopted Convertible Instruments and Contracts in an Entity’s Own Equity In August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (ASU 2020-06) , which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity’s own equity. Among other changes, ASU 2020-06 removes the liability and equity separation model for convertible instruments with a cash conversion feature, and as a result, after adoption, entities will no longer separately present in equity an embedded conversion feature for such debt. Similarly, the embedded conversion feature will no longer be amortized as interest expense over the life of the instrument. Instead, entities will account for a convertible debt instrument wholly as debt unless (1) a convertible instrument contains features that require bifurcation as a derivative under ASC Topic 815, Derivatives and Hedging, or (2) a convertible debt instrument was issued at a substantial premium. Among other potential impacts, this change is expected to reduce reported interest expense, increase reported net income, and result in a reclassification of certain conversion feature balance sheet amounts from stockholders’ equity to liabilities as it relates to the Company’s convertible senior notes. Additionally, ASU 2020-06 requires the application of the if-converted method to calculate the impact of convertible instruments on diluted earnings per share. The Company early adopted ASU 2020-06 in the first quarter of fiscal 2021 using the modified retrospective approach which resulted in the re-classification of the carrying amount of the equity component of the cash conversion feature including the allocated debt issuance costs as of December 31, 2020, from additional paid-in capital to convertible senior notes, net.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedules of Concentration of Risk, by Risk Factor	A significant customer is a biopharmaceutical customer or a clinical testing payer that represents 10% or more of the Company’s total revenue or accounts receivable balance. Revenue attributable to each significant customer, including its affiliated entities, as a percentage of the Company’s total revenue, for the respective period, and accounts receivable balance attributable to each significant customers, including its affiliated entities, as a percentage of the Company’s total accounts receivable balance, at the respective consolidated balance sheet date, are as follows: Revenue Accounts Receivable, Net Year Ended December 31, As of December 31, 2021 2020 2019 2021 2020 Customer A * 10 % 26 % * 11 % Customer B 29 % 25 % 14 % 13 % 13 % Customer C * * * 10 % 12 % Customer D * * * * 11 % Customer E * * * 13 % * * less than 10%
Contractual Receivables, Allowance For Credit Loss	The following table presents the receivable and the related credit loss amounts: Gross Amount Allowance for Credit Losses Net Amount December 31, 2021 December 31, 2020 Year Ended December 31, 2021 December 31, 2021 December 31, 2020 Beginning Balance Charged to (Reversed from) Other Income (Expense), Net Reclassi Ending Balance (in thousand) Prepaid expenses and other current assets $ — $ — $ — $ 1,100 $ (1,100) $ — $ — $ — Other assets 5,900 7,000 (7,000) — 1,100 (5,900) — —
Property, Plant and Equipment	Estimated useful lives for property and equipment are as follows: Property and Equipment Estimated Useful Life Machinery and equipment 3 – 5 years Furniture and fixtures 7 years Computer hardware and computer software 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term Property and equipment, net consist of the following: As of December 31, 2021 2020 (in thousands) Machinery and equipment $ 63,022 $ 40,216 Leasehold improvements 38,702 34,037 Computer hardware 16,685 10,862 Construction in progress (1) 55,873 7,833 Furniture and fixtures 3,683 3,043 Computer software 1,320 1,136 Property and equipment, gross $ 179,285 $ 97,127 Less: accumulated depreciation (54,824) (34,345) Property and equipment, net $ 124,461 $ 62,782

Consolidated Balance Sheet Co_2

Consolidated Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Property, Plant and Equipment	Estimated useful lives for property and equipment are as follows: Property and Equipment Estimated Useful Life Machinery and equipment 3 – 5 years Furniture and fixtures 7 years Computer hardware and computer software 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term Property and equipment, net consist of the following: As of December 31, 2021 2020 (in thousands) Machinery and equipment $ 63,022 $ 40,216 Leasehold improvements 38,702 34,037 Computer hardware 16,685 10,862 Construction in progress (1) 55,873 7,833 Furniture and fixtures 3,683 3,043 Computer software 1,320 1,136 Property and equipment, gross $ 179,285 $ 97,127 Less: accumulated depreciation (54,824) (34,345) Property and equipment, net $ 124,461 $ 62,782
Schedule of Accrued Liabilities	Accrued expenses consist of the following: As of December 31, 2021 2020 (in thousands) Operating lease liabilities $ 12,856 $ 6,632 Accrued tax liabilities 4,223 4,634 Accrued professional services 6,994 3,397 Accrued clinical studies 3,332 1,264 Accrued legal expenses 4,166 2,875 Purchases of property and equipment included in accrued expenses 5,893 1,156 Others 7,821 2,681 Total accrued expenses $ 45,285 $ 22,639

Fair Value Measurements. Cash_2

Fair Value Measurements. Cash Equivalents and Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The Company’s financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows: December 31, 2021 Fair Value Level 1 Level 2 Level 3 (in thousands) Financial Assets: Money market funds $ 357,785 $ 357,785 $ — $ — Total cash equivalents $ 357,785 $ 357,785 $ — $ — U.S. government debt securities $ 440,546 $ — $ 440,546 $ — Total short-term marketable securities $ 440,546 $ — $ 440,546 $ — U.S. government debt securities $ 698,034 $ — $ 698,034 $ — Total long-term marketable securities $ 698,034 $ — $ 698,034 $ — Total $ 1,496,365 $ 357,785 $ 1,138,580 $ — Financial Liabilities: Contingent consideration $ 3,625 $ — $ — $ 3,625 Total $ 3,625 $ — $ — $ 3,625 December 31, 2020 Fair Value Level 1 Level 2 Level 3 (in thousands) Financial Assets: Money market funds $ 620,630 $ 620,630 $ — $ — Total cash equivalents $ 620,630 $ 620,630 $ — $ — U.S. government debt securities 961,902 — 961,902 — Total short-term marketable securities $ 961,902 $ — $ 961,902 $ — U.S. government debt securities $ 246,597 $ — $ 246,597 $ — Total long-term marketable securities $ 246,597 $ — $ 246,597 $ — Total $ 1,829,129 $ 620,630 $ 1,208,499 $ — Financial Liabilities: Contingent consideration $ 1,245 $ — $ — $ 1,245 Total $ 1,245 $ — $ — $ 1,245
Schedule of Level 3 Activity	The following tables summarize the activities for the Level 3 financial instruments for the years ended December 31, 2021, 2020 and 2019: Contingent Consideration Year Ended December 31, 2021 2020 2019 (in thousands) Fair value — beginning of period $ 1,245 $ 1,365 $ — Initial valuation on the date of acquisition — — 1,065 Increase (decrease) in fair value 2,380 (120) 300 Fair value — end of period $ 3,625 $ 1,245 $ 1,365 Noncontrolling Interest Liability Redeemable Noncontrolling Interest Year Ended December 31, Year Ended December 31, 2021 2021 2020 2019 (in thousands) Fair value — beginning of period $ — $ 57,100 $ 49,600 $ 41,800 Increase in fair value — 27,244 12,934 11,659 Net loss for the period — (6,344) (5,434) (3,859) Reclassification of redeemable noncontrolling interest to noncontrolling interest liability 78,000 (78,000) — — Fair value — end of period $ 78,000 $ — $ 57,100 $ 49,600
Debt Securities, Available-for-sale	The following tables summarizes the Company’s cash equivalents and marketable securities’ amortized costs, gross unrealized gains, gross unrealized losses and estimated fair values by significant investment category: December 31, 2021 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Estimated Fair Value (in thousands) Money market fund $ 357,785 $ — $ — $ 357,785 U.S. government debt securities 1,142,172 2 (3,594) 1,138,580 Total $ 1,499,957 $ 2 $ (3,594) $ 1,496,365 December 31, 2020 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Estimated Fair Value (in thousands) Money market fund $ 620,630 $ — $ — $ 620,630 U.S. government debt securities 1,206,195 2,339 (35) 1,208,499 Total $ 1,826,825 $ 2,339 $ (35) $ 1,829,129

Intangible Assets, Net and Go_2

Intangible Assets, Net and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following table presents details of purchased intangible assets as of December 31, 2021 and 2020: December 31, 2021 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Remaining Weighted-Average Useful Life (in thousands) (in years) Intangible assets subject to amortization: Acquired license $ 11,886 $ (2,473) $ 9,413 8.8 Non-compete agreements and other covenant rights 5,100 (1,906) 3,194 3.9 Total intangible assets subject to amortization 16,986 (4,379) 12,607 Intangible assets not subject to amortization: IPR&D 1,600 — 1,600 Goodwill 3,290 — 3,290 Total purchased intangible assets $ 21,876 $ (4,379) $ 17,497 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Remaining Weighted-Average Useful Life (in thousands) (in years) Intangible assets subject to amortization: Acquired license $ 11,886 $ (1,367) $ 10,519 9.8 Non-compete agreements and other covenant rights 5,100 (1,064) 4,036 4.9 Total intangible assets subject to amortization 16,986 (2,431) 14,555 Intangible assets not subject to amortization: IPR&D 1,600 — 1,600 Goodwill 3,290 — 3,290 Total purchased intangible assets $ 21,876 $ (2,431) $ 19,445
Schedule of Indefinite-Lived Intangible Assets	The following table presents details of purchased intangible assets as of December 31, 2021 and 2020: December 31, 2021 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Remaining Weighted-Average Useful Life (in thousands) (in years) Intangible assets subject to amortization: Acquired license $ 11,886 $ (2,473) $ 9,413 8.8 Non-compete agreements and other covenant rights 5,100 (1,906) 3,194 3.9 Total intangible assets subject to amortization 16,986 (4,379) 12,607 Intangible assets not subject to amortization: IPR&D 1,600 — 1,600 Goodwill 3,290 — 3,290 Total purchased intangible assets $ 21,876 $ (4,379) $ 17,497 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Remaining Weighted-Average Useful Life (in thousands) (in years) Intangible assets subject to amortization: Acquired license $ 11,886 $ (1,367) $ 10,519 9.8 Non-compete agreements and other covenant rights 5,100 (1,064) 4,036 4.9 Total intangible assets subject to amortization 16,986 (2,431) 14,555 Intangible assets not subject to amortization: IPR&D 1,600 — 1,600 Goodwill 3,290 — 3,290 Total purchased intangible assets $ 21,876 $ (2,431) $ 19,445
Schedule of Future Amortization Expense	The following table summarizes estimated future amortization expense of finite-lived intangible assets, net: Year Ending December 31, (in thousands) 2022 1,947 2023 1,947 2024 1,953 2025 1,670 2026 1,212 2027 and thereafter 3,878 Total $ 12,607

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instrument Components	The following table sets forth the components of the 2027 Notes as of December 31, 2021 and 2020: As of December 31, 2021 2020 (in thousands) Liability component: Principal $ 1,150,000 $ 1,150,000 Less: debt discount, net of amortization — (331,074) Less: debt issuance costs, net of amortization (15,179) (12,634) Net carrying amount $ 1,134,821 $ 806,292 Equity component recorded at issuance: 2027 Notes $ — $ 335,667 Less: issuance costs — (5,264) Net amount recorded in equity $ — $ 330,403
Schedule of Interest Expense	The following table sets forth interest expense recognized related to the Notes for the year ended December 31, 2021 and 2020: For the Year Ended December 31, 2021 2020 (in thousands) Amortization of debt discount $ — 4,593 Amortization of debt issuance costs 2,564 136 Total interest expense recognized $ 2,564 $ 4,729 Effective interest rate of the liability component 0.2 % 5.2 %

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Lease Information	As of December 31, 2021 2020 Weighted-average remaining lease term (in years) 10.0 5.5 Weighted-average discount rate 4.01 % 8.07 %
Schedule of Operating Lease Liability Maturities	The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of December 31, 2021: Year Ending December 31, (in thousands) 2022 $ 18,840 2023 29,056 2024 31,584 2025 32,063 2026 27,753 2027 and thereafter 149,637 Total operating lease payments $ 288,933 Less: Imputed Interest (50,024) Total operating lease liabilities $ 238,909

Common Stock (Tables)

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	The Company’s common stock has been reserved for the following potential future issuances: As of December 31, 2021 2020 Shares underlying outstanding stock options 2,624,974 3,101,181 Shares underlying unvested restricted stock units 1,498,553 1,118,655 Market-based restricted stock units 2,260,764 3,391,148 Performance-based restricted stock units 374,596 377,922 Shares available for issuance under the 2018 Incentive Award Plan 5,231,624 1,819,223 Shares available for issuance under the 2018 Employee Stock Purchase Plan 1,426,264 1,536,491 Total 13,416,775 11,344,620

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	A summary of the Company’s stock option activity under the 2012 Plan and the 2018 Plan and related information is as follows: Options Outstanding Shares Shares Subject to Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 1, 2019 3,556,507 7,588,405 $ 4.58 8.3 $ 250,495 Granted (324,579) 324,579 88.18 Exercised — (2,999,419) 3.87 Canceled 12,636 (418,676) 6.64 Restricted stock units granted (567,425) — Restricted stock units canceled 49,086 — Balance as of December 31, 2019 2,726,225 4,494,889 10.90 7.7 306,392 2018 Plan annual increase (1) 3,689,000 — Granted (127,590) 127,590 81.78 Exercised — (1,446,843) 6.59 Canceled 20,370 (74,455) 12.13 Restricted stock units granted (823,454) — Restricted stock units canceled 103,742 — Market-based restricted stock units granted (3,391,148) — Performance-based restricted stock units granted (377,922) — Balance as of December 31, 2020 1,819,223 3,101,181 15.80 6.9 350,670 2018 Plan annual increase (1) 3,689,000 — Granted (345,774) 345,774 119.82 Exercised — (693,074) 11.19 Canceled 65,523 (128,907) 47.51 Restricted stock units granted (873,916) — Restricted stock units canceled 315,988 — Market-based restricted stock units granted — — Market-based restricted stock units canceled 558,254 — Performance-based restricted stock units granted (52,917) — Performance-based restricted stock units canceled 56,243 — Balance as of December 31, 2021 5,231,624 2,624,974 $ 29.17 6.5 $ 193,014 Vested and Exercisable as of December 31, 2021 1,973,789 $ 11.05 5.8 $ 175,783 (1) Effective as of January 1, 2020, an additional 3,689,000 shares of common stock became available for issuance under the 2018 Plan, as a result of the operation of an automatic annual increase provision therein. Options Outstanding Shares Shares Subject to Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 1, 2020 — — $ — 0.0 $ — Shares authorized 4,595,555 — — Granted (4,062,224) 4,062,224 0.58 Canceled 8,889 (8,889) — Balance as of December 31, 2020 542,220 4,053,335 0.58 9.6 — Granted (826,667) 826,667 0.58 Exercised — (602,408) 0.58 Canceled 625,375 (625,375) 0.58 Balance as of December 31, 2021 340,928 3,652,219 $ 0.58 8.8 $ — Vested and Exercisable as of December 31, 2021 2,148,474 $ 0.58 8.6 $ —
Schedule of Restricted Stock Unit Activity	A summary of the Company’s restricted stock unit activity excluding the performance-based and market-based restricted stock units under the 2012 Plan and the 2018 Plan and related information is as follows: Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of January 1, 2019 — $ — Granted 567,425 78.61 Vested and released (22,208) 47.78 Canceled (49,086) 57.51 Balance as of December 31, 2019 496,131 82.08 Granted 823,454 96.39 Vested and released (97,188) 81.43 Canceled (103,742) 79.72 Balance as of December 31, 2020 1,118,655 92.89 Granted 873,916 123.36 Vested and released (178,030) 92.14 Canceled (315,988) 97.79 Balance as of December 31, 2021 1,498,553 $ 109.72 A summary of the Company’s performance-based restricted stock unit activity under the 2018 Plan and related information is as follows: Performance-based Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of January 1, 2020 — $ — Granted 377,922 113.40 Balance as of December 31, 2020 377,922 113.40 Granted 52,917 135.94 Canceled (56,243) 113.40 Balance as of December 31, 2021 374,596 $ 116.58 Market-based Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of January 1, 2020 — $ — Granted 3,391,148 67.00 Balance as of December 31, 2020 3,391,148 67.00 Vested and released (572,130) 70.58 Canceled (1) (558,254) 70.58 Balance as of December 31, 2021 2,260,764 $ 65.20 (1) Represented shares withheld by the Company for MSU holders' tax obligation upon release of vested MSUs.
Schedule of Performance-based Restricted Stock Unites Vesting Conditions	The following table presents additional information relating to each MSU award: Tranche Price Goal Number of RSUs Tranche 1 $120 per share 565,192 Tranche 2 $150 per share 565,191 Tranche 3 $200 per share 565,191
Schedule of Stock Based Compensation Expense	The following table presents the effect of employee and non‑employee related stock‑based compensation expense including the Joint Venture: Year Ended December 31, 2021 2020 2019 (in thousands) Cost of precision oncology testing $ 3,468 $ 1,839 $ 863 Research and development expense 18,907 10,024 5,907 Sales and marketing expense 15,479 9,279 4,716 General and administrative expense 113,595 122,971 5,468 Total stock-based compensation expense $ 151,449 $ 144,113 $ 16,954
Schedule of Stock Options Valuation Assumptions	The grant date fair value of stock options was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions including the Joint Venture: Year Ended December 31, 2021 2020 2019 Expected term (in years) 5.49 – 6.06 5.50 – 6.10 5.50 – 6.22 Expected volatility 63.6% – 66.7% 63.6% – 73.3% 63.2% – 68.7% Risk-free interest rate 0.3% – 1.3% 0.3% – 1.6% 1.6% – 2.7% Expected dividend yield —% —% —%
Schedule of Employee Stock Purchase Plan Valuation Assumptions	The grant date fair value of the stock purchase right granted under the ESPP was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2021 2020 2019 Expected term (in years) 0.50 0.50 0.29 – 0.50 Expected volatility 46.5% – 50.8% 45.7% – 73.2% 58.8% – 60.3% Risk-free interest rate —% – 0.1% 0.1% – 0.2% 1.6% – 2.5% Expected dividend yield —% —% —%

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of the basic and diluted net loss per share attributable to Guardant Health, Inc. common stockholders: Year Ended December 31, 2021 2020 2019 (in thousands, except per share data) Net loss $ (384,770) $ (246,283) $ (67,851) Adjustment of redeemable noncontrolling interest (20,900) (7,500) (7,800) Net loss attributable to Guardant Health, Inc. common stockholders, basic and diluted $ (405,670) $ (253,783) $ (75,651) Net loss per share attributable to Guardant Health, Inc. common stockholders, basic and diluted $ (4.00) $ (2.60) $ (0.84) Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, basic and diluted 101,314 97,504 90,597
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share attributable to Guardant Health, Inc. common stockholders for the periods presented as they had an anti-dilutive effect: Year Ended December 31, 2021 2020 2019 (in thousands) Stock options issued and outstanding (1) 2,715 3,830 5,976 Restricted stock units 1,208 687 252 MSUs 2,357 2,031 — PSUs 397 60 — ESPP obligation 45 37 52 Common stock subject to repurchase 7 18 31 Convertible senior notes 8,225 961 — Total 14,954 7,624 6,311

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of components of loss before provision for income taxes	The components of loss before provision for income taxes were as follows (in thousands): Year Ended December 31, 2021 2020 2019 (in thousands) United States $ (384,976) $ (246,463) $ (69,930) Foreign 506 559 207 Total (384,470) (245,904) (69,723)
Schedule of components of the provision for income taxes	The components of the provision for income taxes are as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Current: State $ 4 $ 5 $ 3 Foreign 118 242 266 Total current tax expense $ 122 $ 247 $ 269 Deferred: Federal $ 108 $ 184 $ (1,652) State 20 34 (311) Foreign 50 (86) (178) Total deferred tax expense $ 178 $ 132 $ (2,141) Total provision for income taxes $ 300 $ 379 $ (1,872)
Schedule of the components of deferred tax assets and liabilities	Significant components of the Company’s deferred tax assets are as follows: As of December 31, 2021 2020 (in thousands) Deferred tax assets: Net operating losses carryforwards $ 232,657 $ 133,015 Property, equipment and intangible assets 13,233 14,198 Accruals and reserves 10,326 10,117 Research and development credits 33,977 19,022 Stock-based compensation 10,217 28,745 Lease liabilities 59,465 12,092 Other 948 65 Total deferred tax asset $ 360,823 $ 217,254 Deferred tax liabilities: Section 481 (a) adjustment (305) (607) Right-of-use asset (47,130) (9,383) Unrealized gain/loss on investments — (571) Debt discount — (81,964) Other (14) — Total deferred tax liabilities (47,449) (92,525) Less: valuation allowance (313,125) (124,433) Net deferred tax assets $ 249 $ 296
Effective tax rate reconciliation	The following table presents a reconciliation of the income tax expense computed at the statutory federal rate and the Company’s income tax expense for the periods presented: Year Ended December 31, 2021 2020 2019 (in thousands) Tax at the statutory federal rate $ (80,739) $ (51,639) $ (14,642) Other nondeductible items 1,399 786 887 Stock-based compensation 1,354 (13,382) (33,042) Research and development credits (14,956) (7,890) (5,266) Change in valuation allowance 106,227 81,395 59,049 State taxes, net of federal benefits (14,998) (11,119) (8,253) Other 2,013 2,228 (605) Total provision for (benefit from) income taxes $ 300 $ 379 $ (1,872)
Reconciliation of the balance of total gross unrecognized tax benefits	A reconciliation of the beginning and ending balance of total unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Unrecognized tax benefits - Beginning of period $ 11,269 $ 6,543 $ 3,427 Increases related to current year’s tax positions 8,223 4,666 3,116 Increases related to prior years’ tax positions 608 60 — Unrecognized tax benefits - End of period $ 20,100 $ 11,269 $ 6,543

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table sets forth the Company’s revenue by geographic areas based on the customers’ locations: Year Ended December 31, 2021 2020 2019 (in thousands) United States $ 352,561 $ 264,657 $ 194,312 International (1) 21,092 22,073 20,063 Total revenue $ 373,653 $ 286,730 $ 214,375

Description of Business (Detail

Description of Business (Details)	May 31, 2018
Guardant Health AMEA, Inc
Subsidiary, Sale of Stock [Line Items]
Equity method investment, ownership percentage	50.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Aug. 31, 2020USD ($)	Dec. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of operating segments | segment				1
Number of reportable segments | segment				1
Restricted cash – included in other assets, net	$ 100			$ 100
Restricted cash		$ 0			$ 0
Non-marketable equity and other investments	39,400	0		39,400	0
Impairment or adjustments of non-marketable securities				0
Other receivables and other assets due from a third-party			$ 8,000
Other receivables and other assets, term			6 years
Contractual receivables, installment payment	1,100	1,000
Contractual receivables, credit loss	5,900			0
Contract assets	5,700	1,400		5,700	1,400
Goodwill impairment	0			0
Revenue from cash collections exceeding estimated variable consideration				19,300	26,000	$ 16,800
Deferred revenue	$ 11,300	8,600		11,300	8,600
Deferred revenue, revenue recognized				8,300	10,200
Advertising expense				$ 2,400	1,200	$ 1,300
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Remaining performance obligation, expected recognition period	12 months			12 months
Collaborative Arrangement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 3,500	$ 3,000		$ 3,500	3,000
Deferred revenue, revenue recognized				$ 3,000	$ 4,800
Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Intangible assets, useful life				6 years
Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Intangible assets, useful life				12 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Concentration Risk (Details) - Credit Concentration Risk	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Customer A | Revenue
Concentration Risk [Line Items]
Concentration risk, percentage		10.00%	26.00%
Customer A | Accounts Receivable, Net
Concentration Risk [Line Items]
Concentration risk, percentage		11.00%
Customer B | Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	29.00%	25.00%	14.00%
Customer B | Accounts Receivable, Net
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	13.00%
Customer C | Accounts Receivable, Net
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%	12.00%
Customer D | Accounts Receivable, Net
Concentration Risk [Line Items]
Concentration risk, percentage		11.00%
Customer E | Accounts Receivable, Net
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Receivable and Related Credit Loss (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Financing receivable, gross amount, current	$ 0	$ 0	$ 0
Financing receivable, net amount, noncurrent	5,900	5,900	7,000
Allowance for Credit Losses
Beginning balance, financing receivable, allowance for credit loss, current		0
Additions: charged to other income (expense), net, allowance for credit loss, current		1,100
Reclassification, allowance for credit loss, current		(1,100)
Ending balance, financing receivable, allowance for credit loss, current	0	0
Beginning balance, financing receivable, allowance for credit loss, noncurrent		(7,000)
Contractual receivables, credit loss	5,900	0
Reclassification, allowance for credit loss, noncurrent		1,100
Ending balance, financing receivable, allowance for credit loss, noncurrent	(5,900)	(5,900)
Financing receivable, net amount, current	0	0	0
Financing receivable, net amount, noncurrent	$ 0	$ 0	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Useful Life of Property and Equipment, Net (Details)	12 Months Ended
	Dec. 31, 2021
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Computer hardware and computer software
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years

Investment in Joint Venture (De

Investment in Joint Venture (Details) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
		Jun. 30, 2020$ / sharesshares	May 31, 2018USD ($)seatvoteshares	Dec. 31, 2021USD ($)shares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)
Schedule of Equity Method Investments [Line Items]
Common stock, shares authorized (in shares)				350,000,000	350,000,000
Preferred stock, shares authorized (in shares)				10,000,000	10,000,000
Preferred stock, shares issued (in shares)				0	0
Common stock, shares reserved for future issuance (in shares)				13,416,775	11,344,620
Common stock, shares issued (in shares)				101,767,446	100,213,985
Common stock, shares outstanding (in shares)				101,767,446	100,213,985
Preferred stock, shares outstanding (in shares)				0	0
Variable interest entity, assets | $	[1]			$ 2,204,499	$ 2,271,781
Noncontrolling interest liability | $				78,000	0	$ 0
VIE, primary beneficiary
Schedule of Equity Method Investments [Line Items]
Variable interest entity, assets | $				$ 20,400	$ 35,000
SoftBank
Schedule of Equity Method Investments [Line Items]
Threshold percentage of fair value that is no less than internal rate of return				20.00%
Variable interest entity, threshold of capital invested by softbank | $				$ 41,000
Noncontrolling interest liability | $				$ 78,000
Guardant Health AMEA, Inc
Schedule of Equity Method Investments [Line Items]
Payments to acquire interest in joint venture | $			$ 9,000
Equity method investment, shares purchased (in shares)			40,000
Equity method investment, ownership percentage			50.00%
Number of seats on the board | seat			2
Number of votes for any board resolution | vote			1
Common stock, shares authorized (in shares)		89,000,000
Threshold period for unremedied material breach of the joint venture agreement by the other party				20 days
Guardant Health AMEA, Inc | Common Class A
Schedule of Equity Method Investments [Line Items]
Common stock, shares authorized (in shares)		80,000,000
Common stock, shares issued (in shares)				0	0
Common stock, shares outstanding (in shares)				0	0
Guardant Health AMEA, Inc | Common Class B
Schedule of Equity Method Investments [Line Items]
Common stock, shares authorized (in shares)		9,000,000
Common stock, shares issued (in shares)				602,408	0
Common stock, shares outstanding (in shares)				602,408	0
Guardant Health AMEA, Inc | Common Class B | AMEA 2020 Plan
Schedule of Equity Method Investments [Line Items]
Common stock, shares reserved for future issuance (in shares)		4,595,555		4,595,555
Guardant Health AMEA, Inc | Series A Preferred Stock
Schedule of Equity Method Investments [Line Items]
Preferred stock, shares authorized (in shares)		80,000,000
Dividend rate (in usd per share) | $ / shares		$ 0.05
Preferred stock, shares outstanding (in shares)				80,000,000	80,000,000
Guardant Health AMEA, Inc | Series A Preferred Stock | Guardant Health, Inc.
Schedule of Equity Method Investments [Line Items]
Preferred stock, shares issued (in shares)		40,000,000
Guardant Health AMEA, Inc | SoftBank
Schedule of Equity Method Investments [Line Items]
Payments to acquire interest in joint venture | $			$ 41,000
Equity method investment, shares purchased (in shares)			40,000
Equity method investment, ownership percentage			50.00%
Redeemable noncontrolling interest, redemption value | $			$ 41,000
Guardant Health AMEA, Inc | SoftBank | Series A Preferred Stock
Schedule of Equity Method Investments [Line Items]
Preferred stock, shares issued upon conversion of stock (in shares)		1,000
[1]	As of December 31, 2021 and 2020, this balance includes $20.4 million and $35.0 million of assets, respectively, that can be used only to settle obligations of the consolidated variable interest entity, or VIE, and VIE’s subsidiaries, and $4.3 million and $4.9 million of liabilities of the consolidated VIE and VIE’s subsidiaries, respectively, for which their creditors do not have recourse to the general credit of the Company. See Note 3, Investment in Joint Venture.

Consolidated Balance Sheet Co_3

Consolidated Balance Sheet Components - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 179,285	$ 97,127
Less: accumulated depreciation	(54,824)	(34,345)
Property and equipment, net	124,461	62,782
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	63,022	40,216
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	38,702	34,037
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment, gross	16,685	10,862
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	55,873	7,833
Construction in progress | Office In Palo Alto, California
Property, Plant and Equipment [Line Items]
Property and equipment, gross	45,800	1,100
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,683	3,043
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,320	$ 1,136

Consolidated Balance Sheet Co_4

Consolidated Balance Sheet Components - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense	$ 20.2	$ 14.1	$ 9.3

Consolidated Balance Sheet Co_5

Consolidated Balance Sheet Components - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Total accrued expenses	Total accrued expenses
Operating lease liabilities	$ 12,856	$ 6,632
Accrued tax liabilities	4,223	4,634
Accrued professional services	6,994	3,397
Accrued clinical studies	3,332	1,264
Accrued legal expenses	4,166	2,875
Purchases of property and equipment included in accrued expenses	5,893	1,156
Others	7,821	2,681
Total accrued expenses	$ 45,285	$ 22,639

Fair Value Measurements. Cash_3

Fair Value Measurements. Cash Equivalents and Marketable Securities - Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 0	$ 0	$ 1,065
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	357,785	620,630
Marketable securities, short-term	440,546	961,902
Marketable securities, long-term	698,034	246,597
Total assets	1,496,365	1,829,129
Contingent consideration	3,625	1,245
Total liabilities	3,625	1,245
Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	357,785	620,630
Marketable securities, short-term	0	0
Marketable securities, long-term	0	0
Total assets	357,785	620,630
Contingent consideration	0	0
Total liabilities	0	0
Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Marketable securities, short-term	440,546	961,902
Marketable securities, long-term	698,034	246,597
Total assets	1,138,580	1,208,499
Contingent consideration	0	0
Total liabilities	0	0
Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Marketable securities, short-term	0	0
Marketable securities, long-term	0	0
Total assets	0	0
Contingent consideration	3,625	1,245
Total liabilities	3,625	1,245
U.S. government debt securities | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, short-term	440,546	961,902
Marketable securities, long-term	698,034	246,597
U.S. government debt securities | Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, short-term	0	0
Marketable securities, long-term	0	0
U.S. government debt securities | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, short-term	440,546	961,902
Marketable securities, long-term	698,034	246,597
U.S. government debt securities | Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, short-term	0	0
Marketable securities, long-term	0	0
Money market funds | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	357,785	620,630
Money market funds | Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	357,785	620,630
Money market funds | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Money market funds | Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 0	$ 0

Fair Value Measurements. Cash_4

Fair Value Measurements. Cash Equivalents and Marketable Securities - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Initial fair value of contingent consideration at acquisition date	$ 0	$ 0	$ 1,065
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long term maturity period (years)	1 year 1 month 6 days
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long term maturity period (years)	1 year 9 months 18 days
SoftBank
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Threshold percentage of fair value that is no less than internal rate of return	20.00%
Variable interest entity, threshold of capital invested by softbank	$ 41,000
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Initial fair value of contingent consideration at acquisition date	3,625	1,245
Level 3 | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Initial fair value of contingent consideration at acquisition date	$ 3,625	$ 1,245

Fair Value Measurements. Cash_5

Fair Value Measurements. Cash Equivalents and Marketable Securities - Activity in Level 3 Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial valuation on the date of acquisition	$ 0	$ 0	$ 1,065
Fair value, measurements, recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial valuation on the date of acquisition	3,625	1,245
Level 3 | Fair value, measurements, recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial valuation on the date of acquisition	3,625	1,245
Level 3 | Fair value, measurements, recurring | Contingent Consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value — beginning of period	1,245	1,365	0
Initial valuation on the date of acquisition	0	0	1,065
Increase (decrease) in fair value	2,380	(120)	300
Fair value — end of period	3,625	1,245	1,365
Level 3 | Fair value, measurements, recurring | Noncontrolling Interest Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value — beginning of period	0
Increase (decrease) in fair value	0
Net loss for the period	0
Reclassification of redeemable noncontrolling interest to noncontrolling interest liability	78,000
Fair value — end of period	78,000	0
Level 3 | Fair value, measurements, recurring | Redeemable Noncontrolling Interest
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value — beginning of period	57,100	49,600	41,800
Increase (decrease) in fair value	27,244	12,934	11,659
Net loss for the period	(6,344)	(5,434)	(3,859)
Reclassification of redeemable noncontrolling interest to noncontrolling interest liability	(78,000)	0	0
Fair value — end of period	$ 0	$ 57,100	$ 49,600

Fair Value Measurements. Cash_6

Fair Value Measurements. Cash Equivalents and Marketable Securities - Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	$ 492,202	$ 832,977
Amortized cost, cash and cash equivalents and marketable securities available-for-sale	1,499,957	1,826,825
Gross Unrealized Gain	2	2,339
Gross Unrealized Loss	(3,594)	(35)
Estimated fair value, cash, cash equivalents and marketable securities	1,496,365	1,829,129
Money market funds
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	357,785	620,630
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Estimated fair value, cash and cash equivalents	357,785	620,630
U.S. government debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost, marketable securities, available-for-sale	1,142,172	1,206,195
Gross Unrealized Gain	2	2,339
Gross Unrealized Loss	(3,594)	(35)
Estimated fair value, debt securities	$ 1,138,580	$ 1,208,499

Patent License Acquisition (Det

Patent License Acquisition (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Intangible assets subject to amortization		$ 16,986	$ 16,986
Charge of in-process research and development costs with no alternative future use		$ 0	$ 8,500	$ 0
Minimum
Business Acquisition [Line Items]
Intangible assets, useful life		6 years
Maximum
Business Acquisition [Line Items]
Intangible assets, useful life		12 years
Patent and Covenant Rights | Minimum
Business Acquisition [Line Items]
Intangible assets, useful life	6 years
Patent and Covenant Rights | Maximum
Business Acquisition [Line Items]
Intangible assets, useful life	12 years
KeyGene Patent License Acquisition
Business Acquisition [Line Items]
Payment in connection with a license agreement	$ 18,500
Asset acquisition, transaction costs	600
Charge of in-process research and development costs with no alternative future use	8,500
Litigation settlement, expense	1,200
KeyGene Patent License Acquisition | Patent and Covenant Rights
Business Acquisition [Line Items]
Intangible assets subject to amortization	$ 9,400

Intangible Assets, Net and Go_3

Intangible Assets, Net and Goodwill - Schedule of Intangible Assets by Class (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 16,986	$ 16,986
Intangible assets subject to amortization, gross carrying amount	(4,379)	(2,431)
Total	12,607	14,555
Goodwill	3,290	3,290
Gross Carrying Amount	21,876	21,876
Net Carrying Amount	17,497	19,445
IPR&D
Finite-Lived Intangible Assets [Line Items]
IPR&D	1,600	1,600
Acquired license
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	11,886	11,886
Intangible assets subject to amortization, gross carrying amount	(2,473)	(1,367)
Total	$ 9,413	$ 10,519
Remaining Weighted-Average Useful Life	8 years 9 months 18 days	9 years 9 months 18 days
Non-compete agreements and other covenant rights
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 5,100	$ 5,100
Intangible assets subject to amortization, gross carrying amount	(1,906)	(1,064)
Total	$ 3,194	$ 4,036
Remaining Weighted-Average Useful Life	3 years 10 months 24 days	4 years 10 months 24 days

Intangible Assets, Net and Go_4

Intangible Assets, Net and Goodwill - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 1.9	$ 1.8	$ 0.7

Intangible Assets, Net and Go_5

Intangible Assets, Net and Goodwill - Schedule of Future Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 1,947
2023	1,947
2024	1,953
2025	1,670
2026	1,212
2027 and thereafter	3,878
Total	$ 12,607	$ 14,555

Debt - Narrative (Details)

Debt - Narrative (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 2020USD ($)d$ / shares	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Nov. 16, 2020$ / shares
Debt Instrument [Line Items]
Notes Hedges, strike price (in dollars per share) | $ / shares				$ 182.60
Share price, premium				75.00%
Common stock share price (in dollars per share) | $ / shares				$ 104.34
Purchase of convertible senior note hedges | $		$ 90,000,000	$ 90,045,000
Senior Notes Due 2027 | Conversion Period Three
Debt Instrument [Line Items]
Threshold percentage of common stock price trigger	130.00%
Threshold of common stock trading days	20
Threshold of consecutive common stock trading days	30
Senior Notes Due 2027 | Convertible Debt
Debt Instrument [Line Items]
Principal amount | $	$ 1,150,000,000	1,150,000,000	1,150,000,000
Stated interest rate	0.00%
Maximum special interest rate percentage	0.50%
Conversion ratio	0.0071523
Conversion price (in dollars per share) | $ / shares	$ 139.82
Estimated fair value | $		$ 1,200,000,000	$ 1,300,000,000
Senior Notes Due 2027 | Convertible Debt | Measurement Input, Quoted Price | Valuation, Market Approach
Debt Instrument [Line Items]
Debt, measurement input | $		100
Senior Notes Due 2027 | Convertible Debt | Conversion Period One
Debt Instrument [Line Items]
Threshold percentage of common stock price trigger	130.00%
Threshold of common stock trading days	20
Threshold of consecutive common stock trading days	30
Senior Notes Due 2027 | Convertible Debt | Conversion Period Two
Debt Instrument [Line Items]
Threshold of common stock trading days	5
Threshold of consecutive common stock trading days	10
Minimum percentage of common stock price trigger	98.00%

Debt - Components of Convertibl

Debt - Components of Convertible Senior Notes (Details) - Convertible Debt - Senior Notes Due 2027 - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Nov. 30, 2020
Debt Instrument [Line Items]
Principal	$ 1,150,000	$ 1,150,000	$ 1,150,000
Less: debt discount, net of amortization	0	(331,074)
Less: debt issuance costs, net of amortization	(15,179)	(12,634)
Net carrying amount	1,134,821	806,292
2027 Notes	0	335,667
Less: issuance costs	0	(5,264)
Net amount recorded in equity	$ 0	$ 330,403

Debt - Interest Expense Recogni

Debt - Interest Expense Recognition (Details) - Convertible senior notes - Senior Notes Due 2027 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Amortization of debt discount	$ 0	$ 4,593
Amortization of debt issuance costs	2,564	136
Total interest expense recognized	$ 2,564	$ 4,729
Effective interest rate of the liability component	0.20%	5.20%

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2020segment	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease expense | $		$ 24.7	$ 5.6	$ 4.4
Office and laboratory space
Lessee, Lease, Description [Line Items]
Number of lease agreements, not yet commenced | segment	2
Renewal lease term, lease not yet commenced	10 years
Office and laboratory space | San Diego, California
Lessee, Lease, Description [Line Items]
Lease not yet commenced, term	8 years
Office and laboratory space | Palo Alto, California
Lessee, Lease, Description [Line Items]
Lease not yet commenced, term	12 years
Minimum
Lessee, Lease, Description [Line Items]
Lease term		1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease term		12 years

Leases - Lease Information (Det

Leases - Lease Information (Details)	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Weighted-average remaining lease term (in years)	10 years	5 years 6 months
Weighted-average discount rate	4.01%	8.07%

Leases - Schedule of Operating

Leases - Schedule of Operating Liability Maturities (Details) $ in Thousands	Dec. 31, 2021USD ($)
Leases [Abstract]
2022	$ 18,840
2023	29,056
2024	31,584
2025	32,063
2026	27,753
2027 and thereafter	149,637
Total operating lease payments	288,933
Less: Imputed Interest	(50,024)
Total operating lease liabilities	$ 238,909

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Dec. 10, 2020patent	Oct. 31, 2021patent	May 31, 2021USD ($)	Mar. 31, 2021patent	Nov. 30, 2020patent	Jul. 31, 2018petitionpatent	Nov. 30, 2017patent	Dec. 31, 2021USD ($)party	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Other Commitments [Line Items]
Number of parties with patent license agreement | party								4
Royalty expense | $								$ 0.7	$ 1.1	$ 4.4
Percentage of precision oncology testing revenue								0.20%	0.40%	2.00%
Gain contingency, patents allegedly infringed upon, number							4
Foundation Medicine, Inc. vs. Guardant Health, Inc..
Other Commitments [Line Items]
Royalty expense | $			$ 25
Gain contingency, patents allegedly infringed upon, number	2			2	7	4
Number of petitions filed | petition						6
Number of remaining petitions | petition						2
TwinStrand Biosciences And University Of Washington vs. Guardant Health, Inc.
Other Commitments [Line Items]
Gain contingency, patents allegedly infringed upon, number		4

Common Stock (Details)

Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2020	May 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Dividends			$ 0	$ 0
Common stock, shares reserved for future issuance (in shares)			13,416,775	11,344,620
Issuance of common stock upon follow-on offering, net of offering costs (in shares)	4,312,500	5,175,000
Share price of stock issued (in usd per share)	$ 84	$ 71
Issuance of common stock upon follow-on offering, net of offering costs	$ 354,600	$ 349,700		$ 354,600	$ 349,709
Shares underlying outstanding stock options
Class of Stock [Line Items]
Common stock, shares reserved for future issuance (in shares)			2,624,974	3,101,181
Shares underlying unvested restricted stock units
Class of Stock [Line Items]
Common stock, shares reserved for future issuance (in shares)			1,498,553	1,118,655
Market-based restricted stock units
Class of Stock [Line Items]
Common stock, shares reserved for future issuance (in shares)			2,260,764	3,391,148
Performance-based restricted stock units
Class of Stock [Line Items]
Common stock, shares reserved for future issuance (in shares)			374,596	377,922
Shares available for issuance under the 2018 Incentive Award Plan
Class of Stock [Line Items]
Common stock, shares reserved for future issuance (in shares)			5,231,624	1,819,223
Shares available for issuance under the 2018 Employee Stock Purchase Plan
Class of Stock [Line Items]
Common stock, shares reserved for future issuance (in shares)			1,426,264	1,536,491

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands	May 26, 2020	Jan. 01, 2020shares	Dec. 31, 2020USD ($)shares	Nov. 30, 2020	May 31, 2020	May 31, 2020shares	May 31, 2020segment	Dec. 31, 2019USD ($)	Oct. 31, 2018shares	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Jun. 30, 2020shares	Sep. 30, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants in period (in usd per share) | $ / shares										$ 70.25	$ 48.99	$ 52.37
Stock based compensation not recognized | $										$ 31,700
Stock based compensation not recognized, period for recognition (years)										3 years
Reversal of stock based compensation expense | $			$ 700					$ 1,000
Share-based compensation expense | $										$ 151,449	$ 144,113	$ 16,954
Common stock, shares reserved for future issuance (in shares) | shares			11,344,620							13,416,775	11,344,620
Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercises in period, intrinsic value | $										$ 83,500	$ 120,000	$ 218,200
Common stock, shares reserved for future issuance (in shares) | shares			3,101,181							2,624,974	3,101,181
Expected dividend yield										0.00%	0.00%	0.00%
Stock option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility										63.60%	63.60%	63.20%
Risk-free interest rate										0.30%	0.30%	1.60%
Stock option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility										66.70%	73.30%	68.70%
Risk-free interest rate										1.30%	1.60%	2.70%
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation not recognized, period for recognition (years)										3 years 1 month 6 days
Stock based compensation not recognized, restricted stock | $										$ 142,800
Weighted-average grant date fair value, granted (in usd per share) | $ / shares										$ 123.36	$ 96.39	$ 78.61
Common stock, shares reserved for future issuance (in shares) | shares			1,118,655							1,498,553	1,118,655
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation not recognized, period for recognition (years)										3 years 1 month 6 days
Stock based compensation not recognized, restricted stock | $										$ 3,900
Service period				4 years
Additional service period				6 months
Share-based compensation expense | $										$ 1,300	$ 100
Weighted-average grant date fair value, granted (in usd per share) | $ / shares										$ 135.94	$ 113.40
Common stock, shares reserved for future issuance (in shares) | shares			377,922							374,596	377,922
PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years 6 months
MSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation not recognized, period for recognition (years)										6 months
Stock based compensation not recognized, restricted stock | $										$ 16,100
Vesting period	7 years				7 years
Share-based compensation expense | $										$ 99,200	$ 111,900
Market-based restricted stock share price goal					30 days
Weighted-average grant date fair value, granted (in usd per share) | $ / shares										$ 67	$ 67
Common stock, shares reserved for future issuance (in shares) | shares			3,391,148							2,260,764	3,391,148
Expected dividend yield										0.00%
Expected volatility										65.50%
Risk-free interest rate										0.53%
Risky rate, cost of equity										0.16
MSUs | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of tranches						1,695,574	3
MSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period										9 months 29 days
Market-based stock units holding period during vesting					6 months
Discount for post-vesting restrictions										10.40%
MSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period										2 years 25 days
Market-based stock units holding period during vesting					12 months
Discount for post-vesting restrictions										14.50%
ESPP obligation
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation not recognized, period for recognition (years)										4 months 24 days
Stock based compensation not recognized, restricted stock | $										$ 1,600
Share-based compensation expense | $										$ 3,500	$ 3,000	$ 2,300
Employee stock purchase plan, purchase price of common stock										85.00%
Common stock, shares reserved for future issuance (in shares) | shares			1,536,491							1,426,264	1,536,491
Expected dividend yield										0.00%	0.00%	0.00%
Shares authorized (in shares) | shares		942,614
Employee stock purchase plan, maximum employee subscription rate										10.00%
Purchase period										6 months
Common stock issued under employee stock purchase plan (in shares) | shares										110,227	96,040	232,333
ESPP obligation | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility										46.50%	45.70%	58.80%
Risk-free interest rate										0.00%	0.10%	1.60%
ESPP obligation | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility										50.80%	73.20%	60.30%
Risk-free interest rate										0.10%	0.20%	2.50%
2012 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares canceled (in shares) | shares									508,847
AMEA 2020 Plan | Common Class B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants in period (in usd per share) | $ / shares										$ 0.33	$ 0.33
Stock based compensation not recognized | $										$ 400
Stock based compensation not recognized, period for recognition (years)										2 years 6 months
Shares authorized (in shares) | shares											4,595,555
AMEA 2020 Plan | Guardant Health AMEA, Inc | Common Class B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares reserved for future issuance (in shares) | shares										4,595,555			4,595,555
AMEA 2020 Plan | Guardant Health AMEA, Inc | Tranche One | Common Class B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period										4 years
Option term, expiration period										10 years
AMEA 2020 Plan | Guardant Health AMEA, Inc | Tranche Two | Common Class B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option term, expiration period										5 years
Threshold percentage for individual's combined voting power triggering five year option term										10.00%
Employee stock purchase plan, purchase price of common stock										110.00%
2018 Employee Stock Purchase Plan | ESPP obligation
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares reserved for future issuance (in shares) | shares														922,250

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shares Available for Grant
Beginning number of shares, available for grant (in shares)	1,819,223	2,726,225	3,556,507
2018 plan annual increase (in shares)	3,689,000	3,689,000
Ending number of shares, available for grant (in shares)	5,231,624	1,819,223	2,726,225	3,556,507
Shares Subject to Options Outstanding
Beginning number of shares, outstanding (in shares)	3,101,181	4,494,889	7,588,405
Granted (in shares)	345,774	127,590	324,579
Exercised (in shares)	(693,074)	(1,446,843)	(2,999,419)
Canceled (in shares)	(128,907)	(74,455)	(418,676)
Ending number of shares, outstanding (in shares)	2,624,974	3,101,181	4,494,889	7,588,405
Options vested and exercisable, number of options (in shares)	1,973,789
Weighted-Average Exercise Price
Beginning balance of options outstanding (in usd per share)	$ 15.80	$ 10.90	$ 4.58
Granted (in usd per share)	119.82	81.78	88.18
Exercised (in usd per share)	11.19	6.59	3.87
Canceled (in usd per share)	47.51	12.13	6.64
Ending balance of options outstanding (in usd per share)	29.17	$ 15.80	$ 10.90	$ 4.58
Options vested and exercisable, weighted average exercise price per share (in usd per share)	$ 11.05
Weighted-Average Remaining Contractual Life and Aggregate Intrinsic Value
Options outstanding, weighted average remaining contractual term (in years)	6 years 6 months	6 years 10 months 24 days	7 years 8 months 12 days	8 years 3 months 18 days
Options outstanding, aggregate intrinsic value	$ 193,014	$ 350,670	$ 306,392	$ 250,495
Options vested and exercisable, weighted average remaining contractual term (in years)	5 years 9 months 18 days
Options vested and exercisable, aggregate intrinsic value	$ 175,783
Equity Option
Shares Available for Grant
Granted (in shares)	(345,774)	(127,590)	(324,579)
Canceled (in shares)	65,523	20,370	12,636
Restricted Stock Units
Shares Available for Grant
Granted (in shares)	(873,916)	(823,454)	(567,425)
Canceled (in shares)	315,988	103,742	49,086
Market-based restricted stock units
Shares Available for Grant
Granted (in shares)	0	(3,391,148)
Canceled (in shares)	558,254
PSUs
Shares Available for Grant
Granted (in shares)	(52,917)	(377,922)
Canceled (in shares)	56,243

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restricted stock units
Awards Outstanding
Beginning unvested balance (in shares)	1,118,655	496,131	0
Granted (in shares)	873,916	823,454	567,425
Vested and released (in shares)	(178,030)	(97,188)	(22,208)
Canceled (in shares)	(315,988)	(103,742)	(49,086)
Ending unvested balance (in shares)	1,498,553	1,118,655	496,131
Weighted-Average Grant Date Fair Value
Beginning balance of options outstanding (in usd per share)	$ 92.89	$ 82.08	$ 0
Granted (in usd per share)	123.36	96.39	78.61
Vested and released (in usd per share)	92.14	81.43	47.78
Canceled (in usd per share)	97.79	79.72	57.51
Ending balance of options outstanding (in usd per share)	$ 109.72	$ 92.89	$ 82.08
PSUs
Awards Outstanding
Beginning unvested balance (in shares)	377,922	0
Granted (in shares)	52,917	377,922
Canceled (in shares)	(56,243)
Ending unvested balance (in shares)	374,596	377,922	0
Weighted-Average Grant Date Fair Value
Beginning balance of options outstanding (in usd per share)	$ 113.40	$ 0
Granted (in usd per share)	135.94	113.40
Canceled (in usd per share)	113.40
Ending balance of options outstanding (in usd per share)	$ 116.58	$ 113.40	$ 0
MSUs
Awards Outstanding
Beginning unvested balance (in shares)	3,391,148	0
Granted (in shares)		3,391,148
Vested and released (in shares)	(572,130)
Canceled (in shares)	(558,254)
Ending unvested balance (in shares)	2,260,764	3,391,148	0
Weighted-Average Grant Date Fair Value
Beginning balance of options outstanding (in usd per share)	$ 67	$ 0
Granted (in usd per share)	67	67
Vested and released (in usd per share)	70.58
Canceled (in usd per share)	70.58
Ending balance of options outstanding (in usd per share)	$ 65.20	$ 67	$ 0

Stock-Based Compensation - Mark

Stock-Based Compensation - Market-based Restricted Stock Units (Details) - MSUs	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Tranche 1 - $120 per share
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price goal (in dollars per share) | $ / shares	$ 120
Number of MSUs (in shares) | shares	565,192
Tranche 2 - $150 per share
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price goal (in dollars per share) | $ / shares	$ 150
Number of MSUs (in shares) | shares	565,191
Tranche 3 - $200 per share
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price goal (in dollars per share) | $ / shares	$ 200
Number of MSUs (in shares) | shares	565,191

Stock-Based Compensation - AMEA

Stock-Based Compensation - AMEA 2020 Equity Incentive Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shares Available for Grant
Beginning number of shares, available for grant (in shares)	1,819,223	2,726,225	3,556,507
Ending number of shares, available for grant (in shares)	5,231,624	1,819,223	2,726,225	3,556,507
Shares Subject to Options Outstanding
Beginning number of shares, outstanding (in shares)	3,101,181	4,494,889	7,588,405
Granted (in shares)	345,774	127,590	324,579
Exercised (in shares)	(693,074)	(1,446,843)	(2,999,419)
Canceled (in shares)	(128,907)	(74,455)	(418,676)
Ending number of shares, outstanding (in shares)	2,624,974	3,101,181	4,494,889	7,588,405
Options vested and exercisable, number of options (in shares)	1,973,789
Weighted-Average Exercise Price
Beginning balance of options outstanding (in usd per share)	$ 15.80	$ 10.90	$ 4.58
Granted (in usd per share)	119.82	81.78	88.18
Exercised (in usd per share)	11.19	6.59	3.87
Canceled (in usd per share)	47.51	12.13	6.64
Ending balance of options outstanding (in usd per share)	29.17	$ 15.80	$ 10.90	$ 4.58
Options vested and exercisable, weighted average exercise price per share (in usd per share)	$ 11.05
Weighted-Average Remaining Contractual Life and Aggregate Intrinsic Value
Options outstanding, weighted average remaining contractual term (in years)	6 years 6 months	6 years 10 months 24 days	7 years 8 months 12 days	8 years 3 months 18 days
Options outstanding, aggregate intrinsic value	$ 193,014	$ 350,670	$ 306,392	$ 250,495
Options vested and exercisable, weighted average remaining contractual term (in years)	5 years 9 months 18 days
Options vested and exercisable, aggregate intrinsic value	$ 175,783
AMEA 2020 Plan | Common Class B
Shares Available for Grant
Beginning number of shares, available for grant (in shares)	542,220	0
Shares authorized (in shares)		4,595,555
Granted (in shares)	(826,667)	(4,062,224)
Canceled (in shares)	625,375	8,889
Ending number of shares, available for grant (in shares)	340,928	542,220	0
Shares Subject to Options Outstanding
Beginning number of shares, outstanding (in shares)	4,053,335	0
Granted (in shares)	826,667	4,062,224
Exercised (in shares)	(602,408)
Canceled (in shares)	(625,375)	(8,889)
Ending number of shares, outstanding (in shares)	3,652,219	4,053,335	0
Options vested and exercisable, number of options (in shares)	2,148,474
Weighted-Average Exercise Price
Beginning balance of options outstanding (in usd per share)	$ 0.58	$ 0
Granted (in usd per share)	0.58	0.58
Exercised (in usd per share)	0.58
Canceled (in usd per share)	0.58	0
Ending balance of options outstanding (in usd per share)	0.58	$ 0.58	$ 0
Options vested and exercisable, weighted average exercise price per share (in usd per share)	$ 0.58
Weighted-Average Remaining Contractual Life and Aggregate Intrinsic Value
Options outstanding, weighted average remaining contractual term (in years)	8 years 9 months 18 days	9 years 7 months 6 days	0 years
Options outstanding, aggregate intrinsic value	$ 0	$ 0	$ 0
Options vested and exercisable, weighted average remaining contractual term (in years)	8 years 7 months 6 days
Options vested and exercisable, aggregate intrinsic value	$ 0

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 151,449	$ 144,113	$ 16,954
Cost of precision oncology testing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	3,468	1,839	863
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	18,907	10,024	5,907
Sales and marketing expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	15,479	9,279	4,716
General and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 113,595	$ 122,971	$ 5,468

Stock-Based Compensation - Valu

Stock-Based Compensation - Valuation of Stock Options (Details) - Stock option	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 5 months 26 days	5 years 6 months	5 years 6 months
Expected volatility	63.60%	63.60%	63.20%
Risk-free interest rate	0.30%	0.30%	1.60%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 21 days	6 years 1 month 6 days	6 years 2 months 19 days
Expected volatility	66.70%	73.30%	68.70%
Risk-free interest rate	1.30%	1.60%	2.70%

Stock-Based Compensation - Va_2

Stock-Based Compensation - Valuation of Employee Stock Purchase Plan (Details) - ESPP obligation	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			3 months 14 days
Expected volatility	46.50%	45.70%	58.80%
Risk-free interest rate	0.00%	0.10%	1.60%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 months	6 months
Expected volatility	50.80%	73.20%	60.30%
Risk-free interest rate	0.10%	0.20%	2.50%

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders - Schedule of Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss	$ (384,770)	$ (246,283)	$ (67,851)
Adjustment of redeemable noncontrolling interest	(20,900)	(7,500)	(7,800)
Net loss attributable to Guardant Health, Inc. common stockholders - basic	(405,670)	(253,783)	(75,651)
Net loss attributable to Guardant Health, Inc. common stockholders - diluted	$ (405,670)	$ (253,783)	$ (75,651)
Net loss per share attributable to Guardant Health, Inc. common stockholders, basic (in usd per share)	$ (4)	$ (2.60)	$ (0.84)
Net loss per share attributable to Guardant Health, Inc. common stockholders, diluted (in usd per share)	$ (4)	$ (2.60)	$ (0.84)
Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, basic (in shares)	101,314	97,504	90,597
Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, diluted (in shares)	101,314	97,504	90,597

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders - Schedule of Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	14,954,000	7,624,000	6,311,000
Stock options outstanding (in shares)	2,624,974	3,101,181	4,494,889	7,588,405
Common Class B | AMEA 2020 Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options outstanding (in shares)	3,652,219	4,053,335	0
Shares underlying outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,715,000	3,830,000	5,976,000
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,208,000	687,000	252,000
MSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,357,000	2,031,000	0
PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	397,000	60,000	0
ESPP obligation
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	45,000	37,000	52,000
Common stock subject to repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,000	18,000	31,000
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	8,225,000	961,000	0

Income Taxes - Schedule of Loss

Income Taxes - Schedule of Loss Before Components of the Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
United States	$ (384,976)	$ (246,463)	$ (69,930)
Foreign	506	559	207
Loss before provision for income taxes	$ (384,470)	$ (245,904)	$ (69,723)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of the Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current:
State	$ 4	$ 5	$ 3
Foreign	118	242	266
Total current tax expense	122	247	269
Deferred:
Federal	108	184	(1,652)
State	20	34	(311)
Foreign	50	(86)	(178)
Total deferred tax expense	178	132	(2,141)
Total provision for income taxes	$ 300	$ 379	$ (1,872)

Income Taxes - Schedule of the

Income Taxes - Schedule of the Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating losses carryforwards	$ 232,657	$ 133,015
Property, equipment and intangible assets	13,233	14,198
Accruals and reserves	10,326	10,117
Research and development credits	33,977	19,022
Stock-based compensation	10,217	28,745
Lease liabilities	59,465	12,092
Other	948	65
Total deferred tax asset	360,823	217,254
Deferred tax liabilities:
Section 481 (a) adjustment	(305)	(607)
Right-of-use asset	(47,130)	(9,383)
Unrealized gain/loss on investments	0	(571)
Debt discount	0	(81,964)
Other	(14)	0
Total deferred tax liabilities	(47,449)	(92,525)
Less: valuation allowance	(313,125)	(124,433)
Net deferred tax assets	$ 249	$ 296

Income Taxes - Effective Tax Ra

Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Tax at the statutory federal rate	$ (80,739)	$ (51,639)	$ (14,642)
Other nondeductible items	1,399	786	887
Stock-based compensation	1,354	(13,382)	(33,042)
Research and development credits	(14,956)	(7,890)	(5,266)
Change in valuation allowance	106,227	81,395	59,049
State taxes, net of federal benefits	(14,998)	(11,119)	(8,253)
Other	2,013	2,228	(605)
Total provision for income taxes	$ 300	$ 379	$ (1,872)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Release of valuation allowance	$ (188,700)	$ 800	$ (59,000)
Benefit from intraperiod tax allocation			400
Unrecognized tax benefits	20,100	11,269	6,543	$ 3,427
Unrecognized tax benefits, income tax penalties and interest accrued	0	0	0
Unrecognized tax benefits, period increase (decrease)	0
Federal
Income Taxes [Line Items]
Net operating loss carryforwards	956,900	547,300
Tax credit carryforwards, research	21,400	11,900
State
Income Taxes [Line Items]
Net operating loss carryforwards	542,000	306,700
Tax credit carryforwards, research	$ 15,900	$ 9,100
Intangible assets
Income Taxes [Line Items]
Release of valuation allowance			$ 1,600

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Balance of Total Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits - Beginning of period	$ 11,269	$ 6,543	$ 3,427
Increases related to current year’s tax positions	8,223	4,666	3,116
Increases related to prior years’ tax positions	608	60	0
Unrecognized tax benefits - End of period	$ 20,100	$ 11,269	$ 6,543

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Defined contribution plan, maximum annual employee contributions per employee, percent	100.00%
Defined contribution plan, employer contributions	$ 4.5	$ 2.8	$ 0.3

Segment and Geographic Inform_3

Segment and Geographic Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment	1
Total revenue	$ 373,653	$ 286,730	$ 214,375
United States
Segment Reporting Information [Line Items]
Total revenue	$ 352,561	$ 264,657	194,312
United States | Geographic Concentration Risk | Long-Lived Assets and Right-Of-Use Assets
Segment Reporting Information [Line Items]
Concentration risk, percentage	98.00%	94.00%
International
Segment Reporting Information [Line Items]
Total revenue	$ 21,092	$ 22,073	$ 20,063