BlackLine (BL) 10-Q 9 Nov 20 2020 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-37924
Entity Registrant Name	BlackLine, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-3354276
Entity Address, Address Line One	21300 Victory Boulevard
Entity Address, Address Line Two	12th Floor
Entity Address, City or Town	Woodland Hills
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91367
City Area Code	818
Local Phone Number	223-9008
Title of 12(b) Security	Common stock, par value $0.01 per share
Trading Symbol	BL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		57,254,972
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001666134
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 408,070	$ 120,232
Marketable securities	117,433	487,515
Accounts receivable, net of allowances for credit losses of $4,983 and $3,533 at September 30, 2020 and December 31, 2019, respectively	91,137	102,829
Prepaid expenses and other current assets	137,357	12,830
Total current assets	753,997	723,406
Capitalized software development costs, net	13,925	10,032
Property and equipment, net	10,787	13,024
Intangible assets, net	15,066	17,520
Goodwill	185,138	185,138
Operating lease right-of-use assets	9,274	12,549
Other assets	58,578	52,883
Total assets	1,046,765	1,014,552
Current liabilities:
Accounts payable	2,088	7,401
Accrued expenses and other current liabilities	29,546	30,098
Deferred revenue	165,699	162,552
Short-term portion of operating lease liabilities	4,289	4,938
Short-term portion of contingent consideration	2,008	2,008
Total current liabilities	203,630	206,997
Operating lease liabilities, noncurrent	7,828	10,606
Convertible senior notes, net	401,217	384,343
Contingent consideration	4,206	4,354
Deferred tax liabilities, net	4,750	4,571
Deferred revenue, noncurrent	72	163
Total liabilities	621,703	611,034
Commitments and contingencies (Note 7)
Redeemable non-controlling interest (Note 3)	8,128	4,905
Stockholders' equity:
Common stock	573	559
Additional paid-in capital	605,078	561,275
Accumulated other comprehensive income	568	377
Accumulated deficit	(189,285)	(163,598)
Total stockholders' equity	416,934	398,613
Total liabilities, redeemable non-controlling interest, and stockholders' equity	$ 1,046,765	$ 1,014,552

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (PARENTHETICAL) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowances for credit losses	$ 4,983	$ 3,533

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Total revenues	$ 90,157	$ 74,925	$ 256,027	$ 208,718
Cost of revenues
Total cost of revenues	16,982	15,292	49,790	43,854
Gross profit	73,175	59,633	206,237	164,864
Operating expenses
Sales and marketing	42,588	41,848	129,199	114,888
Research and development	14,829	11,558	38,423	32,694
General and administrative	17,794	14,088	51,314	40,444
Total operating expenses	75,211	67,494	218,936	188,026
Loss from operations	(2,036)	(7,861)	(12,699)	(23,162)
Other income (expense)
Interest income	648	2,161	4,142	3,590
Interest expense	(5,914)	(3,006)	(17,340)	(3,006)
Other income (expense), net	(5,266)	(845)	(13,198)	584
Loss before income taxes	(7,302)	(8,706)	(25,897)	(22,578)
Provision for income taxes	555	170	871	856
Net loss	(7,857)	(8,876)	(26,768)	(23,434)
Net loss attributable to non-controlling interest	(425)	(509)	(1,081)	(978)
Adjustment attributable to non-controlling interest	1,319	839	4,239	893
Net loss attributable to BlackLine, Inc.	$ (8,751)	$ (9,206)	$ (29,926)	$ (23,349)
Basic net loss per share attributable to BlackLine, Inc. (in usd per share)	$ (0.15)	$ (0.17)	$ (0.53)	$ (0.42)
Shares used to calculate basic net loss per share (in shares)	57,063	55,480	56,619	55,164
Diluted net loss per share attributable to BlackLine, Inc. (in usd per share)	$ (0.15)	$ (0.17)	$ (0.53)	$ (0.42)
Shares used to calculate diluted net loss per share (in shares)	57,063	55,480	56,619	55,164
Subscription and support
Revenue from Contract with Customer [Abstract]
Total revenues	$ 83,875	$ 70,311	$ 238,777	$ 197,651
Cost of revenues
Total cost of revenues	11,700	11,689	34,708	34,109
Professional services
Revenue from Contract with Customer [Abstract]
Total revenues	6,282	4,614	17,250	11,067
Cost of revenues
Total cost of revenues	$ 5,282	$ 3,603	$ 15,082	$ 9,745

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (7,857)	$ (8,876)	$ (26,768)	$ (23,434)
Other comprehensive income:
Net change in unrealized gains (losses) on marketable securities, net of tax of $0 for the quarters and nine months ended September 30, 2020 and 2019	(419)	(23)	126	213
Foreign currency translation	88	10	130	308
Other comprehensive income (loss)	(331)	(13)	256	521
Comprehensive loss	(8,188)	(8,889)	(26,512)	(22,913)
Less comprehensive loss attributable to redeemable non-controlling interest:
Net loss attributable to redeemable non-controlling interest	(425)	(509)	(1,081)	(978)
Foreign currency translation attributable to redeemable non-controlling interest	44	5	65	151
Comprehensive loss attributable to redeemable non-controlling interest	(381)	(504)	(1,016)	(827)
Comprehensive loss attributable to BlackLine, Inc.	$ (7,807)	$ (8,385)	$ (25,496)	$ (22,086)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) (PARENTHETICAL) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net change in unrealized gain on marketable securities, tax	$ 0	$ 0	$ 0	$ 0

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance (in shares) at Dec. 31, 2018		54,683
Beginning Balance at Dec. 31, 2018	$ 319,267	$ 547	$ 451,571	$ 45	$ (132,896)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		535
Stock option exercises	8,367	$ 4	8,363
Vesting of restricted stock units (in shares)		339
Vesting of restricted stock units	4	$ 4
Issuance of common stock through employee stock purchase plan (in shares)		74
Issuance of common stock through employee stock purchase plan	2,552	$ 1	2,551
Acquisition of common stock for tax withholding obligations	(3,372)		(3,372)
Stock-based compensation	24,901		24,901
Other comprehensive (loss) income	370			370
Equity component of convertible senior notes, net of issuance costs	111,230		111,230
Purchase of capped calls			(46,150)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest	(23,349)		(893)		(22,456)
Ending Balance (in shares) at Sep. 30, 2019		55,631
Ending Balance at Sep. 30, 2019	393,820	$ 556	548,201	415	(155,352)
Beginning Balance (in shares) at Jun. 30, 2019		55,307
Beginning Balance at Jun. 30, 2019	324,548	$ 553	470,681	299	(146,985)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		247
Stock option exercises	3,805	$ 2	3,803
Vesting of restricted stock units (in shares)		77
Vesting of restricted stock units	1	$ 1
Acquisition of common stock for tax withholding obligations	(784)		(784)
Stock-based compensation	10,260		10,260
Other comprehensive (loss) income	116			116
Equity component of convertible senior notes, net of issuance costs	111,230		111,230
Purchase of capped calls	(46,150)		(46,150)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest	(9,206)		(839)		(8,367)
Ending Balance (in shares) at Sep. 30, 2019		55,631
Ending Balance at Sep. 30, 2019	393,820	$ 556	548,201	415	(155,352)
Beginning Balance (in shares) at Dec. 31, 2019		55,931
Beginning Balance at Dec. 31, 2019	398,613	$ 559	561,275	377	(163,598)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		789
Stock option exercises	14,283	$ 9	14,274
Vesting of restricted stock units (in shares)		450
Vesting of restricted stock units	4	$ 4
Issuance of common stock through employee stock purchase plan (in shares)		85
Issuance of common stock through employee stock purchase plan	3,608	$ 1	3,607
Acquisition of common stock for tax withholding obligations	(6,128)		(6,128)
Stock-based compensation	36,289		36,289
Other comprehensive (loss) income	191			191
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest	(29,926)		(4,239)		(25,687)
Ending Balance (in shares) at Sep. 30, 2020		57,255
Ending Balance at Sep. 30, 2020	416,934	$ 573	605,078	568	(189,285)
Beginning Balance (in shares) at Jun. 30, 2020		56,855
Beginning Balance at Jun. 30, 2020	409,778	$ 569	590,119	943	(181,853)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)		296
Stock option exercises	3,870	$ 3	3,867
Vesting of restricted stock units (in shares)		104
Vesting of restricted stock units	1	$ 1
Acquisition of common stock for tax withholding obligations	(1,272)		(1,272)
Stock-based compensation	13,683		13,683
Other comprehensive (loss) income	(375)			(375)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest	(8,751)		(1,319)		(7,432)
Ending Balance (in shares) at Sep. 30, 2020		57,255
Ending Balance at Sep. 30, 2020	$ 416,934	$ 573	$ 605,078	$ 568	$ (189,285)

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net loss attributable to BlackLine, Inc.	$ (29,926)	$ (23,349)
Net loss and adjustment attributable to redeemable non-controlling interest (Note 3)	3,158	(85)
Net loss	(26,768)	(23,434)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	14,615	16,803
Change in fair value of contingent consideration	(148)	313
Amortization of debt discount and issuance costs	16,874	2,923
Stock-based compensation	35,398	24,605
Noncash lease expense	3,557	3,677
Accretion of purchase discounts on marketable securities, net	(333)	(873)
Net foreign currency (gains) losses	(275)	138
Deferred income taxes	179	737
Provision for doubtful accounts receivable	373	157
Changes in operating assets and liabilities:
Accounts receivable	11,557	(7,455)
Prepaid expenses and other current assets	(3,143)	3,129
Other assets	(5,684)	(9,647)
Accounts payable	(4,569)	(1,591)
Accrued expenses and other current liabilities	(1,032)	1,044
Deferred revenue	3,056	14,971
Operating lease liabilities	(3,734)	(3,997)
Net cash provided by operating activities	39,923	21,500
Cash flows from investing activities
Purchases of marketable securities	(116,400)	(93,259)
Proceeds from maturities of marketable securities	460,982	95,138
Proceeds from sales of marketable securities	25,959	17,279
Capitalized software development costs	(7,838)	(3,751)
Purchases of property and equipment	(2,515)	(3,461)
Cash paid for pending acquisition	(121,433)	0
Purchases of intangible assets	(2,333)	0
Net cash provided by investing activities	236,422	11,946
Cash flows from financing activities
Proceeds from issuance of convertible senior notes, net of issuance costs	0	487,163
Purchase of capped calls related to convertible senior notes	0	(46,150)
Proceeds from exercises of stock options	14,287	8,371
Proceeds from employee stock purchase plan	3,608	2,552
Acquisition of common stock for tax withholding obligations	(6,128)	(3,372)
Financed purchases of property and equipment	(394)	(314)
Net cash provided by financing activities	11,373	448,250
Effect of foreign currency exchange rate changes on cash, cash equivalents, and restricted cash	130	308
Net increase in cash, cash equivalents, and restricted cash	287,848	482,004
Cash, cash equivalents, and restricted cash, beginning of period	120,502	46,455
Cash, cash equivalents, and restricted cash, end of period	408,350	528,459
Reconciliation of cash, cash equivalents, and restricted cash to the consolidated balance sheets
Cash and cash equivalents at end of period	408,070	528,197
Restricted cash included within prepaid expenses and other current assets at end of period	19	19
Restricted cash included within other assets at end of period	261	243
Total cash, cash equivalents, and restricted cash at end of period shown in the consolidated statements of cash flows	408,350	528,459
Non-cash financing and investing activities
Stock-based compensation capitalized for software development	891	296
Capitalized software development costs included in accounts payable and accrued expenses and other current liabilities at end of period	461	182
Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities at end of period	808	360
Leased assets obtained in exchange for new operating lease liabilities	$ 282	$ 2,195

Company Overview

Company Overview	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company Overview	Company Overview BlackLine, Inc. and its subsidiaries (the “Company” or “BlackLine”) provide financial accounting close solutions delivered primarily as Software as a Service (“SaaS”). The Company’s solutions enable its customers to address various aspects of their financial close process including account reconciliations, variance analysis of account balances, journal entry capabilities, and certain types of data matching capabilities. The Company is headquartered in Woodland Hills, California and has offices in the Netherlands, Canada, France, Singapore, the United Kingdom, Germany, Australia, Hong Kong, Romania, and Poland.

Basis of Presentation, Signific

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements	Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements The accompanying condensed consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes included in the Annual Report on Form 10-K for the fiscal year ended December 31, 2019 filed with the Securities and Exchange Commission (“SEC”) on February 27, 2020. The condensed consolidated financial statements are unaudited and have been prepared on a basis consistent with that used to prepare the audited annual consolidated financial statements and include, in the opinion of management, all adjustments, consisting of normal and recurring items, necessary for the fair statement of the condensed consolidated financial statements. The condensed consolidated balance sheet at December 31, 2019 was derived from audited financial statements, but does not include all disclosures required by GAAP. The operating results for the quarter and nine months ended September 30, 2020 are not necessarily indicative of the results expected for the full year ending December 31, 2020. Use of estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. The extent to which COVID-19 impacts the Company’s business and financial results will depend on numerous continuously evolving factors including, but not limited to, the magnitude and duration of COVID-19, including resurgences; the impact on the Company’s employees; the extent to which it will impact worldwide macroeconomic conditions, including interest rates, employment rates, and health insurance coverage; the speed and degree of the anticipated recovery, as well as variability in such recovery across different geographies, industries, and markets; and governmental and business reactions to the pandemic. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of COVID-19 at September 30, 2020 and through the date of this report. The accounting matters assessed included, but were not limited to, the Company’s allowance for doubtful accounts and credit losses, and the carrying value of goodwill and other long-lived assets. While there was not a material impact to the Company’s consolidated financial statements at and for the quarter and nine months ended September 30, 2020, the Company’s future assessment of the magnitude and duration of COVID-19, as well as other factors could result in material impacts to the Company’s consolidated financial statements in future reporting periods. Significant accounting policies The Company’s significant accounting policies are detailed in “Note 2: Summary of Significant Accounting Policies" of the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. Except as noted below, there have been no material changes to the Company’s significant accounting policies. Investments in Marketable Securities The Company periodically assesses its portfolio of marketable securities for impairment. For debt securities in an unrealized loss position, this assessment first takes into account the Company’s intent to sell, or whether it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of these criteria are met, the debt security’s amortized cost basis is written down to fair value through other income (expense), net. For debt securities in an unrealized loss position that do not meet the aforementioned criteria, the Company assesses whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and any adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss may exist, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses will be recorded through other income (expense), net, limited by the amount that the fair value is less than the amortized cost basis. Any additional impairment not recorded through an allowance for credit losses is recognized in accumulated other comprehensive loss in the condensed consolidated statements of stockholders’ equity. Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when the Company believes the uncollectibility of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. The Company has not recorded any credit losses for the quarter and nine months ended September 30, 2020. The Company has not recorded any impairment charges for unrealized losses in the periods presented. Accounts Receivable and Allowances Accounts receivable are recorded and carried at the original invoiced amount less an allowance for any potential uncollectible amounts. The Company makes estimates of expected credit losses for the allowance for doubtful accounts and allowance for cancellations and credits based upon its assessment of various factors, including historical experience, the age of the accounts receivable balances, credit quality of its customers, current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect its ability to collect from customers. The estimated credit loss allowance for doubtful accounts is recorded as general and administrative expenses, while the estimated credit loss allowance for cancellations and credits is recorded as a reduction in revenue on the condensed consolidated statements of operations. Revision of Previously-Issued Financial Statements As previously disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, in connection with the preparation of its 2019 annual financial statements, the Company identified an error in its historical provision for income taxes, which resulted in an understatement of its tax provision and deferred tax liabilities in its previously-issued financial statements. The error resulted from the recognition of a foreign deferred tax asset that should not have been recognized for the difference in international entity income for statutory purposes and international entity income included on the consolidated income tax provision. There was no corresponding domestic benefit of this incremental foreign tax expense due to the U.S. entity being subject to a full valuation allowance. Although the Company assessed the materiality of the errors and determined the amounts were not material to previously-issued financial statements, the Company did revise its previously-issued 2018 and 2017 annual financial statements to correct for such tax error, as well as certain prior period immaterial disclosure errors, in connection with the filing of its 2019 Annual Report on Form 10-K, and disclosed that it would be revising its 2019 consolidated interim financial statements in connection with the Company’s 2020 Form 10-Q filings. In connection with the filing of this Quarterly Report on Form 10-Q, the Company has revised the accompanying consolidated condensed interim financial statements for the quarter and nine months ended September 30, 2019 to correct for the impact of such errors, which originated in periods prior to 2019. The accompanying footnotes have also been corrected to reflect the impact of the revisions of the previously-filed consolidated interim financial statements. The following tables present the effect of the revision for the financial statement line items adjusted in the affected periods. Condensed Consolidated Statements of Operations Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands, except per share data) Provision for income taxes $ 206 $ (36) $ 170 Net loss $ (8,912) $ 36 $ (8,876) Net loss attributable to BlackLine, Inc. $ (9,242) $ 36 $ (9,206) Basic net loss per share attributable to BlackLine, Inc. $ (0.17) $ — $ (0.17) Diluted net loss per share attributable to BlackLine, Inc. $ (0.17) $ — $ (0.17) Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands, except per share data) Provision for income taxes $ 557 $ 299 $ 856 Net loss $ (23,135) $ (299) $ (23,434) Net loss attributable to BlackLine, Inc. $ (23,050) $ (299) $ (23,349) Basic net loss per share attributable to BlackLine, Inc. $ (0.42) $ — $ (0.42) Diluted net loss per share attributable to BlackLine, Inc. $ (0.42) $ — $ (0.42) Condensed Consolidated Statements of Comprehensive Loss Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss $ (8,912) $ 36 $ (8,876) Comprehensive loss $ (8,925) $ 36 $ (8,889) Comprehensive loss attributable to BlackLine, Inc. $ (8,421) $ 36 $ (8,385) Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss $ (23,135) $ (299) $ (23,434) Comprehensive loss $ (22,614) $ (299) $ (22,913) Comprehensive loss attributable to BlackLine, Inc. $ (21,787) $ (299) $ (22,086) Condensed Consolidated Statements of Stockholders' Equity Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised Accumulated Deficit (in thousands) Balance at June 30, 2019 $ (144,348) $ (2,637) $ (146,985) Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (8,403) $ 36 $ (8,367) Balance at September 30, 2019 $ (152,751) $ (2,601) $ (155,352) Total Equity Balance at June 30, 2019 $ 327,185 $ (2,637) $ 324,548 Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (9,242) $ 36 $ (9,206) Balance at September 30, 2019 $ 396,421 $ (2,601) $ 393,820 Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised Accumulated Deficit (in thousands) Balance at December 31, 2018 $ (130,594) $ (2,302) $ (132,896) Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (22,157) $ (299) $ (22,456) Balance at September 30, 2019 $ (152,751) $ (2,601) $ (155,352) Total Equity Balance at December 31, 2018 $ 321,569 $ (2,302) $ 319,267 Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (23,050) $ (299) $ (23,349) Balance at September 30, 2019 $ 396,421 $ (2,601) $ 393,820 Condensed Consolidated Statements of Cash Flows Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss attributable to BlackLine, Inc. $ (23,050) $ (299) $ (23,349) Net loss $ (23,135) $ (299) $ (23,434) Deferred income taxes $ 35 $ 702 $ 737 Accrued expenses and other current liabilities $ 1,447 $ (403) $ 1,044 Recently-issued accounting pronouncements not yet adopted In March 2020, the Financial Accounting Standards Board (“FASB”) issued guidance, which provides temporary optional guidance to ease the potential burden in accounting for reference rate reform. The new guidance provides optional expedients and exceptions for applying generally accepted accounting principles to transactions affected by reference rate reform if certain criteria are met. These transactions include contract modifications, hedging relationships, and sale or transfer of debt securities classified as held-to-maturity. Entities may apply the provisions of the new standard as of the beginning of the reporting period when the election is made (i.e., as early as the first quarter of 2020). Unlike other topics, the provisions of this update are only available until December 31, 2022, when the reference rate replacement activity is expected to be completed. The Company has not adopted the provisions of the new standard and does not expect it to have a material impact on the Company’s condensed consolidated financial statements. In June 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) . This standard eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, the new guidance modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. For public business entities, it is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years using the fully retrospective or modified retrospective method. Early adoption is permitted but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company is currently evaluating the potential impact of this standard on its condensed consolidated financial statements. Recently adopted accounting pronouncements In May 2020, the Securities Exchange Commission (“SEC”) issued a final rule that amended the disclosure requirements applicable to acquisitions and dispositions of businesses. The changes include: updating the tests used to determine significance and expanding the use of pro forma financial information when measuring significance; conforming the significance threshold and tests for a disposed business to those used for an acquired business; permitting abbreviated financial statements for certain acquisitions of a component of an entity; revising the pro forma financial information requirements; reducing the maximum number of years for which financial statements under Regulation S-X Rule 3-05 are required to two years; and modifying the disclosure requirements relating to the aggregate effect of acquisitions for which financial statements are not (or not yet) required. The amendments are intended to improve the financial information about acquired or disposed businesses provided to investors, facilitate more timely access to capital, and reduce the complexity and costs to prepare the disclosures. The Company early adopted this rule in the quarter ended June 30, 2020, and the adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements. In June 2016, the FASB issued Accounting Standard Update (“ASU”) 2016-13 , Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ASU 2016-13 replaced the incurred loss impairment methodology under current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 requires use of a forward-looking expected credit loss model for accounts receivables, loans, and other financial instruments. Adoption of the standard requires using a modified retrospective approach through a cumulative-effect adjustment to retained earnings as of the effective date to align existing credit loss methodology with the new standard. In November 2019, the FASB issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses . ASU 2019-11 requires entities that did not adopt the amendments in ASU 2016-13 as of November 2019 to adopt ASU 2019-11. This ASU contains the same effective dates and transition requirements as ASU 2016-13. The Company adopted this guidance effective January 1, 2020, and the adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements. In August 2018, the FASB issued guidance which modifies the disclosure requirements of fair value measurements in Topic 820, Fair Value Measurement , based on the concepts in FASB Concepts Statement, Conceptual Framework for Financial Reporting—Chapter 8: Notes to Financial Statements , including the consideration of costs and benefits. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company adopted this guidance effective January 1, 2020, and the adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements.

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interest	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Redeemable Non-Controlling Interest	Redeemable Non-Controlling Interest In September 2018, the Company entered into an agreement with Japanese Cloud Computing and M30 LLC (the “Investors”) to engage in the investment, organization, management, and operation of a Japanese subsidiary (“BlackLine K.K.”) of the Company that is focused on the sale of the Company's products in Japan. In October 2018, the Company initially contributed approximately $4.5 million in cash in exchange for 51% of the outstanding common stock of BlackLine K.K. As the Company controls a majority stake in BlackLine K.K., the entity has been consolidated. All of the common stock held by the Investors is callable by the Company or puttable by the Investors upon certain contingent events. Should the call or put option be exercised, the redemption value will be determined based upon a prescribed formula derived from the discrete revenues of BlackLine K.K. and the Company and may be settled, at the Company’s discretion, with Company stock or cash. As a result of the put right available to the Investors in the future, the redeemable non-controlling interest in BlackLine K.K. are classified outside of permanent equity in the Company’s condensed consolidated balance sheet, and the balance is reported at the greater of the initial carrying amount adjusted for the redeemable non-controlling interest’s share of earnings, or its estimated redemption value. The resulting changes in the estimated redemption amount are recorded within retained earnings or, in the absence of retained earnings, additional paid-in-capital. The following table summarizes the activity in the redeemable non-controlling interest for the periods indicated below: Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Balance at beginning of period $ 7,190 $ 4,118 $ 4,905 $ 4,387 Net loss attributable to redeemable non-controlling interest (excluding adjustment to non-controlling interest) (425) (509) (1,081) (978) Foreign currency translation 44 5 65 151 Adjustment to redeemable non-controlling interest 1,319 839 4,239 893 Balance at end of period $ 8,128 $ 4,453 $ 8,128 $ 4,453 During the third quarter of 2020, the Company identified that, commencing in 2019, it had incorrectly calculated its quarterly adjustment to the carrying value of its redeemable non-controlling interest, which resulted in an overstatement of the adjustment attributable to non-controlling interest in its consolidated statement of operations totaling $0.4 million for the quarter and nine months ended September 30, 2019; $0.5 million and $0.9 million for the quarter and year ended December 31, 2019; $1.2 million for the quarter ended March 31, 2020; and $0.6 million for the six months ended June 30, 2020, as well as an understatement of the adjustment attributable to non-controlling interest in its consolidated statement of operations totaling $0.6 million for the quarter ended June 30, 2020. At December 31, 2019, the carrying value of the redeemable non-controlling interest in the Company's consolidated balance sheet was overstated by $0.9 million. The Company corrected the $1.5 million cumulative prior-period error in the quarter ended September 30, 2020 to correctly state the carrying value of the redeemable non-controlling interest in its consolidated balance sheet.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2020
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Investments in Marketable Securities Investments in marketable securities presented within current assets on the condensed consolidated balance sheet consisted of the following: September 30, 2020 Amortized Gross Gross Fair Value (in thousands) Marketable securities U.S. treasury securities $ 4,504 $ 6 $ — $ 4,510 Corporate bonds 110,104 255 (24) 110,335 Commercial paper 2,588 — — 2,588 $ 117,196 $ 261 $ (24) $ 117,433 December 31, 2019 Amortized Gross Gross Fair Value (in thousands) Marketable securities U.S. treasury securities $ 382,269 $ 67 $ (1) $ 382,335 Corporate bonds 77,009 63 (18) 77,054 Commercial paper 28,126 — — 28,126 $ 487,404 $ 130 $ (19) $ 487,515 Net gains and losses related to maturities of marketable securities that were reclassified from accumulated other comprehensive loss to earnings, and included in general and administrative expenses, in the unaudited condensed consolidated statements of operations were $(0.3) million and $0.3 million for the quarter and nine months ended September 30, 2020, respectively. Net gains and losses related to maturities of marketable securities that were reclassified from accumulated other comprehensive loss to earnings, and included in general and administrative expenses, in the unaudited condensed consolidated statements of operations were $0.1 million and $0.7 million for the quarter and nine months ended September 30, 2019, respectively. Net gains and losses are determined using the specific identification method. During the quarters ended September 30, 2020 and 2019, there were no material realized gains or losses related to sales of marketable securities recognized in the Company's unaudited condensed consolidated statements of operations. During the nine months ended September 30, 2020, there were $0.1 million of realized losses related to the sale of one marketable security recognized in the Company’s unaudited condensed consolidated statements of operations. During the nine months ended September 30, 2019, there were no material realized gains or losses related to sales of marketable securities recognized in the Company’s unaudited condensed consolidated statements of operations. Marketable securities in a continuous loss position for less than 12 months had an estimated fair value of $17.0 million and an immaterial amount of unrealized losses at September 30, 2020, and an estimated fair value of $83.9 million and an immaterial amount of unrealized losses at December 31, 2019. At September 30, 2020, there were no marketable securities in a continuous loss position for greater than 12 months. The Company’s marketable securities have a contractual maturity of less than one year. The amortized cost and fair values of marketable securities, by remaining contractual maturity, were as follows: September 30, 2020 Amortized Fair Value (in thousands) Maturing within 1 year $ 117,196 $ 117,433 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, Cash paid for pending acquisition $ 121,433 $ — Partner referral fees 702 833 Other prepaid expenses and other current assets 15,222 11,997 $ 137,357 $ 12,830 Other Assets Other assets consisted of the following (in thousands): September 30, December 31, Deferred customer contract acquisition costs $ 54,791 $ 49,709 Restricted cash 261 250 Capitalized software implementation costs 2,002 1,237 Other assets 1,524 1,687 $ 58,578 $ 52,883 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities were comprised of the following (in thousands): September 30, December 31, Accrued salaries and employee benefits $ 20,769 $ 20,775 Accrued income and other taxes payable 2,919 4,198 Other accrued expenses and current liabilities 5,858 5,125 $ 29,546 $ 30,098

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following table summarizes the Company’s financial assets and liabilities measured at fair value on a recurring basis by level, within the fair value hierarchy. Financial assets and financial liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement (in thousands): September 30, 2020 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 362,689 $ — $ — $ 362,689 Marketable securities U.S. treasury securities 4,510 — — 4,510 Corporate bonds — 110,335 — 110,335 Commercial paper — 2,588 — 2,588 Total assets $ 367,199 $ 112,923 $ — $ 480,122 Liabilities Contingent consideration $ — $ — $ 6,214 $ 6,214 Total liabilities $ — $ — $ 6,214 $ 6,214 December 31, 2019 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 39,767 $ — $ — $ 39,767 Marketable securities U.S. treasury securities 382,335 — — 382,335 Corporate bonds — 77,054 — 77,054 Commercial paper — 28,126 — 28,126 Total assets $ 422,102 $ 105,180 $ — $ 527,282 Liabilities Contingent consideration $ — $ — $ 6,362 $ 6,362 Total liabilities $ — $ — $ 6,362 $ 6,362 The following table summarizes the changes in the contingent consideration liability (in thousands): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Beginning fair value $ 6,286 $ 6,500 $ 6,362 $ 6,316 Change in fair value (72) 129 (148) 313 Ending fair value $ 6,214 $ 6,629 $ 6,214 $ 6,629 The fair value of contingent consideration is determined by discounting estimated future taxable income. The significant inputs used in the fair value measurement of contingent consideration are the timing and amount of taxable income in any given period and the discount rate, which considers the risk associated with the forecasted taxable income. Significant changes in the estimated future taxable income and the periods in which they are generated would significantly impact the fair value of the contingent consideration liability.

Convertible Senior Notes

Convertible Senior Notes	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes On August 13, 2019, the Company issued 0.125% Convertible Senior Notes (the “Notes”) due in 2024 for aggregate gross proceeds of $500.0 million, which includes the initial purchasers’ option of $65.0 million aggregate principal amount, in a private placement in reliance on Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”). The initial resale of the Notes by the initial purchasers to qualified institutional buyers was exempt from registration pursuant to Rule 144A under the Securities Act. The Notes were issued pursuant to an Indenture (the “Indenture”) between the Company and U.S. Bank National Association, as trustee (the “Trustee”). The Notes consisted of the following (in thousands): September 30, 2020 Liability: Principal $ 500,000 Unamortized debt discount and issuance costs (98,783) Net carrying amount $ 401,217 Carrying amount of the equity component $ 111,230 The Company carries the Notes at face value less unamortized discount and issuance costs on its condensed consolidated balance sheet and presents the fair value for disclosure purposes only. The estimated fair value of the Notes, based on a market approach at September 30, 2020 was approximately $692.8 million, which represents a Level 2 valuation. The estimated fair value was determined based on the actual bids and offers of the Notes in an over-the-counter market on the last trading day of the period. During the quarter ended September 30, 2020, the Company recognized $5.8 million of interest expense related to the amortization of debt discount and issuance costs and $0.2 million of coupon interest expense. During the nine months ended September 30, 2020, the Company recognized $16.9 million of interest expense related to the amortization of debt discount and issuance costs and $0.5 million of coupon interest expense. During the quarter and nine months ended September 30, 2019, the Company recognized $2.9 million of interest expense related to the amortization of debt discount and issuance costs and $0.1 million of coupon interest expense. At September 30, 2020, the remaining life of the Notes was approximately 46 months. The Notes were not convertible at September 30, 2020.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contingent consideration —On September 3, 2013, BlackLine Systems, Inc. was acquired by BlackLine, Inc. (the “2013 Acquisition”). In conjunction with the 2013 Acquisition, option holders of BlackLine Systems, Inc. were allowed to cancel their stock option rights and receive a cash payment equal to the amount of calculated gain (less applicable expense and other items) had they exercised their stock options and then sold their common shares as part of the 2013 Acquisition. As a condition of the 2013 Acquisition, the Company is required to pay additional cash consideration to certain equity holders if the Company realizes a tax benefit from the use of net operating losses generated from the stock option exercises concurrent with the 2013 Acquisition. The maximum contingent cash consideration to be distributed is $8.0 million. The fair value of the contingent consideration was $6.2 million and $6.4 million at September 30, 2020 and December 31, 2019, respectively. Litigation —From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company is not currently a party to any legal proceedings, nor is it aware of any pending or threatened litigation, that would have a material adverse effect on the Company’s business, operating results, cash flows, or financial condition should such litigation be resolved unfavorably. Indemnification — In the ordinary course of business, the Company may provide indemnification of varying scope and terms to customers, vendors, investors, directors, and officers with respect to certain matters, including, but not limited to, losses arising out of its breach of such agreements, services to be provided by the Company, or from intellectual property infringement claims made by third parties. These indemnification provisions may survive termination of the underlying agreement and the maximum potential amount of future payments the Company could be required to make under these indemnification provisions may not be subject to maximum loss clauses. The maximum potential amount of future payments the Company could be required to make under these indemnification provisions is indeterminable. The Company has never paid a material claim, nor has it been sued in connection with

Equity Awards

Equity Awards	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Equity Awards	Equity Awards Stock-based compensation expense Stock-based compensation expense recorded in the Company’s unaudited condensed consolidated statements of operations was as follows (in thousands): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Cost of revenues $ 1,871 $ 1,431 $ 4,900 $ 3,478 Sales and marketing 5,675 4,522 15,645 11,074 Research and development 1,954 1,452 4,918 3,631 General and administrative 3,826 2,736 9,935 6,422 $ 13,326 $ 10,141 $ 35,398 $ 24,605 For the quarters ended September 30, 2020 and 2019, stock-based compensation capitalized as an asset was $0.4 million and $0.1 million, respectively. For the nine months ended September 30, 2020 and 2019, stock-based compensation capitalized as an asset was $0.9 million and $0.3 million, respectively. Stock options The following table summarizes activity for awards that contain service-only vesting conditions (in thousands): Outstanding at December 31, 2019 3,486 Granted 578 Exercised (804) Forfeited/canceled (44) Outstanding at September 30, 2020 3,216 Restricted stock units The following table summarizes activity for restricted stock units (in thousands): Nonvested at December 31, 2019 1,654 Granted 1,053 Vested (533) Forfeited/canceled (85) Nonvested at September 30, 2020 2,089 Stock options with performance conditions In October 2016, the Company granted options to purchase 682,800 shares of common stock at an exercise price of $14.00 per share to two officers that vest upon meeting certain performance conditions and continued service. The performance conditions included meeting yearly cash flow targets and cumulative annual recurring revenue targets through 2019. If each yearly cash flow target was met through 2019, but the full cumulative annual recurring target through 2019 was not met, the executive officers are still able to vest in the award if an additional cash flow target for 2020 and a cumulative annual recurring revenue target through 2020 are achieved. The cash flow performance targets for each year are determined concurrently with the annual budget process. The cash flow performance targets for the final year were set during the quarter ended March 31, 2019, resulting in a grant date being established. The total fair value of the awards at grant date was approximately $24 million. At September 30, 2020, the Company has determined that the achievement of the performance targets is not probable and, accordingly, no stock-based compensation expense has been recorded for these awards. On July 1, 2020, 200,000 stock options with performance conditions were canceled upon the change in the employment status of one of the officers.

Unearned Revenue and Performanc

Unearned Revenue and Performance Obligations	9 Months Ended
	Sep. 30, 2020
Unearned Revenue And Performance Obligations [Abstract]
Unearned Revenue and Performance Obligations	Unearned Revenue and Performance Obligations Revenue totaling $147.5 million and $117.8 million was recognized during the nine months ended September 30, 2020 and 2019, respectively, that was previously included in the deferred revenue balance at December 31, 2019 and 2018, respectively. Contracted not recognized revenue was $411.3 million at September 30, 2020, of which the Company expects to recognize approximately 59% over the next 12 months and the remainder thereafter.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In determining quarterly provisions for income taxes, the Company uses the annual estimated effective tax rate applied to the actual year-to-date loss, adjusted for discrete items arising in that quarter. The Company’s annual estimated effective tax rate differs from the U.S. federal statutory rate of 21% primarily as a result of state taxes, foreign taxes, and changes in the Company’s valuation allowance for domestic income taxes. For the quarters ended September 30, 2020 and 2019, the Company recorded $0.6 million and $0.2 million in income tax expense, respectively. For the nine months ended September 30, 2020 and 2019, the Company recorded $0.9 million and $0.9 million in income tax expense, respectively. The increase in income tax expense for the quarter ended September 30, 2020, compared to the quarter ended September 30, 2019, resulted primarily from changes in the mix of profitable foreign jurisdictions and higher foreign withholding taxes. Income tax expense for the nine months ended September 30, 2020, compared to the nine months ended September 30, 2019, remained relatively flat. For the quarters and nine months ended September 30, 2020 and 2019, the Company maintained a full valuation allowance on its U.S. federal and state net deferred tax assets as it was more likely than not that those deferred tax assets will not be realized.

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share amounts): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net loss attributable to BlackLine, Inc. $ (8,751) $ (9,206) $ (29,926) $ (23,349) Denominator: Weighted average shares 57,063 55,480 56,619 55,164 Add: Dilutive effect of securities — — — — Shares used to calculate diluted net loss per share 57,063 55,480 56,619 55,164 Basic net loss per share attributable to BlackLine, Inc. $ (0.15) $ (0.17) $ (0.53) $ (0.42) Diluted net loss per share attributable to BlackLine, Inc. $ (0.15) $ (0.17) $ (0.53) $ (0.42) As further described in Note 3, during the third quarter of 2020, the Company identified that, commencing in 2019, it had incorrectly calculated its quarterly adjustment to the carrying value of its redeemable non-controlling interest in its consolidated balance sheet, with a corresponding impact to net loss attributable to BlackLine, Inc., as well as basic and diluted net loss per share attributable to BlackLine, Inc. in its consolidated statement of operations. Such errors resulted in a $0.4 million ($0.01 per basic and diluted share) overstatement of net loss attributable to BlackLine, Inc. for the quarter and nine months ended September 30, 2019. The Company corrected for the cumulative impact of its prior-period errors during the third quarter of 2020, which resulted in a reduction of its net loss attributable to BlackLine, Inc. of $1.5 million ($0.03 per basic and diluted share) and $0.9 million($0.02 per basic and diluted share) for the quarter and nine months ended September 30, 2020, respectively. The following potentially dilutive shares were excluded from the calculation of diluted net loss per share attributable to common stockholders because they were anti-dilutive (in thousands): Nine Months Ended September 30, 2020 2019 Stock options with service-only vesting conditions 3,216 3,696 Stock options with performance conditions 483 683 Restricted stock units 2,089 1,692 Total shares excluded from net loss per share 5,788 6,071 Additionally, approximately 6.8 million shares underlying the conversion option in the Notes are not considered in the calculation of diluted net loss per share as the effect would be anti-dilutive. The shares are subject to adjustment, up to approximately 9.4 million shares for the Notes, if certain corporate events occur prior to the maturity date or if the Company issues a notice of redemption. The Company uses the treasury stock method for calculating any potential dilutive effect of the conversion option on diluted net income per share, if applicable. During the nine months ended September 30, 2020, the average market price of the Company’s common stock did not exceed the conversion price of the Notes of $73.40 per share.

Geographic Information

Geographic Information	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Geographic Information	Geographic Information The Company disaggregates its revenue from contracts with customers by geographic location, as it believes it best depicts how the nature, amount, timing, and uncertainty of its revenues and cash flows are affected by economic factors. The following table sets forth the Company’s revenues by geographic region (in thousands): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 United States $ 68,058 $ 58,588 $ 192,784 $ 162,487 International 22,099 16,337 63,243 46,231 $ 90,157 $ 74,925 $ 256,027 $ 208,718

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 2, 2020, the Company completed the acquisition (the “Rimilia Acquisition”) of Rimilia Hol dings Ltd. for consideration of $150 million in cash (subject to working capital adjustments), of which $120 million was payable at the closing of the acquisition with additional cash payments of up to $30 million payable upon certain earnout conditions being met. The Company funded the Rimilia Acquisition on September 30, 2020, in advance of the closing. The acquisition expands the Company’s capabilities into an adjacent area, adding accounts receivable automation to financial close automation and accelerating the Company’s larger, long-term plan for transforming and modernizing Finance and Accounting. Due to the limited time since the acquisition date, the initial accounting for the business combination is incomplete. As a result, the Company is unable to provide the amounts recognized as of the acquisition date for the major classes of assets acquired and liabilities assumed. On September 30, 2020, the Compensation Committee of the Board of Directors of BlackLine, Inc. approved restricted stock unit grants, to become effective upon the close of the Rimilia Acquisition, which closed on October 2, 2020, to newly acquired employees totaling 0.1 million shares. Each restricted stock unit entitles the recipient to receive one share of common stock upon vesting of the award. The vast majority of the restricted stock units will vest as to one-half of the total number of units awarded on the first anniversary of November 20, 2020 and one-half of the total number of units awarded on the second anniversary of November 20, 2020. On October 30, 2020, the Compensation Committee of the Board of Directors of BlackLine, Inc. approved restricted stock unit grants to employees totaling 0.1 million shares. Each restricted stock unit entitles the recipient to receive one share of common stock upon vesting of the award. The vast majority of the restricted stock units will vest as to one-fourth of the total number of units awarded on the first anniversary of November 20, 2020 and quarterly thereafter for 12 consecutive quarters.

Basis of Presentation, Signif_2

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. The extent to which COVID-19 impacts the Company’s business and financial results will depend on numerous continuously evolving factors including, but not limited to, the magnitude and duration of COVID-19, including resurgences; the impact on the Company’s employees; the extent to which it will impact worldwide macroeconomic conditions, including interest rates, employment rates, and health insurance coverage; the speed and degree of the anticipated recovery, as well as variability in such recovery across different geographies, industries, and markets; and governmental and business reactions to the pandemic. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of COVID-19 at September 30, 2020 and through the date of this report. The accounting matters assessed included, but were not limited to, the Company’s allowance for doubtful accounts and credit losses, and the carrying value of goodwill and other long-lived assets. While there was not a material impact to the Company’s consolidated financial statements at and for the quarter and nine months ended September 30, 2020, the Company’s future assessment of the magnitude and duration of COVID-19, as well as other factors could result in material impacts to the Company’s consolidated financial statements in future reporting periods.
Investments in Marketable Securities	Investments in Marketable Securities The Company periodically assesses its portfolio of marketable securities for impairment. For debt securities in an unrealized loss position, this assessment first takes into account the Company’s intent to sell, or whether it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of these criteria are met, the debt security’s amortized cost basis is written down to fair value through other income (expense), net. For debt securities in an unrealized loss position that do not meet the aforementioned criteria, the Company assesses whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and any adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss may exist, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses will be recorded through other income (expense), net, limited by the amount that the fair value is less than the amortized cost basis. Any additional impairment not recorded through an allowance for credit losses is recognized in accumulated other comprehensive loss in the condensed consolidated statements of stockholders’ equity. Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when the Company believes the uncollectibility of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. The Company has not recorded any credit losses for the quarter and nine months ended September 30, 2020. The Company has not recorded any impairment charges for unrealized losses in the periods presented.
Accounts Receivable and Allowances	Accounts Receivable and Allowances Accounts receivable are recorded and carried at the original invoiced amount less an allowance for any potential uncollectible amounts. The Company makes estimates of expected credit losses for the allowance for doubtful accounts and allowance for cancellations and credits based upon its assessment of various factors, including historical experience, the age of the accounts receivable balances, credit quality of its customers, current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect its ability to collect from customers. The estimated credit loss allowance for doubtful accounts is recorded as general and administrative expenses, while the estimated credit loss allowance for cancellations and credits is recorded as a reduction in revenue on the condensed consolidated statements of operations.
Revision of Previously Issued Financial Statements	Revision of Previously-Issued Financial Statements As previously disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, in connection with the preparation of its 2019 annual financial statements, the Company identified an error in its historical provision for income taxes, which resulted in an understatement of its tax provision and deferred tax liabilities in its previously-issued financial statements. The error resulted from the recognition of a foreign deferred tax asset that should not have been recognized for the difference in international entity income for statutory purposes and international entity income included on the consolidated income tax provision. There was no corresponding domestic benefit of this incremental foreign tax expense due to the U.S. entity being subject to a full valuation allowance. Although the Company assessed the materiality of the errors and determined the amounts were not material to previously-issued financial statements, the Company did revise its previously-issued 2018 and 2017 annual financial statements to correct for such tax error, as well as certain prior period immaterial disclosure errors, in connection with the filing of its 2019 Annual Report on Form 10-K, and disclosed that it would be revising its 2019 consolidated interim financial statements in connection with the Company’s 2020 Form 10-Q filings. In connection with the filing of this Quarterly Report on Form 10-Q, the Company has revised the accompanying consolidated condensed interim financial statements for the quarter and nine months ended September 30, 2019 to correct for the impact of such errors, which originated in periods prior to 2019. The accompanying footnotes have also been corrected to reflect the impact of the revisions of the previously-filed consolidated interim financial statements. The following tables present the effect of the revision for the financial statement line items adjusted in the affected periods. Condensed Consolidated Statements of Operations Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands, except per share data) Provision for income taxes $ 206 $ (36) $ 170 Net loss $ (8,912) $ 36 $ (8,876) Net loss attributable to BlackLine, Inc. $ (9,242) $ 36 $ (9,206) Basic net loss per share attributable to BlackLine, Inc. $ (0.17) $ — $ (0.17) Diluted net loss per share attributable to BlackLine, Inc. $ (0.17) $ — $ (0.17) Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands, except per share data) Provision for income taxes $ 557 $ 299 $ 856 Net loss $ (23,135) $ (299) $ (23,434) Net loss attributable to BlackLine, Inc. $ (23,050) $ (299) $ (23,349) Basic net loss per share attributable to BlackLine, Inc. $ (0.42) $ — $ (0.42) Diluted net loss per share attributable to BlackLine, Inc. $ (0.42) $ — $ (0.42) Condensed Consolidated Statements of Comprehensive Loss Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss $ (8,912) $ 36 $ (8,876) Comprehensive loss $ (8,925) $ 36 $ (8,889) Comprehensive loss attributable to BlackLine, Inc. $ (8,421) $ 36 $ (8,385) Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss $ (23,135) $ (299) $ (23,434) Comprehensive loss $ (22,614) $ (299) $ (22,913) Comprehensive loss attributable to BlackLine, Inc. $ (21,787) $ (299) $ (22,086) Condensed Consolidated Statements of Stockholders' Equity Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised Accumulated Deficit (in thousands) Balance at June 30, 2019 $ (144,348) $ (2,637) $ (146,985) Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (8,403) $ 36 $ (8,367) Balance at September 30, 2019 $ (152,751) $ (2,601) $ (155,352) Total Equity Balance at June 30, 2019 $ 327,185 $ (2,637) $ 324,548 Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (9,242) $ 36 $ (9,206) Balance at September 30, 2019 $ 396,421 $ (2,601) $ 393,820 Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised Accumulated Deficit (in thousands) Balance at December 31, 2018 $ (130,594) $ (2,302) $ (132,896) Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (22,157) $ (299) $ (22,456) Balance at September 30, 2019 $ (152,751) $ (2,601) $ (155,352) Total Equity Balance at December 31, 2018 $ 321,569 $ (2,302) $ 319,267 Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (23,050) $ (299) $ (23,349) Balance at September 30, 2019 $ 396,421 $ (2,601) $ 393,820 Condensed Consolidated Statements of Cash Flows Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss attributable to BlackLine, Inc. $ (23,050) $ (299) $ (23,349) Net loss $ (23,135) $ (299) $ (23,434) Deferred income taxes $ 35 $ 702 $ 737 Accrued expenses and other current liabilities $ 1,447 $ (403) $ 1,044
Recently-issued Not Yet Adopted and Adopted Accounting Pronouncements	Recently-issued accounting pronouncements not yet adopted In March 2020, the Financial Accounting Standards Board (“FASB”) issued guidance, which provides temporary optional guidance to ease the potential burden in accounting for reference rate reform. The new guidance provides optional expedients and exceptions for applying generally accepted accounting principles to transactions affected by reference rate reform if certain criteria are met. These transactions include contract modifications, hedging relationships, and sale or transfer of debt securities classified as held-to-maturity. Entities may apply the provisions of the new standard as of the beginning of the reporting period when the election is made (i.e., as early as the first quarter of 2020). Unlike other topics, the provisions of this update are only available until December 31, 2022, when the reference rate replacement activity is expected to be completed. The Company has not adopted the provisions of the new standard and does not expect it to have a material impact on the Company’s condensed consolidated financial statements. In June 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) . This standard eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, the new guidance modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. For public business entities, it is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years using the fully retrospective or modified retrospective method. Early adoption is permitted but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company is currently evaluating the potential impact of this standard on its condensed consolidated financial statements. Recently adopted accounting pronouncements In May 2020, the Securities Exchange Commission (“SEC”) issued a final rule that amended the disclosure requirements applicable to acquisitions and dispositions of businesses. The changes include: updating the tests used to determine significance and expanding the use of pro forma financial information when measuring significance; conforming the significance threshold and tests for a disposed business to those used for an acquired business; permitting abbreviated financial statements for certain acquisitions of a component of an entity; revising the pro forma financial information requirements; reducing the maximum number of years for which financial statements under Regulation S-X Rule 3-05 are required to two years; and modifying the disclosure requirements relating to the aggregate effect of acquisitions for which financial statements are not (or not yet) required. The amendments are intended to improve the financial information about acquired or disposed businesses provided to investors, facilitate more timely access to capital, and reduce the complexity and costs to prepare the disclosures. The Company early adopted this rule in the quarter ended June 30, 2020, and the adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements. In June 2016, the FASB issued Accounting Standard Update (“ASU”) 2016-13 , Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ASU 2016-13 replaced the incurred loss impairment methodology under current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 requires use of a forward-looking expected credit loss model for accounts receivables, loans, and other financial instruments. Adoption of the standard requires using a modified retrospective approach through a cumulative-effect adjustment to retained earnings as of the effective date to align existing credit loss methodology with the new standard. In November 2019, the FASB issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses . ASU 2019-11 requires entities that did not adopt the amendments in ASU 2016-13 as of November 2019 to adopt ASU 2019-11. This ASU contains the same effective dates and transition requirements as ASU 2016-13. The Company adopted this guidance effective January 1, 2020, and the adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements. In August 2018, the FASB issued guidance which modifies the disclosure requirements of fair value measurements in Topic 820, Fair Value Measurement , based on the concepts in FASB Concepts Statement, Conceptual Framework for Financial Reporting—Chapter 8: Notes to Financial Statements , including the consideration of costs and benefits. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company adopted this guidance effective January 1, 2020, and the adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements.

Basis of Presentation, Signif_3

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Revisions for Financial Statement Line Items Adjusted in Affected Periods	The following tables present the effect of the revision for the financial statement line items adjusted in the affected periods. Condensed Consolidated Statements of Operations Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands, except per share data) Provision for income taxes $ 206 $ (36) $ 170 Net loss $ (8,912) $ 36 $ (8,876) Net loss attributable to BlackLine, Inc. $ (9,242) $ 36 $ (9,206) Basic net loss per share attributable to BlackLine, Inc. $ (0.17) $ — $ (0.17) Diluted net loss per share attributable to BlackLine, Inc. $ (0.17) $ — $ (0.17) Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands, except per share data) Provision for income taxes $ 557 $ 299 $ 856 Net loss $ (23,135) $ (299) $ (23,434) Net loss attributable to BlackLine, Inc. $ (23,050) $ (299) $ (23,349) Basic net loss per share attributable to BlackLine, Inc. $ (0.42) $ — $ (0.42) Diluted net loss per share attributable to BlackLine, Inc. $ (0.42) $ — $ (0.42) Condensed Consolidated Statements of Comprehensive Loss Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss $ (8,912) $ 36 $ (8,876) Comprehensive loss $ (8,925) $ 36 $ (8,889) Comprehensive loss attributable to BlackLine, Inc. $ (8,421) $ 36 $ (8,385) Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss $ (23,135) $ (299) $ (23,434) Comprehensive loss $ (22,614) $ (299) $ (22,913) Comprehensive loss attributable to BlackLine, Inc. $ (21,787) $ (299) $ (22,086) Condensed Consolidated Statements of Stockholders' Equity Quarter Ended September 30, 2019 As Previously Reported Adjustments As Revised Accumulated Deficit (in thousands) Balance at June 30, 2019 $ (144,348) $ (2,637) $ (146,985) Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (8,403) $ 36 $ (8,367) Balance at September 30, 2019 $ (152,751) $ (2,601) $ (155,352) Total Equity Balance at June 30, 2019 $ 327,185 $ (2,637) $ 324,548 Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (9,242) $ 36 $ (9,206) Balance at September 30, 2019 $ 396,421 $ (2,601) $ 393,820 Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised Accumulated Deficit (in thousands) Balance at December 31, 2018 $ (130,594) $ (2,302) $ (132,896) Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (22,157) $ (299) $ (22,456) Balance at September 30, 2019 $ (152,751) $ (2,601) $ (155,352) Total Equity Balance at December 31, 2018 $ 321,569 $ (2,302) $ 319,267 Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest $ (23,050) $ (299) $ (23,349) Balance at September 30, 2019 $ 396,421 $ (2,601) $ 393,820 Condensed Consolidated Statements of Cash Flows Nine Months Ended September 30, 2019 As Previously Reported Adjustments As Revised (in thousands) Net loss attributable to BlackLine, Inc. $ (23,050) $ (299) $ (23,349) Net loss $ (23,135) $ (299) $ (23,434) Deferred income taxes $ 35 $ 702 $ 737 Accrued expenses and other current liabilities $ 1,447 $ (403) $ 1,044

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interest (Tables)	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Summary of Redeemable Non-Controlling Interest	The following table summarizes the activity in the redeemable non-controlling interest for the periods indicated below: Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Balance at beginning of period $ 7,190 $ 4,118 $ 4,905 $ 4,387 Net loss attributable to redeemable non-controlling interest (excluding adjustment to non-controlling interest) (425) (509) (1,081) (978) Foreign currency translation 44 5 65 151 Adjustment to redeemable non-controlling interest 1,319 839 4,239 893 Balance at end of period $ 8,128 $ 4,453 $ 8,128 $ 4,453

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2020
Balance Sheet Related Disclosures [Abstract]
Schedule of Investments in Marketable Securities	Investments in marketable securities presented within current assets on the condensed consolidated balance sheet consisted of the following: September 30, 2020 Amortized Gross Gross Fair Value (in thousands) Marketable securities U.S. treasury securities $ 4,504 $ 6 $ — $ 4,510 Corporate bonds 110,104 255 (24) 110,335 Commercial paper 2,588 — — 2,588 $ 117,196 $ 261 $ (24) $ 117,433 December 31, 2019 Amortized Gross Gross Fair Value (in thousands) Marketable securities U.S. treasury securities $ 382,269 $ 67 $ (1) $ 382,335 Corporate bonds 77,009 63 (18) 77,054 Commercial paper 28,126 — — 28,126 $ 487,404 $ 130 $ (19) $ 487,515
Summary of Amortized Cost and Fair Values of Marketable Securities, by Remaining Contractual Maturity	The amortized cost and fair values of marketable securities, by remaining contractual maturity, were as follows: September 30, 2020 Amortized Fair Value (in thousands) Maturing within 1 year $ 117,196 $ 117,433
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, Cash paid for pending acquisition $ 121,433 $ — Partner referral fees 702 833 Other prepaid expenses and other current assets 15,222 11,997 $ 137,357 $ 12,830
Schedule of Other Assets	Other assets consisted of the following (in thousands): September 30, December 31, Deferred customer contract acquisition costs $ 54,791 $ 49,709 Restricted cash 261 250 Capitalized software implementation costs 2,002 1,237 Other assets 1,524 1,687 $ 58,578 $ 52,883
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities were comprised of the following (in thousands): September 30, December 31, Accrued salaries and employee benefits $ 20,769 $ 20,775 Accrued income and other taxes payable 2,919 4,198 Other accrued expenses and current liabilities 5,858 5,125 $ 29,546 $ 30,098

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table summarizes the Company’s financial assets and liabilities measured at fair value on a recurring basis by level, within the fair value hierarchy. Financial assets and financial liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement (in thousands): September 30, 2020 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 362,689 $ — $ — $ 362,689 Marketable securities U.S. treasury securities 4,510 — — 4,510 Corporate bonds — 110,335 — 110,335 Commercial paper — 2,588 — 2,588 Total assets $ 367,199 $ 112,923 $ — $ 480,122 Liabilities Contingent consideration $ — $ — $ 6,214 $ 6,214 Total liabilities $ — $ — $ 6,214 $ 6,214 December 31, 2019 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 39,767 $ — $ — $ 39,767 Marketable securities U.S. treasury securities 382,335 — — 382,335 Corporate bonds — 77,054 — 77,054 Commercial paper — 28,126 — 28,126 Total assets $ 422,102 $ 105,180 $ — $ 527,282 Liabilities Contingent consideration $ — $ — $ 6,362 $ 6,362 Total liabilities $ — $ — $ 6,362 $ 6,362
Summary of Changes in Common Stock Warrant Liability and Contingent Consideration Liability	The following table summarizes the changes in the contingent consideration liability (in thousands): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Beginning fair value $ 6,286 $ 6,500 $ 6,362 $ 6,316 Change in fair value (72) 129 (148) 313 Ending fair value $ 6,214 $ 6,629 $ 6,214 $ 6,629

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Summary of Notes	The Notes consisted of the following (in thousands): September 30, 2020 Liability: Principal $ 500,000 Unamortized debt discount and issuance costs (98,783) Net carrying amount $ 401,217 Carrying amount of the equity component $ 111,230

Equity Awards (Tables)

Equity Awards (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Expense	Stock-based compensation expense recorded in the Company’s unaudited condensed consolidated statements of operations was as follows (in thousands): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Cost of revenues $ 1,871 $ 1,431 $ 4,900 $ 3,478 Sales and marketing 5,675 4,522 15,645 11,074 Research and development 1,954 1,452 4,918 3,631 General and administrative 3,826 2,736 9,935 6,422 $ 13,326 $ 10,141 $ 35,398 $ 24,605
Summary of Stock Options Activity	The following table summarizes activity for awards that contain service-only vesting conditions (in thousands): Outstanding at December 31, 2019 3,486 Granted 578 Exercised (804) Forfeited/canceled (44) Outstanding at September 30, 2020 3,216
Summary of Restricted Stock Units Activity	The following table summarizes activity for restricted stock units (in thousands): Nonvested at December 31, 2019 1,654 Granted 1,053 Vested (533) Forfeited/canceled (85) Nonvested at September 30, 2020 2,089

Net Loss per Share - (Tables)

Net Loss per Share - (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Loss per Share	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share amounts): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net loss attributable to BlackLine, Inc. $ (8,751) $ (9,206) $ (29,926) $ (23,349) Denominator: Weighted average shares 57,063 55,480 56,619 55,164 Add: Dilutive effect of securities — — — — Shares used to calculate diluted net loss per share 57,063 55,480 56,619 55,164 Basic net loss per share attributable to BlackLine, Inc. $ (0.15) $ (0.17) $ (0.53) $ (0.42) Diluted net loss per share attributable to BlackLine, Inc. $ (0.15) $ (0.17) $ (0.53) $ (0.42)
Schedule of Potentially Dilutive Shares Excluded From Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following potentially dilutive shares were excluded from the calculation of diluted net loss per share attributable to common stockholders because they were anti-dilutive (in thousands): Nine Months Ended September 30, 2020 2019 Stock options with service-only vesting conditions 3,216 3,696 Stock options with performance conditions 483 683 Restricted stock units 2,089 1,692 Total shares excluded from net loss per share 5,788 6,071

Geographic Information (Tables)

Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Schedule of Disaggregation of Revenues by Geographic Region	The following table sets forth the Company’s revenues by geographic region (in thousands): Quarter Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 United States $ 68,058 $ 58,588 $ 192,784 $ 162,487 International 22,099 16,337 63,243 46,231 $ 90,157 $ 74,925 $ 256,027 $ 208,718

Basis of Presentation, Signif_4

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements -Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounting Policies [Abstract]
Credit losses on available-for-sale debt securities	$ 0		$ 0
Impairment charges for unrealized losses	$ 0	$ 0	$ 0	$ 0

Basis of Presentation, Signif_5

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements - Schedule of Revisions for the Financial Statement - Condensed Consolidated Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Provision for income taxes	$ 555	$ 170	$ 871	$ 856
Net loss	(7,857)	(8,876)	(26,768)	(23,434)
Net loss attributable to BlackLine, Inc.	$ (8,751)	$ (9,206)	$ (29,926)	$ (23,349)
Basic net loss per share attributable to BlackLine, Inc. (in usd per share)	$ (0.15)	$ (0.17)	$ (0.53)	$ (0.42)
Diluted net loss per share attributable to BlackLine, Inc. (in usd per share)	$ (0.15)	$ (0.17)	$ (0.53)	$ (0.42)
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Provision for income taxes		$ 206		$ 557
Net loss		(8,912)		(23,135)
Net loss attributable to BlackLine, Inc.		$ (9,242)		$ (23,050)
Basic net loss per share attributable to BlackLine, Inc. (in usd per share)		$ (0.17)		$ (0.42)
Diluted net loss per share attributable to BlackLine, Inc. (in usd per share)		$ (0.17)		$ (0.42)
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Provision for income taxes		$ (36)		$ 299
Net loss		36		(299)
Net loss attributable to BlackLine, Inc.		$ 36		$ (299)
Basic net loss per share attributable to BlackLine, Inc. (in usd per share)		$ 0		$ 0
Diluted net loss per share attributable to BlackLine, Inc. (in usd per share)		$ 0		$ 0

Basis of Presentation, Signif_6

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements - Schedule of Revisions for the Financial Statement - Condensed Consolidated Statement of Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (7,857)	$ (8,876)	$ (26,768)	$ (23,434)
Comprehensive loss	(8,188)	(8,889)	(26,512)	(22,913)
Comprehensive loss attributable to BlackLine, Inc.	$ (7,807)	(8,385)	$ (25,496)	(22,086)
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss		(8,912)		(23,135)
Comprehensive loss		(8,925)		(22,614)
Comprehensive loss attributable to BlackLine, Inc.		(8,421)		(21,787)
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss		36		(299)
Comprehensive loss		36		(299)
Comprehensive loss attributable to BlackLine, Inc.		$ 36		$ (299)

Basis of Presentation, Signif_7

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements - Schedule of Revisions for the Financial Statement - Condensed Consolidated Statements of Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 409,778	$ 324,548	$ 398,613	$ 319,267
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest	(8,751)	(9,206)	(29,926)	(23,349)
Ending Balance	416,934	393,820	416,934	393,820
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(181,853)	(146,985)	(163,598)	(132,896)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest	(7,432)	(8,367)	(25,687)	(22,456)
Ending Balance	$ (189,285)	(155,352)	$ (189,285)	(155,352)
As Previously Reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		327,185		321,569
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest		(9,242)		(23,050)
Ending Balance		396,421		396,421
As Previously Reported | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(144,348)		(130,594)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest		(8,403)		(22,157)
Ending Balance		(152,751)		(152,751)
Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(2,637)		(2,302)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest		36		(299)
Ending Balance		(2,601)		(2,601)
Adjustments | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(2,637)		(2,302)
Net loss attributable to BlackLine, Inc., including adjustment to redeemable non-controlling interest		36		(299)
Ending Balance		$ (2,601)		$ (2,601)

Basis of Presentation, Signif_8

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements - Schedule of Revisions for the Financial Statement - Condensed Consolidated Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss attributable to BlackLine, Inc.	$ (8,751)	$ (9,206)	$ (29,926)	$ (23,349)
Net loss	$ (7,857)	(8,876)	(26,768)	(23,434)
Deferred income taxes			179	737
Accrued expenses and other current liabilities			$ (1,032)	1,044
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss attributable to BlackLine, Inc.		(9,242)		(23,050)
Net loss		(8,912)		(23,135)
Deferred income taxes				35
Accrued expenses and other current liabilities				1,447
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss attributable to BlackLine, Inc.		36		(299)
Net loss		$ 36		(299)
Deferred income taxes				702
Accrued expenses and other current liabilities				$ (403)

Redeemable Non-Controlling In_3

Redeemable Non-Controlling Interest - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended					6 Months Ended	9 Months Ended		12 Months Ended
	Oct. 31, 2018	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Redeemable Noncontrolling Interest [Line Items]
Business combination, contribution								$ 121,433	$ 0
Redeemable non-controlling interest adjustment over (understatement), adjustment		$ 1,500	$ (600)	$ 1,200	$ 500	$ 400	$ 600		$ 400	$ 900
BlackLine K.K.
Redeemable Noncontrolling Interest [Line Items]
Business combination, contribution	$ 4,500
Business combination, outstanding common stock percentage	51.00%

Redeemable Non-Controlling In_4

Redeemable Non-Controlling Interest - Summary of Redeemable Non-Controlling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Redeemable Noncontrolling Interest [Roll Forward]
Balance at beginning of period	$ 7,190	$ 4,118	$ 4,905	$ 4,387
Net loss attributable to redeemable non-controlling interest (excluding adjustment to non-controlling interest)	(425)	(509)	(1,081)	(978)
Foreign currency translation	44	5	65	151
Adjustment to redeemable non-controlling interest	1,319	839	4,239	893
Balance at end of period	$ 8,128	$ 4,453	$ 8,128	$ 4,453

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Investments in Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 117,196	$ 487,404
Gross Unrealized Gains	261	130
Gross Unrealized Losses	(24)	(19)
Fair Value	117,433	487,515
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,504	382,269
Gross Unrealized Gains	6	67
Gross Unrealized Losses	0	(1)
Fair Value	4,510	382,335
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	110,104	77,009
Gross Unrealized Gains	255	63
Gross Unrealized Losses	(24)	(18)
Fair Value	110,335	77,054
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,588	28,126
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 2,588	$ 28,126

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Net gains and losses on maturities of marketable securities reclassified from accumulated other comprehensive loss to earnings		$ 100,000		$ 700,000
Realized gain and losses recognized	$ 0	$ 0	$ 100,000	$ 0
Marketable securities in continuous loss position for less than 12 months, estimated fair value	17,000,000		17,000,000		$ 83,900,000
Marketable securities in continuous loss position for greater than 12 months	0		0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	$ (300,000)		$ 300,000

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Amortized Cost and Fair Values of Marketable Securities, by Remaining Contractual Maturity (Details) $ in Thousands	Sep. 30, 2020USD ($)
Amortized Cost
Maturing within 1 year	$ 117,196
Fair Value
Maturing within 1 year	$ 117,433

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Cash paid for pending acquisition	$ 121,433	$ 0
Partner referral fees	702	833
Other prepaid expenses and other current assets	15,222	11,997
Prepaid Expense and Other Current Assets, Total	$ 137,357	$ 12,830

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Deferred customer contract acquisition costs	$ 54,791	$ 49,709
Restricted cash	261	250	$ 243
Capitalized software implementation costs	2,002	1,237
Other assets	1,524	1,687
Other Assets, Total	$ 58,578	$ 52,883

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accrued salaries and employee benefits	$ 20,769	$ 20,775
Accrued income and other taxes payable	2,919	4,198
Other accrued expenses and current liabilities	5,858	5,125
Accrued Expenses and Other Current Liabilities, Total	$ 29,546	$ 30,098

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 480,122	$ 527,282
Liabilities
Contingent consideration	6,214	6,362
Total liabilities	6,214	6,362
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	362,689	39,767
U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	4,510	382,335
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	110,335	77,054
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	2,588	28,126
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	367,199	422,102
Liabilities
Contingent consideration	0	0
Total liabilities	0	0
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	362,689	39,767
Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	4,510	382,335
Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	112,923	105,180
Liabilities
Contingent consideration	0	0
Total liabilities	0	0
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	110,335	77,054
Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	2,588	28,126
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Liabilities
Contingent consideration	6,214	6,362
Total liabilities	6,214	6,362
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 0	$ 0

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Changes in Contingent Consideration Liability (Details) - Contingent Consideration - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning fair value	$ 6,286	$ 6,500	$ 6,362	$ 6,316
Change in fair value	(72)	129	(148)	313
Ending fair value	$ 6,214	$ 6,629	$ 6,214	$ 6,629

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details) - USD ($) $ in Thousands	Aug. 13, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Proceeds form issuance of convertible note				$ 0	$ 487,163
Interest expense related to amortization of debt discount and issuance costs		$ 5,800	$ 2,900	16,874	2,923
Coupon interest expense		200		500	$ 100
Level 2
Debt Instrument [Line Items]
Estimated fair value of convertible senior notes		$ 692,800		$ 692,800
0.125% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Convertible senior notes interest rate	0.125%
Proceeds form issuance of convertible note	$ 500,000
Option to purchase aggregate principal amount	$ 65,000
Remaining life of notes				46 months

Convertible Senior Notes - Summ

Convertible Senior Notes - Summary of Notes (Details) - 0.125% Convertible Senior Notes Due 2024 $ in Thousands	Sep. 30, 2020USD ($)
Debt Instrument [Line Items]
Principal	$ 500,000
Unamortized debt discount and issuance costs	(98,783)
Net carrying amount	401,217
Carrying amount of the equity component	$ 111,230

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - BlackLine Systems, Inc. - USD ($) $ in Millions	Sep. 03, 2013	Dec. 31, 2019	Sep. 30, 2019
Business Acquisition, Contingent Consideration [Line Items]
Maximum contingent cash consideration to be distributed	$ 8
Contingent Consideration
Business Acquisition, Contingent Consideration [Line Items]
Fair value of contingent consideration		$ 6.4	$ 6.2

Equity Awards - Summary of Stoc

Equity Awards - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 13,326	$ 10,141	$ 35,398	$ 24,605
Cost of revenues
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	1,871	1,431	4,900	3,478
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	5,675	4,522	15,645	11,074
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	1,954	1,452	4,918	3,631
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 3,826	$ 2,736	$ 9,935	$ 6,422

Equity Awards - Additional Info

Equity Awards - Additional Information (Details)	Jul. 01, 2020shares	Oct. 31, 2016USD ($)Officer$ / sharesshares	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation capitalized as an asset			$ 400,000	$ 100,000	$ 900,000	$ 300,000
Stock options granted (in shares) | shares					578,000
Stock-based compensation, cost			$ 13,326,000	$ 10,141,000	$ 35,398,000	$ 24,605,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of officers, options granted | Officer		2
Officer | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares) | shares		682,800
Exercise price of options granted (in usd per share) | $ / shares		$ 14
Total fair value of awards grant		$ 24,000,000
Stock-based compensation, cost					$ 0
Awards canceled (in shares) | shares	200,000

Equity Awards - Summary of St_2

Equity Awards - Summary of Stock Options Activity (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, Beginning balance (in shares)	3,486
Granted (in shares)	578
Exercises (in shares)	(804)
Forfeitures/canceled (in shares)	(44)
Outstanding, Ending balance (in shares)	3,216

Equity Awards - Summary of Rest

Equity Awards - Summary of Restricted Stock Units Activity (Details) - Restricted stock units shares in Thousands	9 Months Ended
	Sep. 30, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested, Beginning Balance (in shares)	1,654
Grants (in shares)	1,053
Vested (in shares)	(533)
Forfeited/canceled (in shares)	(85)
Nonvested, Ending balance (in shares)	2,089

Unearned Revenue and Performa_2

Unearned Revenue and Performance Obligations - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Unearned Revenue And Performance Obligations [Abstract]
Deferred revenue recognized	$ 147,500,000	$ 117,800,000
Contracted not recognized revenue	$ 411,300,000

Unearned Revenue And Performa_3

Unearned Revenue And Performance Obligations - Remaining Performance Obligations (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Contracted not recognized revenue, expects to recognize revenue over next 12 months	59.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, expected timing of satisfaction, period	12 months

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Corporate tax rate			21.00%
Income tax expense	$ 555	$ 170	$ 871	$ 856

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Basic and Diluted Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net loss attributable to BlackLine, Inc.	$ (8,751)	$ (9,206)	$ (29,926)	$ (23,349)
Denominator:
Weighted average shares (in shares)	57,063	55,480	56,619	55,164
Add: Dilutive effect of securities (in shares)	0	0	0	0
Shares used to calculate diluted net loss per share (in shares)	57,063	55,480	56,619	55,164
Basic net loss per share attributable to BlackLine, Inc. (in usd per share)	$ (0.15)	$ (0.17)	$ (0.53)	$ (0.42)
Diluted net loss per share attributable to BlackLine, Inc. (in usd per share)	$ (0.15)	$ (0.17)	$ (0.53)	$ (0.42)

Net Loss per Share - Additional

Net Loss per Share - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to BlackLine, Inc.	$ (8,751)	$ (9,206)	$ (29,926)	$ (23,349)
Conversion option in notes not considered in calculation of diluted net loss per share (in shares)			5,788	6,071
Conversion price (in usd per share)	$ 73.40		$ 73.40
Scenario, Adjustment | Redeemable Non-Controlling Interest Adjustment
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to BlackLine, Inc.	$ (1,500)	$ (400)	$ (900)	$ (400)
Earnings (loss) per share, basic and diluted (USD per share)	$ 0.03	$ 0.01	$ 0.02	$ 0.01
Convertible Notes
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Conversion option in notes not considered in calculation of diluted net loss per share (in shares)			6,800
Convertible Notes | Certain Corporate Events Occur Prior to Maturity Date Or Company Issues Notice of Redemption
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Conversion option in notes not considered in calculation of diluted net loss per share (in shares)			9,400

Net Loss per Share - Schedule_2

Net Loss per Share - Schedule of Potentially Dilutive Shares Excluded From Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from net loss per share (in shares)	5,788	6,071
Stock options with service-only vesting conditions
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from net loss per share (in shares)	3,216	3,696
Stock options with performance conditions
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from net loss per share (in shares)	483	683
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from net loss per share (in shares)	2,089	1,692

Geographic Information - Schedu

Geographic Information - Schedule of Disaggregation of Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 90,157	$ 74,925	$ 256,027	$ 208,718
United States
Disaggregation of Revenue [Line Items]
Total revenues	68,058	58,588	192,784	162,487
International
Disaggregation of Revenue [Line Items]
Total revenues	$ 22,099	$ 16,337	$ 63,243	$ 46,231

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) shares in Thousands, $ in Thousands	Oct. 30, 2020	Oct. 02, 2020	Sep. 30, 2020	Sep. 30, 2019
Subsequent Event [Line Items]
Cash payable at close of acquisition			$ 121,433	$ 0
Restricted stock units
Subsequent Event [Line Items]
Grants (in shares)			1,053
Subsequent Event | Restricted stock units
Subsequent Event [Line Items]
Grants (in shares)	100
Subsequent Event | Rimilia
Subsequent Event [Line Items]
Business acquisition, consideration		$ 150,000
Cash payable at close of acquisition		120,000
Contingent consideration		$ 30,000
Subsequent Event | Rimilia | Restricted stock units
Subsequent Event [Line Items]
Grants (in shares)		100