BlackLine (BL) 10-Q 9 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 03, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	BL
Entity Registrant Name	BLACKLINE, INC.
Entity Central Index Key	0001666134
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		55,046,551

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 49,676	$ 46,181
Marketable securities	85,079	86,396
Accounts receivable, net	72,343	74,902
Prepaid expenses and other current assets	12,241	14,042
Total current assets	219,339	221,521
Capitalized software development costs, net	8,969	9,023
Property and equipment, net	13,785	13,536
Intangible assets, net	24,708	27,785
Goodwill	185,138	185,138
Other assets	39,359	36,865
Total assets	504,953	493,868
Operating lease right-of-use assets	13,655
Current liabilities:
Accounts payable	4,173	3,442
Accrued expenses and other current liabilities	18,409	24,705
Deferred revenue	133,024	129,074
Short-term portion of operating lease liabilities	5,017
Short-term portion of contingent consideration	2,008	2,008
Total current liabilities	162,631	159,229
Operating lease liabilities, noncurrent	12,000
Contingent consideration	4,299	4,308
Deferred tax liabilities, net	1,116	1,116
Deferred revenue, noncurrent	196	277
Other long-term liabilities		2,982
Total liabilities	180,242	167,912
Commitments and contingencies (Note 7)
Redeemable non-controlling interest (Note 4)	4,175	4,387
Stockholders' equity:
Common stock	550	547
Additional paid-in capital	459,118	451,571
Accumulated other comprehensive income	45	45
Accumulated deficit	(139,177)	(130,594)
Total stockholders' equity	320,536	321,569
Total liabilities, redeemable non-controlling interest, and stockholders' equity	$ 504,953	$ 493,868

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Total revenues	$ 64,129	$ 51,284
Cost of revenues
Total cost of revenues	13,618	11,606
Gross profit	50,511	39,678
Operating expenses
Sales and marketing	35,848	29,227
Research and development	10,307	6,929
General and administrative	13,679	11,082
Total operating expenses	59,834	47,238
Loss from operations	(9,323)	(7,560)
Other income (expense)
Interest income	695	389
Interest expense		(4)
Other income, net	695	385
Loss before income taxes	(8,628)	(7,175)
Provision for (benefit from) income taxes	205	(20)
Net loss	(8,833)	(7,155)
Net loss attributable to non-controlling interest (Note 4)	(250)
Net loss attributable to BlackLine, Inc.	$ (8,583)	$ (7,155)
Basic net loss per share attributable to BlackLine, Inc.	$ (0.16)	$ (0.13)
Shares used to calculate basic net loss per share	54,835	53,151
Diluted net loss per share attributable to BlackLine, Inc.	$ (0.16)	$ (0.13)
Shares used to calculate diluted net loss per share	54,835	53,151
Subscription and Support
Revenues
Total revenues	$ 61,274	$ 48,625
Cost of revenues
Total cost of revenues	10,832	9,381
Professional Services
Revenues
Total revenues	2,855	2,659
Cost of revenues
Total cost of revenues	$ 2,786	$ 2,225

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (8,833)	$ (7,155)
Other comprehensive income (loss):
Net change in unrealized gains (losses) on marketable securities, net of tax of $0 for the quarters ended March 31, 2019 and 2018	94	(70)
Foreign currency translation	78
Other comprehensive income (loss)	172	(70)
Comprehensive loss	(8,661)	(7,225)
Less: Other comprehensive income attributable to redeemable non-controlling interest	(212)
Comprehensive loss attributable to BlackLine, Inc.	$ (8,449)	$ (7,225)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) (PARENTHETICAL) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net change in unrealized gain on marketable securities, tax	$ 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 at Dec. 31, 2017	$ 317,305	$ 530	$ 419,628	$ (63)	$ (102,790)
Beginning Balance, shares at Dec. 31, 2017		52,983
Stock option exercises	3,453	$ 5	3,448
Stock option exercises, shares		459
Acquisition of common stock for tax withholding obligations	(16)		(16)
Stock-based compensation	4,044		4,044
Other comprehensive income	(70)			(70)
Net loss attributable to BlackLine, Inc.	(7,155)				(7,155)
Ending Balance at Mar. 31, 2018	317,561	$ 535	427,104	(133)	(109,945)
Ending Balance, shares at Mar. 31, 2018		53,442
Beginning Balance at Dec. 31, 2018	321,569	$ 547	451,571	45	(130,594)
Beginning Balance, shares at Dec. 31, 2018		54,683
Stock option exercises	2,762	$ 1	2,761
Stock option exercises, shares		170
Vesting of restricted stock units	2	$ 2
Vesting of restricted stock units, shares		178
Acquisition of common stock for tax withholding obligations	(1,729)		(1,729)
Stock-based compensation	6,515		6,515
Net loss attributable to BlackLine, Inc.	(8,583)				(8,583)
Ending Balance at Mar. 31, 2019	$ 320,536	$ 550	$ 459,118	$ 45	$ (139,177)
Ending Balance, shares at Mar. 31, 2019		55,031

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net loss attributable to BlackLine, Inc.	$ (8,583)	$ (7,155)
Net loss attributable to redeemable non-controlling interest (Note 4)	(250)
Net loss	(8,833)	(7,155)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	5,689	5,394
Change in fair value of contingent consideration	(9)	112
Stock-based compensation	6,452	3,974
Noncash lease expense	1,245
(Accretion) amortization of purchase discounts/premiums on marketable securities, net	(409)	(67)
Net foreign currency (gains) losses	128	(59)
Deferred income taxes		(242)
Provision for (benefit from) doubtful accounts receivable	25	(51)
Changes in operating assets and liabilities:
Accounts receivable	2,333	5,058
Prepaid expenses and other current assets	1,789	(1,891)
Other assets	(2,499)	(1,285)
Accounts payable	826	(929)
Accrued expenses and other current liabilities	(6,240)	(7,935)
Deferred revenue	3,869	6,558
Operating lease liabilities	(1,340)
Other long-term liabilities		340
Net cash provided by operating activities	3,026	1,822
Cash flows from investing activities
Purchases of marketable securities	(29,975)	(30,175)
Proceeds from maturities of marketable securities	31,795	28,480
Capitalized software development costs	(1,232)	(1,653)
Purchases of property and equipment	(1,103)	(1,634)
Net cash used in investing activities	(515)	(4,982)
Cash flows from financing activities
Principal payments on capital lease obligations		(443)
Proceeds from exercises of stock options	2,764	3,453
Acquisition of common stock for tax withholding obligations	(1,729)	(16)
Net cash provided by financing activities	1,035	2,994
Effect of foreign currency exchange rate changes on cash, cash equivalents, and restricted cash	(56)
Net increase (decrease) in cash, cash equivalents, and restricted cash	3,490	(166)
Cash, cash equivalents, and restricted cash, beginning of period	46,455	31,504
Cash, cash equivalents, and restricted cash, end of period	49,945	31,338
Reconciliation of cash, cash equivalents, and restricted cash to the consolidated balance sheets
Cash and cash equivalents at end of period	49,676	30,864
Restricted cash included within prepaid expenses and other current assets at end of period		200
Restricted cash included within other assets at end of period	269	274
Total cash, cash equivalents, and restricted cash at end of period shown in the consolidated statements of cash flows	49,945	31,338
Non-cash financing and investing activities
Stock-based compensation capitalized for software development	63	70
Capitalized software development costs included in accounts payable and accrued expenses and other current liabilities at end of period	140	199
Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities at end of period	796	$ 383
Leased assets obtained in exchange for new operating lease liabilities	$ 37

Company Overview

Company Overview	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Company Overview	Note 1 – 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 New York, New York; London, the United Kingdom; Melbourne, Australia; Sydney, Australia; Paris, France; Frankfurt, Germany; Hong Kong, China; Vancouver, Canada; Ede, Netherlands; Bucharest, Romania, and Singapore

Basis of Presentation, Signific

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements	Note 2 – 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, 2018 filed with the Securities and Exchange Commission (“SEC”) on February 28, 2019. 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, 2018 was derived from audited financial statements, but does not include all disclosures required by GAAP. The operating results for the quarter ended March 31, 2019 are not necessarily indicative of the results expected for the full year ending December 31, 2019. 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. 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, 2018. On January 1, 2019, the Company adopted Accounting Standards Codification No. 842, Leases, Leases F inancial information related to periods prior to adoption will be as originally reported under ASC 840, Leases . At January 1, 2019, the Company recorded operating lease right-of-use (“ROU”) assets of $14.9 million and operating lease liabilities of $18.3 million. The difference between the leased assets and lease liabilities represents the existing deferred rent liabilities balance at adoption, resulting from historical straight-line recognition of operating leases, which was reclassified upon adoption to reduce the measurement of the leased assets. The adoption of the standard did not have an impact on the Company’s stockholders’ equity, results of operations, or cash flows. The new standard provides several optional practical expedients in transition. The Company elected the package of three practical expedients permitted under the transition guidance, which eliminates the requirement to reassess whether a contract contains a lease and lease classification. The Company has also made accounting policy elections, including a short-term lease exception policy, permitting the Company to not apply the recognition requirements of this standard to short-term leases (i.e. leases with expected terms of 12 months or less), and an accounting policy to account for lease and certain non-lease components as a single component for certain classes of assets. The portfolio approach, which allows a lessee to account for its leases at a portfolio level, was elected for certain equipment leases in which the difference in accounting for each asset separately would not have been materially different from accounting for the assets as a combined unit. The Company has leases for office space, equipment, and data centers. The Company’s leases have remaining lease terms of less than one year to five years, some of which include options to extend the leases for up to four years, and some of which include options to terminate the leases within one year. The Company determines whether an arrangement is a lease, or contains a lease, at inception if the Company is both able to identify an asset and can conclude it has the right to control the identified asset for a period of time. Leases are included in operating lease ROU assets and operating lease liabilities on the Company’s condensed consolidated balance sheets. Leases with an initial term of 12 months or less are not recorded on the condensed consolidated balance sheet. ROU assets represent the Company’s right to control an underlying asset for the lease term, and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets and operating lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company used its incremental borrowing rate based on the information available at commencement date in determining the discount rate used to present value lease payments. The Company used the incremental borrowing rate on January 1, 2019 for operating leases that commenced on or prior to that date. The incremental borrowing rate used is estimated based on what the Company would be required to pay for a collateralized loan over a similar term. Additionally, the Company used the portfolio approach when applying the discount rate selected based on the dollar amount and term of the obligation. The Company’s leases typically do not include any residual value guarantees, bargain purchase options, or asset retirement obligations. The Company’s lease terms are only for periods in which it has enforceable rights. A lease is no longer enforceable when both the lessee and the lessor each have the right to terminate the lease without permission from the other party with no more than an insignificant penalty. The Company’s lease terms are impacted by options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The Company generally uses the base, non-cancelable lease term when determining the lease assets and liabilities. The Company’s agreements may contain variable lease payments. The Company includes variable lease payments that depend on an index or a rate and excludes those which depend on facts or circumstances occurring after the commencement date, other than the passage of time. Additionally, for certain equipment leases, the Company applies a portfolio approach to effectively account for the operating lease ROU assets and operating lease liabilities. Judgment is required when determining whether any of the Company’s data center contracts contain a lease. The Company concluded a lease exists when the asset is specifically identifiable, substantially all the economic benefit of the asset is obtained, and the right to direct the use of the asset exists during the term of the lease. Recently issued accounting pronouncements not yet adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued guidance which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. This guidance amends the accounting for credit losses for available-for-sale securities and purchased financial assets with credit deterioration. This guidance is effective for annual periods beginning after December 15, 2019, and interim periods within those annual periods. Early adoption is permitted for any interim or annual period after December 15, 2018. The Company has not determined the impact of this guidance on its consolidated financial statements. In August 2018, the FASB issued guidance which aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under ASC 350-40, in order to determine which costs to capitalize and recognize as an asset. The guidance will be effective for the Company for annual reporting periods, and interim periods within those years, beginning after December 15, 2019, and can be applied either prospectively to implementation costs incurred after the date of adoption or retrospectively to all arrangements. The Company does not expect the adoption of this ASU to have a material impact on its consolidated financial statements. In August 2018, the FASB issued guidance which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement Conceptual Framework for Financial Reporting—Chapter 8: Notes to Financial Statements Recently adopted accounting pronouncements In February 2016, the FASB issued a new standard related to leases to increase transparency and comparability among organizations by requiring the recognition of ROU assets and lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company adopted this guidance effective January 1, 2019. See Note 3 – “Leases” for further details. In February 2018, the FASB issued an Accounting Standard Update (“ASU”) that provides companies with an option to reclassify stranded tax effects resulting from enactment of the Tax Cuts and Jobs Act (the "Tax Act") from accumulated other comprehensive income to retained earnings. The Company adopted this guidance effective January 1, 2019, and the adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In June 2018, the FASB issued guidance which expands the scope of Accounting Standards Codification Topic 718, Compensation—Stock Compensation

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Lessee Disclosure [Abstract]
Leases	Note 3 – Leases The following table sets forth the Company’s lease expense for the quarter ended March 31, 2019 (in thousands): Operating lease cost $ 1,513 Short-term lease cost 218 Variable cost 137 Total lease cost $ 1,868 Supplemental information related to the Company’s leases was as follows (in thousands, except percentages): Cash paid for amounts included in the measurement of lease liabilities - operating leases $ 1,527 Weighted-average remaining lease term - operating leases (in years) 3.8 Weighted-average discount rate - operating leases 6 % Maturities of lease liabilities at March 31, 2019 was (in thousands): 2019 (remaining 9 months) $ 4,591 2020 5,110 2021 3,756 2022 2,804 2023 2,647 2024 238 Total lease payments 19,146 Less imputed interest (2,129 ) Total $ 17,017 At March 31, 2019, leases entered into that have not yet commenced were immaterial and are not reflected in the table above. Future minimum lease payments under non-cancelable operating leases at December 31, 2018 was (in thousands): 2019 $ 7,059 2020 5,307 2021 3,786 2022 2,586 2023 2,638 Thereafter 237 Total $ 21,613

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interest	3 Months Ended
	Mar. 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Redeemable Non-Controlling Interest	Note 4—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 interests 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 interests’ 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 estimated redemption value of the call/put option embedded in the redeemable non-controlling interests was $0 at March 31, 2019. The following table summarizes the activity in the redeemable non-controlling interests for the period indicated below: Balance at December 31, 2018 $ 4,387 Net loss attributable to redeemable non-controlling interest (250 ) Foreign currency translation 38 Balance at March 31, 2019 $ 4,175

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Note 5 – 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: March 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Marketable securities U.S. treasury securities $ 26,195 $ 3 $ (12 ) $ 26,186 Corporate bonds 35,121 23 (9 ) 35,135 Commercial paper 23,758 — — 23,758 $ 85,074 $ 26 $ (21 ) $ 85,079 December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Marketable securities U.S. treasury securities $ 25,856 $ — $ (29 ) $ 25,827 Corporate bonds 32,030 — (60 ) 31,970 Commercial paper 28,599 — — 28,599 $ 86,485 $ — $ (89 ) $ 86,396 During the quarters ended March 31, 2019 and 2018, 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. Net gains and losses related to maturities of marketable securities that were reclassified from accumulated other comprehensive loss to earnings in the unaudited condensed consolidated statements of operations were $0.3 million for the quarter ended March 31, 2019. Net gains and losses related to maturities of marketable securities that were reclassified from accumulated other comprehensive loss to earnings in the unaudited condensed consolidated statements of operations were not material for the quarter ended March 31, 2018. Net gains and losses are determined using the specific identification method. The Company’s marketable securities have a contractual maturity of less than two years. The amortized cost and fair values of marketable securities, by remaining contractual maturity, were as follows: March 31, 2019 Amortized Cost Fair Value (in thousands) Maturing within 1 year $ 77,102 $ 77,095 Maturing between 1 and 2 years 7,972 7,984 $ 85,074 $ 85,079 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): March 31, December 31, 2019 2018 Partner referral fees $ 2,609 $ 5,219 Other prepaid expenses and other current assets 9,632 8,823 $ 12,241 $ 14,042 Other Assets Other assets consisted of the following (in thousands): March 31, December 31, 2019 2018 Deferred customer contract acquisition costs $ 37,266 $ 34,172 Restricted cash 269 274 Other assets 1,824 2,419 $ 39,359 $ 36,865 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities were comprised of the following (in thousands): March 31, December 31, 2019 2018 Accrued salaries and employee benefits $ 12,110 $ 17,054 Accrued income and other taxes payable 2,906 4,547 Short-term tenant improvement allowance — 475 Other accrued expenses and current liabilities 3,393 2,629 $ 18,409 $ 24,705

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 6 – 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): March 31, 2019 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 28,707 $ — $ — $ 28,707 Marketable securities U.S. treasury securities 26,186 — — 26,186 Corporate bonds — 35,135 — 35,135 Commercial paper — 23,758 — 23,758 Total assets $ 54,893 $ 58,893 $ — $ 113,786 Liabilities Contingent consideration $ — $ — $ 6,307 $ 6,307 Total liabilities $ — $ — $ 6,307 $ 6,307 December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 32,021 $ — $ — $ 32,021 Marketable securities U.S. treasury securities 25,827 — — 25,827 Corporate bonds — 31,970 — 31,970 Commercial paper — 28,599 — 28,599 Total assets $ 57,848 $ 60,569 $ — $ 118,417 Liabilities Contingent consideration $ — $ — $ 6,316 $ 6,316 Total liabilities $ — $ — $ 6,316 $ 6,316 The following table summarizes the changes in the contingent consideration liability (in thousands): Quarter Ended March 31, 2019 2018 Beginning fair value $ 6,316 $ 5,866 Change in fair value (9 ) 112 Ending fair value $ 6,307 $ 5,978 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.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 7 – 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 $6.3 million at March 31, 2019 and December 31, 2018 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 these indemnification arrangements. At March 31, 2019 and December 31, 2018, the Company has not accrued a liability for these indemnification arrangements because the likelihood of incurring a payment obligation, if any, in connection with these indemnification arrangements is not probable or reasonably estimable.

Equity Awards

Equity Awards	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Awards	Note 8 – 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 March 31, 2019 2018 Cost of revenues $ 888 $ 838 Sales and marketing 2,994 1,437 Research and development 944 429 General and administrative 1,626 1,270 $ 6,452 $ 3,974 For each of the quarters ended March 31, 2019 and 2018, stock-based compensation capitalized as an asset was $0.1 million. Stock options The following table summarizes activity for awards that contain service-only vesting conditions : Outstanding at December 31, 2018 3,820 Granted 73 Exercised (173 ) Forfeited/canceled (15 ) Outstanding at March 31, 2019 3,705 Restricted stock units The following table summarizes activity for restricted stock units (in thousands): Nonvested at December 31, 2018 1,300 Granted 163 Vested (212 ) Forfeited/canceled (21 ) Nonvested at March 31, 2019 1,230 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 executive officers that vest upon meeting certain performance conditions and continued service. The performance conditions include meeting yearly cash flow targets and cumulative annual recurring revenue targets through 2019. If each yearly cash flow target is met through 2019, but the full cumulative annual recurring target through 2019 is 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 and, at December 31, 2018, because each yearly target had not yet been set, no grant date for the options was established. 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 March 31, 2019, 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.

Unearned Revenue and Performanc

Unearned Revenue and Performance Obligations	3 Months Ended
	Mar. 31, 2019
Unearned Revenue And Performance Obligations [Abstract]
Unearned Revenue and Performance Obligations	Note 9 – Unearned Revenue and Performance Obligations Revenue totaling $54.9 million and $43.7 million was recognized during the quarters ended March 31, 2019 and 2018, respectively, that was previously included in the deferred revenue balance at December 31, 2018 and 2017, respectively. Contracted not recognized revenue was $297.4 million at March 31, 2019, of which the Company expects to recognize approximately 63% over the next 12 months and the remainder thereafter.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Note 10 – 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 March 31, 2019 and 2018, the Company recorded $0.2 million in income tax expense and $20,000 in income tax benefit, respectively. The increase in the income tax expense for the quarter ended March 31, 2019, compared to the quarter ended March 31, 2018, was related to an increase in tax liabilities in the Company’s foreign jurisdictions for the current period. For the quarter ended March 31, 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	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Net Loss per Share	Note 11 – 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 March 31, 2019 2018 Numerator: Net loss attributable to BlackLine, Inc. $ (8,583 ) $ (7,155 ) Denominator: Weighted average shares 54,835 53,151 Add: Dilutive effect of securities — — Shares used to calculate diluted net loss per share 54,835 53,151 Basic net loss per share attributable to BlackLine, Inc. $ (0.16 ) $ (0.13 ) Diluted net loss per share attributable to BlackLine, Inc. $ (0.16 ) $ (0.13 ) 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): March 31, 2019 2018 Stock options with service-only vesting conditions 3,705 5,017 Stock options with performance conditions 683 683 Restricted stock units 1,230 960 Total shares excluded from net loss per share 5,618 6,660

Geographic Information

Geographic Information	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Geographic Information	Note 12 – 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 March 31, 2019 2018 United States $ 50,168 $ 41,012 International 13,961 10,272 $ 64,129 $ 51,284

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Note 13 – Subsequent Events On May 8, 2019, in accordance with the Company’s Outside Director Compensation Policy, certain members of the Company’s Board of Directors were awarded restricted stock unit grants totaling approximately 19,000 shares. Each restricted stock unit entitles the recipient to receive one share of common stock upon vesting of the award. The restricted stock units will fully vest upon the earlier of the one year anniversary of the grant date or the day prior to the Company’s next annual meeting occurring after the grant date.

Basis of Presentation, Signif_2

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2019
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.
Leases	Leases F inancial information related to periods prior to adoption will be as originally reported under ASC 840, Leases . At January 1, 2019, the Company recorded operating lease right-of-use (“ROU”) assets of $14.9 million and operating lease liabilities of $18.3 million. The difference between the leased assets and lease liabilities represents the existing deferred rent liabilities balance at adoption, resulting from historical straight-line recognition of operating leases, which was reclassified upon adoption to reduce the measurement of the leased assets. The adoption of the standard did not have an impact on the Company’s stockholders’ equity, results of operations, or cash flows. The new standard provides several optional practical expedients in transition. The Company elected the package of three practical expedients permitted under the transition guidance, which eliminates the requirement to reassess whether a contract contains a lease and lease classification. The Company has also made accounting policy elections, including a short-term lease exception policy, permitting the Company to not apply the recognition requirements of this standard to short-term leases (i.e. leases with expected terms of 12 months or less), and an accounting policy to account for lease and certain non-lease components as a single component for certain classes of assets. The portfolio approach, which allows a lessee to account for its leases at a portfolio level, was elected for certain equipment leases in which the difference in accounting for each asset separately would not have been materially different from accounting for the assets as a combined unit. The Company has leases for office space, equipment, and data centers. The Company’s leases have remaining lease terms of less than one year to five years, some of which include options to extend the leases for up to four years, and some of which include options to terminate the leases within one year. The Company determines whether an arrangement is a lease, or contains a lease, at inception if the Company is both able to identify an asset and can conclude it has the right to control the identified asset for a period of time. Leases are included in operating lease ROU assets and operating lease liabilities on the Company’s condensed consolidated balance sheets. Leases with an initial term of 12 months or less are not recorded on the condensed consolidated balance sheet. ROU assets represent the Company’s right to control an underlying asset for the lease term, and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets and operating lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company used its incremental borrowing rate based on the information available at commencement date in determining the discount rate used to present value lease payments. The Company used the incremental borrowing rate on January 1, 2019 for operating leases that commenced on or prior to that date. The incremental borrowing rate used is estimated based on what the Company would be required to pay for a collateralized loan over a similar term. Additionally, the Company used the portfolio approach when applying the discount rate selected based on the dollar amount and term of the obligation. The Company’s leases typically do not include any residual value guarantees, bargain purchase options, or asset retirement obligations. The Company’s lease terms are only for periods in which it has enforceable rights. A lease is no longer enforceable when both the lessee and the lessor each have the right to terminate the lease without permission from the other party with no more than an insignificant penalty. The Company’s lease terms are impacted by options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The Company generally uses the base, non-cancelable lease term when determining the lease assets and liabilities. The Company’s agreements may contain variable lease payments. The Company includes variable lease payments that depend on an index or a rate and excludes those which depend on facts or circumstances occurring after the commencement date, other than the passage of time. Additionally, for certain equipment leases, the Company applies a portfolio approach to effectively account for the operating lease ROU assets and operating lease liabilities. Judgment is required when determining whether any of the Company’s data center contracts contain a lease. The Company concluded a lease exists when the asset is specifically identifiable, substantially all the economic benefit of the asset is obtained, and the right to direct the use of the asset exists during the term of the lease.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently issued accounting pronouncements not yet adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued guidance which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. This guidance amends the accounting for credit losses for available-for-sale securities and purchased financial assets with credit deterioration. This guidance is effective for annual periods beginning after December 15, 2019, and interim periods within those annual periods. Early adoption is permitted for any interim or annual period after December 15, 2018. The Company has not determined the impact of this guidance on its consolidated financial statements. In August 2018, the FASB issued guidance which aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under ASC 350-40, in order to determine which costs to capitalize and recognize as an asset. The guidance will be effective for the Company for annual reporting periods, and interim periods within those years, beginning after December 15, 2019, and can be applied either prospectively to implementation costs incurred after the date of adoption or retrospectively to all arrangements. The Company does not expect the adoption of this ASU to have a material impact on its consolidated financial statements. In August 2018, the FASB issued guidance which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement Conceptual Framework for Financial Reporting—Chapter 8: Notes to Financial Statements
Recently Adopted Accounting Pronouncements	Recently adopted accounting pronouncements In February 2016, the FASB issued a new standard related to leases to increase transparency and comparability among organizations by requiring the recognition of ROU assets and lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company adopted this guidance effective January 1, 2019. See Note 3 – “Leases” for further details. In February 2018, the FASB issued an Accounting Standard Update (“ASU”) that provides companies with an option to reclassify stranded tax effects resulting from enactment of the Tax Cuts and Jobs Act (the "Tax Act") from accumulated other comprehensive income to retained earnings. The Company adopted this guidance effective January 1, 2019, and the adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In June 2018, the FASB issued guidance which expands the scope of Accounting Standards Codification Topic 718, Compensation—Stock Compensation

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Lessee Disclosure [Abstract]
Summary of Lease Expense	The following table sets forth the Company’s lease expense for the quarter ended March 31, 2019 (in thousands): Operating lease cost $ 1,513 Short-term lease cost 218 Variable cost 137 Total lease cost $ 1,868
Summary of Supplemental Information Related to Leases	Supplemental information related to the Company’s leases was as follows (in thousands, except percentages): Cash paid for amounts included in the measurement of lease liabilities - operating leases $ 1,527 Weighted-average remaining lease term - operating leases (in years) 3.8 Weighted-average discount rate - operating leases 6 %
Schedule of Maturities of Lease Liabilities and Future Minimum Lease Payments Under Non-cancelable Operating Leases	Maturities of lease liabilities at March 31, 2019 was (in thousands): 2019 (remaining 9 months) $ 4,591 2020 5,110 2021 3,756 2022 2,804 2023 2,647 2024 238 Total lease payments 19,146 Less imputed interest (2,129 ) Total $ 17,017 At March 31, 2019, leases entered into that have not yet commenced were immaterial and are not reflected in the table above. Future minimum lease payments under non-cancelable operating leases at December 31, 2018 was (in thousands): 2019 $ 7,059 2020 5,307 2021 3,786 2022 2,586 2023 2,638 Thereafter 237 Total $ 21,613

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interest (Tables)	3 Months Ended
	Mar. 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Summary of Redeemable Non-Controlling Interests	The following table summarizes the activity in the redeemable non-controlling interests for the period indicated below: Balance at December 31, 2018 $ 4,387 Net loss attributable to redeemable non-controlling interest (250 ) Foreign currency translation 38 Balance at March 31, 2019 $ 4,175

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2019
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: March 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Marketable securities U.S. treasury securities $ 26,195 $ 3 $ (12 ) $ 26,186 Corporate bonds 35,121 23 (9 ) 35,135 Commercial paper 23,758 — — 23,758 $ 85,074 $ 26 $ (21 ) $ 85,079 December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Marketable securities U.S. treasury securities $ 25,856 $ — $ (29 ) $ 25,827 Corporate bonds 32,030 — (60 ) 31,970 Commercial paper 28,599 — — 28,599 $ 86,485 $ — $ (89 ) $ 86,396
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: March 31, 2019 Amortized Cost Fair Value (in thousands) Maturing within 1 year $ 77,102 $ 77,095 Maturing between 1 and 2 years 7,972 7,984 $ 85,074 $ 85,079
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): March 31, December 31, 2019 2018 Partner referral fees $ 2,609 $ 5,219 Other prepaid expenses and other current assets 9,632 8,823 $ 12,241 $ 14,042
Schedule of Other Assets	Other assets consisted of the following (in thousands): March 31, December 31, 2019 2018 Deferred customer contract acquisition costs $ 37,266 $ 34,172 Restricted cash 269 274 Other assets 1,824 2,419 $ 39,359 $ 36,865
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities were comprised of the following (in thousands): March 31, December 31, 2019 2018 Accrued salaries and employee benefits $ 12,110 $ 17,054 Accrued income and other taxes payable 2,906 4,547 Short-term tenant improvement allowance — 475 Other accrued expenses and current liabilities 3,393 2,629 $ 18,409 $ 24,705

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
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): March 31, 2019 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 28,707 $ — $ — $ 28,707 Marketable securities U.S. treasury securities 26,186 — — 26,186 Corporate bonds — 35,135 — 35,135 Commercial paper — 23,758 — 23,758 Total assets $ 54,893 $ 58,893 $ — $ 113,786 Liabilities Contingent consideration $ — $ — $ 6,307 $ 6,307 Total liabilities $ — $ — $ 6,307 $ 6,307 December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 32,021 $ — $ — $ 32,021 Marketable securities U.S. treasury securities 25,827 — — 25,827 Corporate bonds — 31,970 — 31,970 Commercial paper — 28,599 — 28,599 Total assets $ 57,848 $ 60,569 $ — $ 118,417 Liabilities Contingent consideration $ — $ — $ 6,316 $ 6,316 Total liabilities $ — $ — $ 6,316 $ 6,316
Contingent Consideration
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 March 31, 2019 2018 Beginning fair value $ 6,316 $ 5,866 Change in fair value (9 ) 112 Ending fair value $ 6,307 $ 5,978 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.

Equity Awards (Tables)

Equity Awards (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [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 March 31, 2019 2018 Cost of revenues $ 888 $ 838 Sales and marketing 2,994 1,437 Research and development 944 429 General and administrative 1,626 1,270 $ 6,452 $ 3,974
Summary of Stock Options Activity	The following table summarizes activity for awards that contain service-only vesting conditions : Outstanding at December 31, 2018 3,820 Granted 73 Exercised (173 ) Forfeited/canceled (15 ) Outstanding at March 31, 2019 3,705
Summary of Restricted Stock Units Activity	The following table summarizes activity for restricted stock units (in thousands): Nonvested at December 31, 2018 1,300 Granted 163 Vested (212 ) Forfeited/canceled (21 ) Nonvested at March 31, 2019 1,230

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 2018 Numerator: Net loss attributable to BlackLine, Inc. $ (8,583 ) $ (7,155 ) Denominator: Weighted average shares 54,835 53,151 Add: Dilutive effect of securities — — Shares used to calculate diluted net loss per share 54,835 53,151 Basic net loss per share attributable to BlackLine, Inc. $ (0.16 ) $ (0.13 ) Diluted net loss per share attributable to BlackLine, Inc. $ (0.16 ) $ (0.13 )
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): March 31, 2019 2018 Stock options with service-only vesting conditions 3,705 5,017 Stock options with performance conditions 683 683 Restricted stock units 1,230 960 Total shares excluded from net loss per share 5,618 6,660

Geographic Information (Tables)

Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 2018 United States $ 50,168 $ 41,012 International 13,961 10,272 $ 64,129 $ 51,284

Basis of Presentation, Signif_3

Basis of Presentation, Significant Accounting Policies and Recently-Issued Accounting Pronouncements - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Operating lease right-of-use (“ROU”) assets	$ 13,655	$ 14,900
Operating lease liabilities	$ 17,017	$ 18,300
Description of operating lease, option to extend	some of which include options to extend the leases for up to four years
Description of operating lease, option to terminate	some of which include options to terminate the leases within one year
Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Operating lease, remaining lease term	1 year
Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Operating lease, remaining lease term	5 years
Operating lease, extended lease term	4 years
Operating lease, termination period	1 year

Leases - Summary of Lease Expen

Leases - Summary of Lease Expense (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Lease Cost [Abstract]
Operating lease cost	$ 1,513
Short-term lease cost	218
Variable cost	137
Total lease cost	$ 1,868

Leases - Summary of Supplementa

Leases - Summary of Supplemental Information Related to Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities - operating leases	$ 1,527
Weighted-average remaining lease term - operating leases (in years)	3 years 9 months 18 days
Weighted-average discount rate - operating leases	6.00%

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities and Future Minimum Lease Payments Under Non-cancelable Operating Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease Liabilities Payments Due [Abstract]
2019 (remaining 9 months)	$ 4,591
2019			$ 7,059
2020	5,110		5,307
2021	3,756		3,786
2022	2,804		2,586
2023	2,647		2,638
2024	238
Thereafter			237
Total lease payments	19,146		$ 21,613
Less imputed interest	(2,129)
Total	$ 17,017	$ 18,300

Redeemable Non-Controlling In_3

Redeemable Non-Controlling Interest - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Oct. 31, 2018	Mar. 31, 2019
Redeemable Noncontrolling Interest [Line Items]
Redeemable non-controlling interests		$ 0
BlackLine K.K.
Redeemable Noncontrolling Interest [Line Items]
Business combination, agreement date	Sep. 30, 2018
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 Interests (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Equity Method Investments And Joint Ventures [Abstract]
Balance at December 31, 2018	$ 4,387
Net loss attributable to redeemable non-controlling interest	(250)
Foreign currency translation	38
Balance at March 31, 2019	$ 4,175

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Investments in Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 85,074	$ 86,485
Gross Unrealized Gains	26
Gross Unrealized Losses	(21)	(89)
Fair Value	85,079	86,396
U.S. treasury securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	26,195	25,856
Gross Unrealized Gains	3
Gross Unrealized Losses	(12)	(29)
Fair Value	26,186	25,827
Corporate bonds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	35,121	32,030
Gross Unrealized Gains	23
Gross Unrealized Losses	(9)	(60)
Fair Value	35,135	31,970
Commercial paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	23,758	28,599
Fair Value	$ 23,758	$ 28,599

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Realized gain and losses recognized	$ 0	$ 0
Net gains and losses on maturities of marketable securities reclassified from accumulated other comprehensive loss to earnings	$ 300,000
Maximum
Schedule Of Available For Sale Securities [Line Items]
Marketable securities contractual maturity period	2 years

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Amortized Cost and Fair Values of Marketable Securities, by Remaining Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Maturing within 1 year	$ 77,102
Maturing between 1 and 2 years	7,972
Amortized Cost	85,074	$ 86,485
Maturing within 1 year	77,095
Maturing between 1 and 2 years	7,984
Total, Fair Value	$ 85,079

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Partner referral fees	$ 2,609	$ 5,219
Other prepaid expenses and other current assets	9,632	8,823
Prepaid expenses and other current assets, Total	$ 12,241	$ 14,042

Balance Sheet Components - Su_3

Balance Sheet Components - Summary of Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Deferred customer contract acquisition costs	$ 37,266	$ 34,172
Restricted cash	269	274	$ 274
Other assets	1,824	2,419
Other Assets Noncurrent	$ 39,359	$ 36,865

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued salaries and employee benefits	$ 12,110	$ 17,054
Accrued income and other taxes payable	2,906	4,547
Short-term tenant improvement allowance		475
Other accrued expenses and current liabilities	3,393	2,629
Accrued expenses and other current liabilities	$ 18,409	$ 24,705

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	Mar. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	$ 113,786	$ 118,417
Liabilities
Contingent consideration	6,307	6,316
Total liabilities	6,307	6,316
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	28,707	32,021
U.S. treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	26,186	25,827
Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	35,135	31,970
Commercial paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	23,758	28,599
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	54,893	57,848
Level 1 | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	28,707	32,021
Level 1 | U.S. treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	26,186	25,827
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	58,893	60,569
Level 2 | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	35,135	31,970
Level 2 | Commercial paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	23,758	28,599
Level 3
Liabilities
Contingent consideration	6,307	6,316
Total liabilities	$ 6,307	$ 6,316

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Changes in Contingent Consideration Liability (Details) - Contingent Consideration - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Beginning fair value	$ 6,316	$ 5,866
Change in fair value	(9)	112
Ending fair value	$ 6,307	$ 5,978

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - BlackLine Systems, Inc. - USD ($) $ in Millions	Sep. 03, 2013	Mar. 31, 2019	Dec. 31, 2018
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		$ 6.3	$ 6.3

Equity Awards - Summary of Stoc

Equity Awards - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 6,452	$ 3,974
Cost of Revenues
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	888	838
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,994	1,437
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	944	429
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,626	$ 1,270

Equity Awards - Additional Info

Equity Awards - Additional Information (Details)	1 Months Ended	3 Months Ended
	Oct. 31, 2016USD ($)ExecutiveOfficer$ / sharesshares	Mar. 31, 2019USD ($)shares	Mar. 31, 2018USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation capitalized as an asset		$ 100,000	$ 100,000
Stock options granted to purchase shares of common stock for employee | shares		73,000
Stock-based compensation, cost		$ 6,452,000	$ 3,974,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of executive officers, options granted | ExecutiveOfficer	2
Executive Officer | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted to purchase shares of common stock for employee | shares	682,800
Exercise price of options, granted | $ / shares	$ 14
Options vesting terms		The performance conditions include meeting yearly cash flow targets and cumulative annual recurring revenue targets through 2019.
Stock-based compensation, cost		$ 0
Total fair value of awards grant	$ 24,000,000

Equity Awards - Summary of St_2

Equity Awards - Summary of Stock Options Activity (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, Beginning balance	3,820
Granted	73
Exercised	(173)
Forfeited/canceled	(15)
Outstanding, Ending balance	3,705

Equity Awards - Summary of Rest

Equity Awards - Summary of Restricted Stock Units Activity (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2019shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Restricted stock units, Nonvested, Beginning balance	1,300
Restricted stock units, Granted	163
Restricted stock units, Vested	(212)
Restricted stock units, Forfeited/canceled	(21)
Restricted stock units, Nonvested, Ending balance	1,230

Unearned Revenue and Performa_2

Unearned Revenue and Performance Obligations - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Unearned Revenue And Performance Obligations [Abstract]
Deferred revenue recognized	$ 54.9	$ 43.7
Contracted not recognized revenue	$ 297.4
Contracted not recognized revenue, expects to recognize revenue over next 12 months	63.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Corporate tax rate	21.00%
Income tax expense (benefit)	$ 205	$ (20)

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
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net loss attributable to BlackLine, Inc.	$ (8,583)	$ (7,155)
Denominator:
Weighted average shares	54,835	53,151
Shares used to calculate diluted net loss per share	54,835	53,151
Basic net loss per share attributable to BlackLine, Inc.	$ (0.16)	$ (0.13)
Diluted net loss per share attributable to BlackLine, Inc.	$ (0.16)	$ (0.13)

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	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from net loss per share	5,618	6,660
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	3,705	5,017
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	683	683
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from net loss per share	1,230	960

Geographic Information - Schedu

Geographic Information - Schedule of Disaggregation of Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Total revenues	$ 64,129	$ 51,284
United States
Disaggregation Of Revenue [Line Items]
Total revenues	50,168	41,012
International
Disaggregation Of Revenue [Line Items]
Total revenues	$ 13,961	$ 10,272

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - shares	May 08, 2019	Mar. 31, 2019
Subsequent Event [Line Items]
Restricted stock unit granted		163,000
Restricted Stock Units | Directors
Subsequent Event [Line Items]
Vesting term		The restricted stock units will fully vest upon the earlier of the one year anniversary of the grant date or the day prior to the Company’s next annual meeting occurring after the grant date.
Subsequent Event | Restricted Stock Units | Directors
Subsequent Event [Line Items]
Restricted stock unit granted	19,000
Number of common stock received upon exercise of vested award	1