Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	9 Months Ended
Sep. 29, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited condensed combined financial statements of Arlo that cover periods ending or as of dates prior to the completion of the IPO have been derived and carved out from the consolidated financial statements and accounting records of NETGEAR as if Arlo had operated on a stand-alone basis within the periods presented. In connection with the Separation and IPO, certain assets and liabilities presented have been transferred to Arlo at carry-over (historical cost) basis. Balances contributed by NETGEAR on or before the completion of the IPO were based on the master separation agreement between the Company and NETGEAR and related documents governing the Contribution. Following the completion of the IPO, the unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All periods presented have been accounted for in conformity with U.S. Generally Accepted Accounting Principles (“U.S. GAAP”) and pursuant to the regulations of the U.S. Securities and Exchange Commission (“SEC”).
Reclassification	Reclassification Certain reclassifications have been made to the prior year’s condensed consolidated balance sheets and statements of cash flows to conform to the current year’s presentation. The reclassifications had no effect on the prior year’s condensed consolidated statements of operations, statements of comprehensive income (loss) and statements of stockholders’ equity
Fiscal periods	Fiscal periods The Company’s fiscal year begins on January 1 of the year stated and ends on December 31 of the same year. The Company reports its results on a fiscal quarter basis rather than on a calendar quarter basis. Under the fiscal quarter basis, each of the first three fiscal quarters ends on the Sunday closest to the calendar quarter end, with the fourth quarter ending on December 31.
Use of estimates	Use of estimates The preparation of these unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Management bases its estimates on various assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Stock-based compensation	Stock-based compensation The Company’s employees have historically participated in NETGEAR’s stock-based compensation plans. Stock-based compensation expense has been allocated to the Company based on the awards and terms previously granted to the Company’s employees as well as an allocation of NETGEAR’s corporate and shared functional employee expenses. The Company measures stock-based compensation at the grant date based on the fair value of the award. The fair value of stock options and the shares offered under the employee stock purchase plan is estimated using the Black-Scholes option pricing model. Estimated compensation cost relating to restricted stock units ("RSUs") is based on the closing fair market value of NETGEAR’s common stock on the date of grant. Equity awards granted by the Company under its own stock-based compensation plans on or after the completion of the IPO are comprised of performance-based stock options (the “PSOs”), stock options, and RSUs. The Company uses the fair value method of accounting for its equity awards granted to employees and measures the cost of employee services received in exchange for the stock-based awards. The Company recognizes these compensation expense generally on a straight-line basis over the requisite service period of the award. The fair value of stock options and PSOs is estimated on the grant or offering date using the Black-Scholes option pricing model and the forfeitures recorded as they occur. The fair value of RSUs is measured on the grant date based on the closing fair market value of the Company’s common stock. The stock-based compensation cost is recognized ratably over the period during which an employee is required to provide service in exchange for the awards, usually the vesting period, which is generally four years for stock options and three to four years for RSUs. For PSOs, stock-based compensation expense of individual performance milestone is recognized over the expected performance achievement period when the achievement becomes probable. The Company's 2018 Employee Stock Purchase Plan (“ESPP”) is intended to provide employees with the opportunity to purchase the Company's common stock through accumulated payroll deductions at the end of specified purchase period. Eligible employees may contribute up to 15% of compensation, subject to certain income limits, to purchase shares of the Company's common stock. The terms of the plan include a look-back feature that enables employees to purchase stock semi-annually at a price equal to 85% of the lesser of the fair market value at the beginning of the offering period or the purchase date. The duration of each purchasing period is generally six months. The Company determines the fair value using the Black-Scholes Model using various inputs, including our estimate of expected volatility, term, dividend yield and risk-free interest rate. The Company recognizes compensation costs for the ESPP on a straight-line basis over the requisite service period of the award. The Company issued grants consisting of 50% of time-based vesting RSUs, 25% of performance-based RSUs (“PSUs”) and 25% of market-based performance RSUs (“MPSUs”) to its named executive officers (“NEOs”) during the fiscal quarter ended September 29, 2019: •The time-based vesting RSUs will vest in three equal annual installments during the period that begins on the RSU grant date. •The PSUs will vest in three equal annual installments during the period that begins on the PSU grant date based on the extent to which a revenue milestone for the fiscal year ending December 31, 2019 is achieved. •The MPSUs will vest on the three-year anniversary of the MPSU grant date based on the performance of the Company's common stock relative to the Russell 2000 Index (“the Benchmark”) during the three-year period from grant date. A positive 3.3x or negative 2.5x multiplier will be applied to the total shareholder returns (“TSR”), such that the number of shares vested will increase by 3.3% or decrease by 2.5% of the target numbers, for each 1% of positive or negative relative TSR relative to the Benchmark. In the event the Company's common stock performance is below negative 30% relative to the Benchmark, no shares will vest. In no event will the number of shares vested in each tranche exceed 200% of the target for that tranche. The estimated compensation cost relating to the PSUs, is based on the closing fair market value of the Company's stock on the date of grant. The maximum number of shares that NEOs can earn is 150% of the target number of the PSUs. The minimum number of shares that NEOs can earn is 50% of the target number of the PSUs. To estimate the compensation cost relating to the MPSUs, the Company utilized a Monte Carlo simulation model on the date of grant. The fair value determined using the Monte Carlo simulation model varies based on the assumptions used for the expected stock price volatility, the correlation coefficient between the Company and Russell 2000 Index, risk-free interest rates, and dividend yield.
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, accrued liabilities, and non-current operating lease liabilities in the unaudited condensed consolidated balance sheets. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Lease expense for lease payments are recognized in the unaudited condensed consolidated statements of operations on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments is incurred. ROU assets represent the Company’s right to use an underlying asset over the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the leases do not provide an implicit rate, the incremental borrowing rate based on the information available was used at commencement date in determining the present value of lease payments. The Company uses the implicit rate when readily determinable. The operating lease ROU asset also includes any lease payments made before the lease commencement date less any lease incentives received. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise the options. The lease agreements with lease and non-lease components are generally accounted as a single component.
Recent accounting pronouncements	Recent accounting pronouncements Emerging Growth Company Status As an emerging growth company (“EGC”), the Jumpstart Our Business Startups Act (“JOBS Act”) allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies, unless the Company otherwise irrevocably elects not to avail itself of this exemption. The Company did not make such an irrevocable election and has not delayed the adoption of any applicable accounting standards. Accounting Pronouncements Recently Adopted ASU 2016-02 In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, “Leases” (Topic 842), which requires lessees to recognize on the balance sheets a ROU asset, representing its right to use the underlying asset for the lease term, and a corresponding lease liability for all leases with terms greater than 12 months. The liability will be equal to the net present value of minimum lease payments while the ROU asset will be based on the liability, subject to adjustment, such as for initial direct costs. On January 1, 2019 (“adoption date”), the Company adopted the new standard utilizing the modified retrospective transition method through a cumulative-effect adjustment at the beginning of the first fiscal quarter of 2019. The Company has elected the package of practical expedients, which allows the Company not to reassess (1) whether an expired or existing contract as of adoption date contains a lease, (2) lease classification for any expired or existing lease as of the adoption date and (3) initial direct costs for any existing lease as of the adoption date. The Company also elected to account for each separate lease component of a contract and its associated non-lease components as a single lease component. The adoption of ASU 2016-02 resulted in the recognition of ROU assets and lease liabilities for operating leases of $14.4 million as of January 1, 2019 on its unaudited condensed consolidated balance sheets, with no material impact its unaudited consolidated statements of operations and cash flows. In addition, the Company was deemed to be the accounting owner of its build-to-suit lease arrangement for its San Jose corporate headquarters and the construction was in progress at adoption date. As such, the Company reevaluated its build-to-suit lease arrangement under ASU 2016-02 to ascertain whether it meets the criteria as the accounting owner of the build-to-suit lease arrangement through control of the underlying leased asset. The Company concluded that it did not have control over the underlying leased asset. As a result, the Company de-recognized the build to suit asset and liability as of adoption date of $21.6 million of Property and equipment and $21.9 million of financing lease obligations. The difference of $0.3 million between the de-recognized assets and the associated financing lease obligations was recorded as an adjustment to Accumulated deficit as of adoption date as mentioned above. The Company accounted for its San Jose Corporate lease arrangement as operating lease under ASU 2016-02. Consequently, as of March 31, 2019, the construction of its leasehold improvements for its San Jose corporate headquarters was partially completed and partially occupied by the Company resulting in lease commencement for the portion that was completed and occupied by the Company. Therefore, the Company proportionally recorded ROU assets and lease liabilities of $14.3 million, representing two thirds of the total value of the ROU assets and lease liabilities. As of June 30, 2019, upon the completion of the leasehold improvements and full occupation of the entire building, the Company recognized the remaining value of ROU assets and lease liabilities of $7.2 million. Refer to Note 8. Commitments and Contingencies, for further details of the impacts on the adoption. Accounting Pronouncements Not Yet Effective ASU 2016-13 In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments” (Topic 326), which replaces the incurred-loss impairment methodology and requires immediate recognition of estimated credit losses expected to occur for most financial assets, including trade receivables. Credit losses on available-for-sale debt securities with unrealized losses will be recognized as allowances for credit losses limited to the amount by which fair value is below amortized cost. ASU 2016-13 is effective for the Company beginning in the first fiscal quarter of 2021 (or the first fiscal quarter of 2020 should the Company cease to be classified as an EGC), with early adoption permitted. The Company continues to assess the potential impact of the new guidance, but does not expect it to have a material impact on its financial position, results of operations, or cash flows. With the exception of the new standards discussed above, there have been no other new accounting pronouncements that have significance, or potential significance, to the Company’s financial position, results of operations, or cash flows.
Fair Value of Financial Instruments	The Company’s investments in cash equivalents and available-for-sale securities are classified within Level 1 of the fair value hierarchy because they are valued based on quoted market prices in active markets. The Company enters into foreign currency forward contracts with only those counterparties that have long-term credit ratings of A-/A3 or higher. The Company’s foreign currency forward contracts are classified within Level 2 of the fair value hierarchy as they are valued using pricing models that take into account the contract terms as well as currency rates and counterparty credit rates. The Company verifies the reasonableness of these pricing models using observable market data for related inputs into such models. Additionally, the Company includes an adjustment for non-performance risk in the recognized measure of fair value of derivative instruments. As of September 29, 2019 and December 31, 2018, the adjustment for non-performance risk did not have a material impact on the fair value of the Company’s foreign currency forward contracts. The carrying value of non-financial assets and liabilities measured at fair value in the financial statements on a recurring basis, including accounts receivable and accounts payable, approximate fair value due to their short maturities.

Significant Accounting Policies and Recent Accounting Pronouncements (Policies)

9 Months Ended

Sep. 29, 2019

The unaudited condensed combined financial statements of Arlo that cover periods ending or as of dates prior to the completion of the IPO have been derived and carved out from the consolidated financial statements and accounting records of NETGEAR as if Arlo had operated on a stand-alone basis within the periods presented. In connection with the Separation and IPO, certain assets and liabilities presented have been transferred to Arlo at carry-over (historical cost) basis.

Balances contributed by NETGEAR on or before the completion of the IPO were based on the master separation agreement between the Company and NETGEAR and related documents governing the Contribution.

Following the completion of the IPO, the unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All periods presented have been accounted for in conformity with U.S. Generally Accepted Accounting Principles (“U.S. GAAP”) and pursuant to the regulations of the U.S. Securities and Exchange Commission (“SEC”).

Reclassification

Certain reclassifications have been made to the prior year’s condensed consolidated balance sheets and statements of cash flows to conform to the current year’s presentation. The reclassifications had no effect on the prior year’s condensed consolidated statements of operations, statements of comprehensive income (loss) and statements of stockholders’ equity

Fiscal periods

The Company’s fiscal year begins on January 1 of the year stated and ends on December 31 of the same year. The Company reports its results on a fiscal quarter basis rather than on a calendar quarter basis. Under the fiscal quarter basis, each of the first three fiscal quarters ends on the Sunday closest to the calendar quarter end, with the fourth quarter ending on December 31.

Use of estimates

The preparation of these unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Management bases its estimates on various assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.

Stock-based compensation

The Company’s employees have historically participated in NETGEAR’s stock-based compensation plans. Stock-based compensation expense has been allocated to the Company based on the awards and terms previously granted to the Company’s employees as well as an allocation of NETGEAR’s corporate and shared functional employee expenses. The Company measures stock-based compensation at the grant date based on the fair value of the award. The fair value of stock options and the shares offered under the employee stock purchase plan is estimated using the Black-Scholes option pricing model. Estimated compensation cost relating to restricted stock units ("RSUs") is based on the closing fair market value of NETGEAR’s common stock on the date of grant.

Equity awards granted by the Company under its own stock-based compensation plans on or after the completion of the IPO are comprised of performance-based stock options (the “PSOs”), stock options, and RSUs. The Company uses the fair value method of accounting for its equity awards granted to employees and measures the cost of employee services received in exchange for the stock-based awards. The Company recognizes these compensation expense generally on a straight-line basis over the requisite service period of the award. The fair value of stock options and PSOs is estimated on the grant or offering date using the Black-Scholes option pricing model and the forfeitures recorded as they occur. The fair value of RSUs is measured on the grant date based on the closing fair market value of the Company’s common stock.

The stock-based compensation cost is recognized ratably over the period during which an employee is required to provide service in exchange for the awards, usually the vesting period, which is generally four years for stock options and three to four years for RSUs. For PSOs, stock-based compensation expense of individual performance milestone is recognized over the expected performance achievement period when the achievement becomes probable.

The Company's 2018 Employee Stock Purchase Plan (“ESPP”) is intended to provide employees with the opportunity to purchase the Company's common stock through accumulated payroll deductions at the end of specified purchase period. Eligible employees may contribute up to 15% of compensation, subject to certain income limits, to purchase shares of the Company's common stock. The terms of the plan include a look-back feature that enables employees to purchase stock semi-annually at a price equal to 85% of the lesser of the fair market value at the beginning of the offering period or the purchase date. The duration of each purchasing period is generally six months. The Company determines the fair value using the Black-Scholes Model using various inputs, including our estimate of expected volatility, term, dividend yield and risk-free interest rate. The Company recognizes compensation costs for the ESPP on a straight-line basis over the requisite service period of the award.

The Company issued grants consisting of 50% of time-based vesting RSUs, 25% of performance-based RSUs (“PSUs”) and 25% of market-based performance RSUs (“MPSUs”) to its named executive officers (“NEOs”) during the fiscal quarter ended September 29, 2019:

•The time-based vesting RSUs will vest in three equal annual installments during the period that begins on the RSU grant date.

•The PSUs will vest in three equal annual installments during the period that begins on the PSU grant date based on the extent to which a revenue milestone for the fiscal year ending December 31, 2019 is achieved.

•The MPSUs will vest on the three-year anniversary of the MPSU grant date based on the performance of the Company's common stock relative to the Russell 2000 Index (“the Benchmark”) during the three-year period from grant date. A positive 3.3x or negative 2.5x multiplier will be applied to the total shareholder returns (“TSR”), such that the number of shares vested will increase by 3.3% or decrease by 2.5% of the target numbers, for each 1% of positive or negative relative TSR relative to the Benchmark. In the event the Company's common stock performance is below negative 30% relative to the Benchmark, no shares will vest. In no event will the number of shares vested in each tranche exceed 200% of the target for that tranche.

The estimated compensation cost relating to the PSUs, is based on the closing fair market value of the Company's stock on the date of grant. The maximum number of shares that NEOs can earn is 150% of the target number of the PSUs. The minimum number of shares that NEOs can earn is 50% of the target number of the PSUs.

To estimate the compensation cost relating to the MPSUs, the Company utilized a Monte Carlo simulation model on the date of grant. The fair value determined using the Monte Carlo simulation model varies based on the assumptions used for the expected stock price volatility, the correlation coefficient between the Company and Russell 2000 Index, risk-free interest rates, and dividend yield.

Leases

The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, accrued liabilities, and non-current operating lease liabilities in the unaudited condensed consolidated balance sheets. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Lease expense for lease payments are recognized in the unaudited condensed consolidated statements of operations on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments is incurred.

ROU assets represent the Company’s right to use an underlying asset over the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the leases do not provide an implicit rate, the incremental borrowing rate based on the information available was used at commencement date in determining the present value of lease payments. The Company uses the implicit rate when readily determinable. The operating lease ROU asset also includes any lease payments made before the lease commencement date less any lease incentives received. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise the options. The lease agreements with lease and non-lease components are generally accounted as a single component.

Recent accounting pronouncements

Emerging Growth Company Status

As an emerging growth company (“EGC”), the Jumpstart Our Business Startups Act (“JOBS Act”) allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies, unless the Company otherwise irrevocably elects not to avail itself of this exemption. The Company did not make such an irrevocable election and has not delayed the adoption of any applicable accounting standards.

Accounting Pronouncements Recently Adopted

ASU 2016-02

In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, “Leases” (Topic 842), which requires lessees to recognize on the balance sheets a ROU asset, representing its right to use the underlying asset for the lease term, and a corresponding lease liability for all leases with terms greater than 12 months. The liability will be equal to the net present value of minimum lease payments while the ROU asset will be based on the liability, subject to adjustment, such as for initial direct costs. On January 1, 2019 (“adoption date”), the Company adopted the new standard utilizing the modified retrospective transition method through a cumulative-effect adjustment at the beginning of the first fiscal quarter of 2019. The Company has elected the package of practical expedients, which allows the Company not to reassess (1) whether an expired or existing contract as of adoption date contains a lease, (2) lease classification for any expired or existing lease as of the adoption date and (3) initial direct costs for any existing lease as of the adoption date. The Company also elected to account for each separate lease component of a contract and its associated non-lease components as a single lease component. The adoption of ASU 2016-02 resulted in the recognition of ROU assets and lease liabilities for operating leases of $14.4 million as of January 1, 2019 on its unaudited condensed consolidated balance sheets, with no material impact its unaudited consolidated statements of operations and cash flows.

In addition, the Company was deemed to be the accounting owner of its build-to-suit lease arrangement for its San Jose corporate headquarters and the construction was in progress at adoption date. As such, the Company reevaluated its build-to-suit lease arrangement under ASU 2016-02 to ascertain whether it meets the criteria as the accounting owner of the build-to-suit lease arrangement through control of the underlying leased asset. The Company concluded that it did not have control over the underlying leased asset. As a result, the Company de-recognized the build to suit asset and liability as of adoption date of $21.6 million of Property and equipment and $21.9 million of financing lease obligations. The difference of $0.3 million between the de-recognized assets and the associated financing lease obligations was recorded as an adjustment to Accumulated deficit as of adoption date as mentioned above. The Company accounted for its San Jose Corporate lease arrangement as operating lease under ASU 2016-02. Consequently, as of March 31, 2019, the construction of its leasehold improvements for its San Jose corporate headquarters was partially completed and partially occupied by the Company resulting in lease commencement for the portion that was completed and occupied by the Company. Therefore, the Company proportionally recorded ROU assets and lease liabilities of $14.3 million, representing two thirds of the total value of the ROU assets and lease liabilities. As of June 30, 2019, upon the completion of the leasehold improvements and full occupation of the entire building, the Company recognized the remaining value of ROU assets and lease liabilities of $7.2 million. Refer to Note 8. Commitments and Contingencies, for further details of the impacts on the adoption.

Accounting Pronouncements Not Yet Effective

ASU 2016-13

In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments” (Topic 326), which replaces the incurred-loss impairment methodology and requires immediate recognition of estimated credit losses expected to occur for most financial assets, including trade receivables. Credit losses on available-for-sale debt securities with unrealized losses will be recognized as allowances for credit losses limited to the amount by which fair value is below amortized cost. ASU 2016-13 is effective for the Company beginning in the first fiscal quarter of 2021 (or the first fiscal quarter of 2020 should the Company cease to be classified as an EGC), with early adoption permitted. The Company continues to assess the potential impact of the new guidance, but does not expect it to have a material impact on its financial position, results of operations, or cash flows.

With the exception of the new standards discussed above, there have been no other new accounting pronouncements that have significance, or potential significance, to the Company’s financial position, results of operations, or cash flows.

Fair Value of Financial Instruments

The Company’s investments in cash equivalents and available-for-sale securities are classified within Level 1 of the fair value hierarchy because they are valued based on quoted market prices in active markets. The Company enters into foreign currency forward contracts with only those counterparties that have long-term credit ratings of A-/A3 or higher. The Company’s foreign currency forward contracts are classified within Level 2 of the fair value hierarchy as they are valued using pricing models that take into account the contract terms as well as currency rates and counterparty credit rates. The Company verifies the reasonableness of these pricing models using observable market data for related inputs into such models. Additionally, the Company includes an adjustment for non-performance risk in the recognized measure of fair value of derivative instruments. As of September 29, 2019 and December 31, 2018, the adjustment for non-performance risk did not have a material impact on the fair value of the Company’s foreign currency forward contracts. The carrying value of non-financial assets and liabilities measured at fair value in the financial statements on a recurring basis, including accounts receivable and accounts payable, approximate fair value due to their short maturities.