Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited Condensed Consolidated Financial Statements of Juniper Networks, Inc. (the “Company” or “Juniper”) have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“U.S. GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments, including normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the three and six months ended June 30, 2016, are not necessarily indicative of the results that may be expected for the year ending December 31, 2016, or any future period. The Condensed Consolidated Balance Sheet as of June 30, 2016, has been derived from the audited Consolidated Financial Statements for the year ended December 31, 2015 but does not include all of the information and footnotes required by GAAP for complete financial statements. The information included in this Quarterly Report on Form 10-Q (“Report”) should be read in conjunction with “Management's Discussion and Analysis of Financial Condition and Results of Operations,” “Risk Factors,” “Quantitative and Qualitative Disclosures About Market Risk,” and the Consolidated Financial Statements and footnotes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2015.
Recent accounting pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board ("FASB") issued ASU No. 2016-13 (Topic 326) Financial Instruments - Credit Losses. The pronouncement was issued to provide more decision-useful information about the expected credit losses on financial instruments and changes the loss impairment methodology. This pronouncement is effective for reporting periods beginning after December 15, 2019, and interim periods within those fiscal years, using a modified retrospective adoption method. A prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures. In March 2016, the FASB issued ASU No. 2016-09 (Topic 718) Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"), which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, forfeiture, statutory tax withholding requirements, and classification on the statement of cash flows. ASU-2016-09 is effective for interim and annual reporting periods beginning after December 15, 2016. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures. In March 2016, the FASB issued ASU No. 2016-07 (Topic 323) Investments—Equity Method and Joint Ventures: Simplifying the Transition to the Equity Method of Accounting ("ASU 2016-07"), which eliminates the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. This update requires that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. This update requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive loss at the date the investment becomes qualified for use of the equity method. ASU 2016-07 is effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures. In March 2016, the FASB issued ASU No. 2016-06 (Topic 815) Derivatives and Hedging: Contingent Put and Call Options in Debt Instruments ("ASU 2016-06"), which requires that embedded derivatives be separated from the host contract and accounted for separately as derivatives if certain criteria are met. One of those criteria is that the economic characteristics and risks of the embedded derivatives are not clearly and closely related to the economic characteristics and risks of the host contract (the “clearly and closely related” criterion). In addition, in March 2016, the FASB issued ASU No. 2016-05 (Topic 815), Derivatives and Hedging: Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships, ("ASU 2016-05"), which clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. ASU 2016-06 and ASU 2016-05 are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures. In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases ("ASU 2016-02"), which requires recognition of lease assets and lease liabilities on the balance sheet by the lessees for lease contracts with a lease term of more than twelve months. ASU 2016-02 should be applied on a modified retrospective basis and is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"), which requires equity investments to be measured at fair value with changes in fair value recognized in net income and simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. Entities may choose a practical expedient, to estimate the fair value of certain equity securities that do not have readily determinable fair value. If the practical expedient is elected, these investments would be recorded at cost, less impairment and subsequently adjusted for observable price changes. The guidance also updates certain presentation and disclosure requirements. ASU 2016-01 is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is not permitted. The Company is currently evaluating the impact that ASU 2016-01will have on its Consolidated Financial Statements and disclosures. In July 2015, the FASB issued ASU No. 2015-11 (Subtopic 330) - Simplifying the Measurement of Inventory ("ASU 2015-11"), which provides guidance to companies who account for inventory using either the first-in, first-out ("FIFO") or average cost methods. The guidance states that companies should measure inventory at the lower of cost and net realizable value. Net realizable value is defined as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. ASU 2015-11 is effective for fiscal years beginning after December 15, 2016. Early adoption is permitted. The adoption of this standard will not have a significant impact on the Company's Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09 (Topic 606)—Revenue from Contracts with Customers (“ASU 2014-09”) which provides guidance for revenue recognition. This ASU affects all contracts that the Company enters into with customers to transfer goods and services or for the transfer of nonfinancial assets. This ASU will supersede the revenue recognition requirements in Topic 605, and most industry specific guidance. This ASU also supersedes some cost guidance included in Subtopic 605-35, Revenue Recognition-Construction-Type and Production-Type Contracts. The standard's core principle is that revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. In doing so, the Company will need to use additional judgment and estimates than under the existing guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In August 2015, the FASB issued ASU 2015-14 which deferred the effective date of the new revenue standard from December 15, 2016 to December 15, 2017, with early adoption permitted as of annual reporting periods beginning after December 15, 2016. Accordingly, the ASU will be effective for the Company beginning fiscal year 2018. In addition, in March 2016, the FASB issued ASU No. 2016-08 (Topic 606) Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net) (“ASU 2016-08”), which clarifies the principal-versus-agent guidance in Topic 606 and requires an entity to determine whether the nature of its promise to provide goods or services to a customer is performed in a principal or agent capacity and to recognize revenue in a gross or net manner based on its principal/agent designation. In April 2016, the FASB also issued ASU No. 2016-10 (Topic 606) Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing (“ASU 2016-10”), which amends the revenue guidance on identifying performance obligations and accounting for licenses of intellectual property. In May 2016, the FASB also issued ASU No. 2016-12 (Topic 606) Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients (“ASU 2016-12”), which amends the revenue guidance to clarify measurement and presentation as well as to include some practical expedients and policy elections. There are two transition methods available under the new standard, either cumulative effect or retrospective. ASU 2016-08, ASU 2016-10, and ASU 2016-12 must be adopted concurrently with the adoption of ASU 2014-09. The Company is currently evaluating the impact of the adoption of this standard on its Consolidated Financial Statements and disclosures.

Recent Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board ("FASB") issued ASU No. 2016-13 (Topic 326) Financial Instruments - Credit Losses. The pronouncement was issued to provide more decision-useful information about the expected credit losses on financial instruments and changes the loss impairment methodology. This pronouncement is effective for reporting periods beginning after December 15, 2019, and interim periods within those fiscal years, using a modified retrospective adoption method. A prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures.

In March 2016, the FASB issued ASU No. 2016-09 (Topic 718) Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"), which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, forfeiture, statutory tax withholding requirements, and classification on the statement of cash flows. ASU-2016-09 is effective for interim and annual reporting periods beginning after December 15, 2016. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures.

In March 2016, the FASB issued ASU No. 2016-07 (Topic 323) Investments—Equity Method and Joint Ventures: Simplifying the Transition to the Equity Method of Accounting ("ASU 2016-07"), which eliminates the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. This update requires that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. This update requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive loss at the date the investment becomes qualified for use of the equity method. ASU 2016-07 is effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures.

In March 2016, the FASB issued ASU No. 2016-06 (Topic 815) Derivatives and Hedging: Contingent Put and Call Options in Debt Instruments ("ASU 2016-06"), which requires that embedded derivatives be separated from the host contract and accounted for separately as derivatives if certain criteria are met. One of those criteria is that the economic characteristics and risks of the embedded derivatives are not clearly and closely related to the economic characteristics and risks of the host contract (the “clearly and closely related” criterion). In addition, in March 2016, the FASB issued ASU No. 2016-05 (Topic 815), Derivatives and Hedging: Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships, ("ASU 2016-05"), which clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. ASU 2016-06 and ASU 2016-05 are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures.

In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases ("ASU 2016-02"), which requires recognition of lease assets and lease liabilities on the balance sheet by the lessees for lease contracts with a lease term of more than twelve months. ASU 2016-02 should be applied on a modified retrospective basis and is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements and disclosures.

In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"), which requires equity investments to be measured at fair value with changes in fair value recognized in net income and simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. Entities may choose a practical expedient, to estimate the fair value of certain equity securities that do not have readily determinable fair value. If the practical expedient is elected, these investments would be recorded at cost, less impairment and subsequently adjusted for observable price changes. The guidance also updates certain presentation and disclosure requirements. ASU 2016-01 is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is not permitted. The Company is currently evaluating the impact that ASU 2016-01will have on its Consolidated Financial Statements and disclosures.

In July 2015, the FASB issued ASU No. 2015-11 (Subtopic 330) - Simplifying the Measurement of Inventory ("ASU 2015-11"), which provides guidance to companies who account for inventory using either the first-in, first-out ("FIFO") or average cost methods. The guidance states that companies should measure inventory at the lower of cost and net realizable value. Net realizable value is defined as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. ASU 2015-11 is effective for fiscal years beginning after December 15, 2016. Early adoption is permitted. The adoption of this standard will not have a significant impact on the Company's Consolidated Financial Statements.

In May 2014, the FASB issued ASU No. 2014-09 (Topic 606)—Revenue from Contracts with Customers (“ASU 2014-09”) which provides guidance for revenue recognition. This ASU affects all contracts that the Company enters into with customers to transfer goods and services or for the transfer of nonfinancial assets. This ASU will supersede the revenue recognition requirements in Topic 605, and most industry specific guidance. This ASU also supersedes some cost guidance included in Subtopic 605-35, Revenue Recognition-Construction-Type and Production-Type Contracts. The standard's core principle is that revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. In doing so, the Company will need to use additional judgment and estimates than under the existing guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In August 2015, the FASB issued ASU 2015-14 which deferred the effective date of the new revenue standard from December 15, 2016 to December 15, 2017, with early adoption permitted as of annual reporting periods beginning after December 15, 2016. Accordingly, the ASU will be effective for the Company beginning fiscal year 2018. In addition, in March 2016, the FASB issued ASU No. 2016-08 (Topic 606) Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net) (“ASU 2016-08”), which clarifies the principal-versus-agent guidance in Topic 606 and requires an entity to determine whether the nature of its promise to provide goods or services to a customer is performed in a principal or agent capacity and to recognize revenue in a gross or net manner based on its principal/agent designation. In April 2016, the FASB also issued ASU No. 2016-10 (Topic 606) Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing (“ASU 2016-10”), which amends the revenue guidance on identifying performance obligations and accounting for licenses of intellectual property. In May 2016, the FASB also issued ASU No. 2016-12 (Topic 606) Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients (“ASU 2016-12”), which amends the revenue guidance to clarify measurement and presentation as well as to include some practical expedients and policy elections. There are two transition methods available under the new standard, either cumulative effect or retrospective. ASU 2016-08, ASU 2016-10, and ASU 2016-12 must be adopted concurrently with the adoption of ASU 2014-09. The Company is currently evaluating the impact of the adoption of this standard on its Consolidated Financial Statements and disclosures.