Basis of Preparation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Preparation The consolidated financial statements include the accounts of Oclaro and our subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP").
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reported periods. Examples of significant estimates and assumptions made by management involve the valuation allowances for deferred tax assets, the fair value of stock-based compensation, the fair value of pension liabilities, estimates for allowances for doubtful accounts and valuation of excess and obsolete inventories. These judgments can be subjective and complex and consequently actual results could differ materially from those estimates and assumptions.
Fiscal Years	Fiscal Years We operate on a 52/53 week year ending on the Saturday closest to June 30. Our fiscal years ended June 30, 2018, July 1, 2017 and July 2, 2016 had 52 weeks, 52 weeks and 53 weeks, respectively.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all liquid investment securities with an original maturity date of three months or less to be cash equivalents. Any realized gains and losses on liquid investment securities are included in other income (expense), net in our consolidated statements of operations.
Short-term Investments	Short-Term Investments We classify short-term investments, which consist primarily of securities purchased with original maturities at date of purchase of more than three months and less than one year, as “available for sale securities.” These short-term investments are reported at market value, with the aggregate unrealized holding gains and losses reported as a component of accumulated other comprehensive income in stockholders’ equity. All realized gains and losses and unrealized losses resulting from declines in fair value that are other than temporary and not involving credit losses are recorded in the consolidated statements of operations in the period they occur.
Concentration of Credit Risks	Concentration of Credit Risks We place our cash and cash equivalents with and in the custody of financial institutions, which at times, are in excess of amounts insured. Management monitors the ongoing creditworthiness of these institutions. To date, we have not experienced significant losses on these investments.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts We perform ongoing credit evaluations of our customers and record specific allowances for doubtful accounts when a customer is unable to meet its financial obligations, as in the case of bankruptcy filings or deteriorated financial position. Estimates are used in determining allowances for customers based on factors such as current trends, the length of time the receivables are past due and historical collection experience. We write off a receivable account when all rights, remedies and recourses against the account and its principals are exhausted and record a benefit when previously reserved accounts are collected.
Inventories	Inventories Inventories, consisting of raw materials, work-in-process and finished goods are stated at the lower of cost (first in, first out basis) or market. We plan production based on orders received and a forecast demand. These production estimates are dependent on assessment of current and expected orders from our customers, including consideration that orders are subject to cancellation with limited advance notice prior to shipment. We assess the valuation of our inventory, including significant inventories held by contract manufacturers on our behalf, on a quarterly basis. Products may be unsalable because they are technically obsolete due to substitute products, specification changes or excess inventory relative to customer forecasts. We adjust the carrying value of inventory using methods that take these factors into account. If we find that the cost basis of our inventory is greater than the current market value, we write the inventory down to the estimated selling price, less the estimated costs to complete and sell the product.
Capitalized Software Costs	Capitalized Software Costs We capitalize certain development costs incurred in connection with our internal use software once an application has reached the development stage and until the software is substantially complete and ready for its intended use. These costs can include external direct costs of materials and services consumed in the project and internal costs, such as the payroll and benefits expenses attributable to those employees directly associated with the development of the software. Related maintenance and training costs are expensed as incurred. Capitalized software costs are included in property and equipment. During fiscal year 2017, we began the implementation of a new enterprise resource planning ("ERP") system. We capitalized certain costs incurred in connection with the development of this ERP system, totaling $14.4 million. We capitalized $5.0 million and $9.4 million of internal use software costs during the fiscal years ended June 30, 2018 and July 1, 2017, respectively. During the second quarter of fiscal 2018, we began using the ERP software for its intended use, and began recording depreciation expense.
Property and Equipment	Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method based upon the estimated useful lives of the assets, which generally range from three to seven years. Leasehold improvements are amortized using the straight-line method over the estimated useful lives or the term of the related lease, whichever is shorter. When assets are retired or otherwise disposed of, the assets and related accumulated depreciation are removed from the accounts. Gains or losses resulting from asset dispositions are included in (gain) loss on disposal of property and equipment in the accompanying consolidated statements of operations. Repair and maintenance costs are expensed as incurred.
Other Intangible Assets	Other Intangible Assets We review our other intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of these assets may not be recoverable. The values assigned to other intangible assets are based on estimates and judgments regarding expectations for the success and life cycle of products and technologies acquired. Our other intangible assets with definite lives are amortized over their estimated useful lives.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets We review property and equipment and certain identifiable intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of these assets is measured by comparing their carrying amounts to market prices or the future undiscounted cash flows the assets are expected to generate. If property and equipment or certain identifiable intangibles are considered to be impaired, the impairment to be recognized would equal the amount by which the carrying value of the asset exceeds its fair value based on market prices or future discounted cash flows.
Derivative Financial Instruments	Derivative Financial Instruments Our operating results are subject to fluctuations based upon changes in the exchange rates between the currencies in which we collect revenues and pay expenses. A majority of our revenues are denominated in U.S. dollars, while a portion of our expenses are denominated in United Kingdom (U.K.) pounds sterling, Japanese yen, Chinese yuan and euros, in which we pay expenses in connection with operating our facilities in the United Kingdom, Japan, China and Italy. Historically, we have entered into foreign currency forward exchange contracts in an effort to mitigate a portion of our exposure to exchange rate fluctuations between the U.S. dollar and both the U.K. pound sterling and the Japanese yen. We recognize all derivatives, such as foreign currency forward exchange contracts, on our consolidated balance sheets at fair value regardless of the purpose for holding the instrument. If the derivative is a hedge, depending on the nature of the hedge, changes in the fair value of the derivative will either be offset against the change in fair value of the hedged assets, liabilities or firm commitments through operating results or recognized in accumulated other comprehensive income until the hedged item is recognized in operating results in our consolidated statements of operations.
Warranty	Warranty We generally provide a warranty for our products ranging from 12 months to 36 months from the date of sale, although warranties for certain of our products may be longer. We accrue for the estimated costs to provide warranty services at the time revenue is recognized. Our estimate of costs to service our warranty obligations is based on historical experience and expectation of future conditions. To the extent we experience increased warranty claim activity or increased costs associated with servicing those claims, our warranty costs would increase, resulting in a decrease in gross profit.
Revenue Recognition	Revenue Recognition Our revenue consists primarily of sales of products to customers. We recognize product revenue when (i) persuasive evidence of an arrangement exists, (ii) the product has been shipped and title has transferred, (iii) collectability is reasonably assured, (iv) the fees are fixed or determinable and (v) there are no uncertainties with respect to customer acceptance.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred.
Stock-Based Compensation	Stock-Based Compensation We use grant date fair value to value restricted stock awards, restricted stock units and performance shares. We used the Black-Scholes option pricing model to value the fair value of stock options and stock appreciation rights when we last granted stock options in fiscal year 2015. We record stock-based compensation expense for time-based awards using the straight-line method over the requisite service period. Pursuant to our adoption of Accounting Standards Update ("ASC") No. 2016-09, Compensation: Improvements to Employee Share-Based Payment Accounting, in the first quarter of fiscal year 2018, we transitioned from estimating forfeitures to recording forfeitures as they occur. This change in accounting principle with regards to forfeitures was adopted using a modified retrospective approach. With the adoption of this guidance we recorded an adjustment of $0.3 million in our accumulated deficit and additional paid-in capital during the first quarter of fiscal year 2018. The amount of stock-based compensation expense recognized in any one period related to performance shares can vary based on the achievement or anticipated achievement of the performance conditions. If the performance conditions are not met or not expected to be met, no compensation cost would be recognized on the underlying performance shares, and any previously recognized compensation expense related to those performance shares would be reversed. Stock options have a term of seven to ten years and generally vest over a two to four year service period, and restricted stock awards and restricted stock units generally vest over a one to four year service period, and in certain cases each may vest earlier based upon the achievement of specific performance-based objectives as set by our Board of Directors or may be subject to additional vesting conditions based upon achievement of such performance-based objectives.
Foreign Currency Transactions and Translation Gains and Losses	Foreign Currency Transactions Gains and losses from foreign currency transactions, realized and unrealized in the event of foreign currency transactions not designated as hedges, and those transactions denominated in currencies other than our functional currency, are recorded as gain (loss) on foreign currency transactions in our consolidated statements of operations.
Income Taxes	Income Taxes We account for income taxes using an asset and liability based approach. Deferred income tax assets and liabilities are recorded based on the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates. Valuation allowances are provided against deferred income tax assets which are not likely to be realized.
Net Income (Loss) Per Share	Net Income Per Share Basic net income per share is computed using only the weighted-average number of shares of common stock outstanding for the applicable period, while diluted net income per share is computed assuming conversion of all potentially dilutive securities, such as stock options, stock appreciation rights, unvested restricted stock awards and shares issuable in connection with convertible notes during such period.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2018-05, Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118, to incorporate changes due to the TCJA being signed into law on December 22, 2017. This guidance is effective for us upon issuance. See Note 10. Income Taxes for the impact of this guidance on our financial statements and footnote disclosures. In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the TCJA. The guidance will be effective for us in the first quarter of fiscal year 2020, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In May 2017, the FASB issued ASU No. 2017-09, Compensation - Stock Compensation, to provide clarity and reduce both (i) diversity in practice and (ii) cost and complexity associated with changes to the terms or conditions of a share-based payment award. The guidance will be effective for us in the first quarter of fiscal year 2019, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In March 2017, the FASB issued ASU No. 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, changing the presentation of net periodic benefit cost in the income statement. The guidance will be effective for us in the first quarter of fiscal year 2019, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations: Clarifying the Definition of a Business, providing guidance for evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The guidance will be effective for us in the first quarter of fiscal year 2019. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows: Restricted Cash, to standardize the presentation of transfers between cash and restricted cash in the cash flow statement. Amounts described as restricted cash should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The guidance will be effective for us in the first quarter of fiscal year 2019, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory, to reduce the complexity related to the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. This guidance will be effective for us in the first quarter of fiscal year 2019, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments, to reduce the diversity in practice related to the presentation and classification of various cash flow scenarios. This guidance will be effective for us in the first quarter of fiscal year 2019, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. In May 2014 and May 2016, the FASB issued ASU 2014-09, Revenue from Contracts with Customers and ASU 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients, respectively. These updates clarify the principles for recognizing revenue and develop a common revenue standard for GAAP and International Financial Reporting Standards. The standard outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance. The guidance permits two methods of adoption, the full retrospective method applying the standard to each prior reporting period presented, or the modified retrospective method with a cumulative effect of initially applying the guidance recognized at the date of initial application. We currently plan on adopting this guidance on July 1, 2018, the start to our first quarter of fiscal year 2019, using the modified retrospective method. As a result of our assessment, we do not anticipate recording a material cumulative catch-up adjustment upon adoption of this guidance. We expect that certain of our policies, processes, footnote disclosures and customer contracts to change upon adoption of this guidance. In February 2016, the FASB issued ASU No. 2016-02, Leases, which requires recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. This guidance will be effective for us in the first quarter of fiscal year 2020, with early adoption permitted. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures.