BASIS OF PREPARATION (Policies)	9 Months Ended
BASIS OF PREPARATION (Policies)	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Oclaro, Inc., a Delaware corporation, is sometimes referred to in this Quarterly Report on Form 10-Q as “Oclaro,” “we,” “us” or “our.” The accompanying unaudited condensed consolidated financial statements of Oclaro as of March 31, 2018 and for the three and nine months ended March 31, 2018 and April 1, 2017 have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission ("SEC") Regulation S-X, and include the accounts of Oclaro and all of our subsidiaries. Accordingly, they do not include all of the information and footnotes required by such accounting principles for annual financial statements. In the opinion of management, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of our consolidated financial position and results of operations have been included. The condensed consolidated results of operations for the three and nine months ended March 31, 2018 are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year ending June 30, 2018. The condensed consolidated balance sheet as of July 1, 2017 has been derived from our audited financial statements as of such date, but does not include all disclosures required by U.S. GAAP. These unaudited condensed consolidated financial statements should be read in conjunction with our audited financial statements included in our Annual Report on Form 10-K for the year ended July 1, 2017 ("2017 Form 10-K").
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. 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 fair value of other intangible assets and long-lived assets, 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. Descriptions of the key estimates and assumptions are included in our 2017 Form 10-K.
Fiscal Years	Fiscal Years We operate on a 52/53 week year ending on the Saturday closest to June 30. Our fiscal year ending June 30, 2018 will be a 52 week year, with the quarter ended March 31, 2018 being a 13 week quarterly period. Our fiscal year ended July 1, 2017 was a 52 week year, with the quarter ended April 1, 2017 being a 13 week quarterly period.
Reclassifications	Reclassifications For presentation purposes, we have reclassified certain prior period amounts to conform to the current period financial statement presentation, including an adjustment relating to an immaterial error of approximately $8.2 million, increasing cash flows from operations associated with changes in accounts payable and increasing cash flows used in investing activities associated with purchases of property and equipment, in our condensed consolidated statement of cash flows for the nine months ended April 1, 2017. We determined that the adjustments did not have a material impact to our prior period consolidated financial statements.
Functional Currency	Functional Currency Effective October 1, 2017, the functional currency for our worldwide operations is the U.S. dollar. Prior to October 1, 2017, the functional currency for each of our foreign subsidiaries was the respective local currency for that subsidiary. The change in our functional currency is a result of significant changes in economic facts and circumstances, including (i) a re-organization of our operating environment, which includes consolidating and integrating our sales, supply chain and manufacturing organizations; (ii) a transition to centrally negotiating worldwide supplier contracts and capital expenditures in U.S. dollars; and (iii) a shift to recording all intercompany transactions in U.S. dollars. Translation adjustments reported prior to October 1, 2017, will remain as a component of accumulated other comprehensive income in our condensed consolidated balance sheet. The translated values for any non-monetary assets and liabilities as of October 1, 2017 become the new accounting basis for those assets. Effective October 1, 2017, monetary assets and liabilities denominated in currencies other than the U.S. dollar functional currency are re-measured each reporting period into U.S. dollars, with the resulting exchange gains and losses reported in gain (loss) on foreign currency transactions, net within our condensed consolidated statement of operations.
U.S. Tax Reform	U.S. Tax Reform On December 22, 2017, H.R.1, commonly referred to as the Tax Cuts and Jobs Act ("TCJA"), was signed into law. Among other things, the TCJA permanently lowers the corporate federal income tax rate to 21 percent from the existing maximum rate of 35 percent, effective for tax years including or commencing January 1, 2018. Since we operate on a 52/53 week year ending on the Saturday closest to June 30, the lower corporate income tax rate will be phased in, resulting in a U.S. statutory federal rate of approximately 28 percent for our fiscal year ending June 30, 2018, and 21 percent for subsequent fiscal years. As a result of the reduction of the corporate federal income tax rate to 21 percent, U.S. GAAP requires companies to re-value their deferred tax assets and deferred tax liabilities as of the date of enactment, with the resulting tax effects accounted for in the reporting period of enactment. We have concluded this will cause our net deferred taxes to be re-measured at the new lower tax rate. The estimated rate change impact to our net deferred tax assets is a reduction of $31.6 million. We maintain a full valuation allowance on our U.S. net deferred tax assets. Deferred tax asset re-measurement (tax expense) will be offset by a net decrease in valuation allowance, resulting in no impact on our income tax for the period ending March 31, 2018. We have not completed the revaluation calculation and will disclose any adjustments in our fiscal year-end financial statements. Additionally, TCJA introduces new international tax provisions that will be effective for our fiscal year 2019, including (i) a new provision designed to currently tax the global low-taxed income of our foreign subsidiaries known as GILTI, together with a deduction of up to 50 percent and a partial credit for foreign taxes incurred by the foreign subsidiaries; (ii) limitations on the deductibility of certain base eroding payments to foreign entities; and (iii) limitations on the use of foreign tax credits to reduce U.S. income tax liability. While each of these provisions may have an impact on our tax expense for fiscal year 2019 and future periods, we expect the tax on low-taxed income of foreign subsidiaries to have the most significant impact. Because of the complexity of the new tax on low-taxed income of foreign subsidiaries and uncertainties regarding its application in certain circumstances, we are continuing to evaluate this provision of the TCJA and its impact on our determination of the realizability of our deferred tax assets. We elected to utilize the reporting provisions of the SEC's Staff Accounting Bulletin 118 ("SAB 118"), as we did not have the necessary information available, prepared or analyzed for certain future taxable income tax effects of the TCJA in order to determine a reasonable estimate to be included as provisional amounts. We will not adjust our current or deferred taxes for those tax effects of the TCJA, for which we are unable to reasonably estimate, until a reasonable estimate can be determined.
New Accounting Standards	RECENT ACCOUNTING STANDARDS 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 1. Basis of Preparation and 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 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 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 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 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 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 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 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 2019, using the modified retrospective method with a cumulative catch up adjustment and providing additional disclosures comparing results to previous rules. We are currently evaluating the likely impact the implementation of this standard will have on our financial statements and footnote disclosures. 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 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.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.