Description of Business and Summary of Significant Accounting Policies	9 Months Ended
Apr. 02, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	Note 1. Description of Business and Summary of Significant Accounting Policies Description of Business Lumentum Holdings Inc. (“we”, “our” or “Lumentum”) is an industry leading provider of optical and photonic products defined by revenue and market share addressing a range of end market applications including data communications (“Datacom”) and telecommunications (“Telecom”) networking and commercial lasers (“commercial lasers”) for manufacturing, inspection and life-science applications. We are using our core optical and photonic technology and our volume manufacturing capability to expand into attractive emerging markets that benefit from advantages that optical or photonics-based solutions provide, including 3-D sensing for consumer electronics and diode light sources for a variety of consumer and industrial applications. The majority of our customers tend to be original equipment manufacturers (“OEMs”) that incorporate our products into their products which then address end-market applications. For example, we sell fiber optic components that our network equipment manufacturer (“NEM”) customers assemble into communications networking systems, which they sell to network service providers or enterprises with their own networks. Similarly, many of our customers for our Lasers products incorporate our products into tools they produce, which are used for manufacturing processes by their customers. Basis of Presentation On August 1, 2015, Lumentum became an independent publicly-traded company through the distribution by JDSU to its stockholders of 80.1% of our outstanding common stock (the “Separation”). Each JDSU stockholder of record as of the close of business on July 27, 2015 received one share of Lumentum common stock for every five shares of JDSU common stock held on the record date. JDSU was renamed Viavi and at the time of the distribution retained ownership of 19.9% of Lumentum’s outstanding shares. Lumentum was incorporated in Delaware as a wholly owned subsidiary of Viavi on February 10, 2015 and is comprised of the former communications and commercial optical products (“CCOP”) segment and WaveReady product lines of Viavi. Lumentum’s Registration Statement on Form 10 was declared effective by the U.S. Securities and Exchange Commission (“SEC”) on July 16, 2015. Lumentum’s common stock began trading “regular-way” under the ticker “LITE” on the NASDAQ stock market on August 4, 2015. On July 31, 2015, prior to the Separation, Viavi transferred substantially all of the assets and liabilities and operations of the CCOP segment and WaveReady product lines to Lumentum (the “Capitalization"). Financial statements for periods prior to the Capitalization were prepared on a stand-alone basis and were derived from Viavi’s consolidated financial statements and accounting records. For the period from June 28, 2015 to August 1, 2015, expenses were allocated to us using estimates that we consider to be a reasonable reflection of the utilization of services provided to, or benefits received by, us. The preparation of the consolidated financial statements in accordance with GAAP in the United States requires management to make estimates and assumptions that affect the amounts reported in our consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and various other assumptions believed to be reasonable. Although these estimates are based on management’s best knowledge of current events and actions that may impact the company in the future, actual results may be different from the estimates. Our critical accounting policies are those that affect our financial statements materially and involve difficult, subjective or complex judgments by management. Those policies are revenue recognition, inventory valuation, allocation methods and allocated expenses from Viavi, valuation of goodwill and other intangible assets, share-based compensation, retirement and post-retirement plan assumptions, restructuring, warranty and accounting for income taxes. See "Note 3. Related Party Transactions" in the consolidated financial statements for further information regarding the relationships we had with Viavi and other Viavi entities. Our consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC and are in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). In the opinion of management, these consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair statement of the consolidated financial statements for the periods shown. The results of operations for such periods are not necessarily indicative of the results expected for the full year or for any future periods. Fiscal Years We utilize a 52-53 week fiscal year ending on the Saturday closest to June 30th. Our fiscal 2016 is a 53-week year ending on July 2, 2016 and our third quarter of fiscal 2016 included one additional week. Our fiscal 2015 ended on June 27, 2015 and was a 52-week year. Principles of Consolidation The consolidated financial statements include certain assets and liabilities that were historically held at the Viavi level which were specifically identifiable or otherwise attributable to us. All intra-company transactions within our business were eliminated. All material transactions between us and other businesses of Viavi prior to separation were reflected as net transfers to and from Viavi as a component of financing activities in the consolidated statement of cash flows. Use of Estimates The preparation of our consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities at the date of the financial statements, the reported amount of net revenue and expenses and the disclosure of commitments and contingencies during the reporting periods. We base estimates on historical experience and on various assumptions about the future believed to be reasonable based on available information. Our reported financial position or results of operations may be materially different under changed conditions or when using different estimates and assumptions, particularly with respect to significant accounting policies. If estimates or assumptions differ from actual results, subsequent periods are adjusted to reflect more current information. Accounting Policies There have been no material changes in our significant accounting policies during the nine months ended April 2, 2016 compared to the significant accounting policies described in our Annual Report on Form 10-K/A for the fiscal year ended June 27, 2015. The accompanying unaudited interim consolidated financial statements and accompanying related notes should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K/A for the fiscal year ended June 27, 2015. Correction of Immaterial Error During the three months ended April 2, 2016, we identified an error relating to stock-based compensation expense for the three months ended December 26, 2015 in which stock-based compensation expense of $1.0 million was excluded for a specific restricted stock grant. Additionally, we identified an error relating to the overstatement of sales and use tax accrual of $0.2 million and $0.3 million for the three months ended September 26, 2015 and December 26, 2015, respectively. During the three months ended December 26, 2015, we identified an error relating to the determination of the accretion amount of Series A preferred stock for the three months ended September 26, 2015 in which the accretion of the discount related to issuance cost of $2.0 million was excluded. As a result, our net loss attributable to common stockholders and basic and diluted net loss per share attributable to common stockholders included in our quarterly report on Form 10-Q ("Form 10-Q") for the three months ended September 26, 2015 was understated by $1.8 million and $0.03 per basic and diluted share, respectively. Our net income attributable to common stockholders and basic and diluted net income per share attributable to common stockholders included in Form 10-Q for the three months ended December 26, 2015 was understated by $1.3 million and $0.02 per basic and diluted share, respectively. The correction of the errors identified in the three months ended April 2, 2016 resulted in an overstatement of net loss per share attributable to common stockholders by $0.5 million and $0.01 per basic and diluted share. We assessed the materiality of these errors and determined that the above errors were not material to our unaudited consolidated financial statements as of each of the periods mentioned above.

Note 1. Description of Business and Summary of Significant Accounting Policies

Description of Business

Lumentum Holdings Inc. (“we”, “our” or “Lumentum”) is an industry leading provider of optical and photonic products defined by revenue and market share addressing a range of end market applications including data communications (“Datacom”) and telecommunications (“Telecom”) networking and commercial lasers (“commercial lasers”) for manufacturing, inspection and life-science applications. We are using our core optical and photonic technology and our volume manufacturing capability to expand into attractive emerging markets that benefit from advantages that optical or photonics-based solutions provide, including 3-D sensing for consumer electronics and diode light sources for a variety of consumer and industrial applications. The majority of our customers tend to be original equipment manufacturers (“OEMs”) that incorporate our products into their products which then address end-market applications. For example, we sell fiber optic components that our network equipment manufacturer (“NEM”) customers assemble into communications networking systems, which they sell to network service providers or enterprises with their own networks. Similarly, many of our customers for our Lasers products incorporate our products into tools they produce, which are used for manufacturing processes by their customers.

Basis of Presentation

On August 1, 2015, Lumentum became an independent publicly-traded company through the distribution by JDSU to its stockholders of 80.1% of our outstanding common stock (the “Separation”). Each JDSU stockholder of record as of the close of business on July 27, 2015 received one share of Lumentum common stock for every five shares of JDSU common stock held on the record date. JDSU was renamed Viavi and at the time of the distribution retained ownership of 19.9% of Lumentum’s outstanding shares. Lumentum was incorporated in Delaware as a wholly owned subsidiary of Viavi on February 10, 2015 and is comprised of the former communications and commercial optical products (“CCOP”) segment and WaveReady product lines of Viavi. Lumentum’s Registration Statement on Form 10 was declared effective by the U.S. Securities and Exchange Commission (“SEC”) on July 16, 2015. Lumentum’s common stock began trading “regular-way” under the ticker “LITE” on the NASDAQ stock market on August 4, 2015.

On July 31, 2015, prior to the Separation, Viavi transferred substantially all of the assets and liabilities and operations of the CCOP segment and WaveReady product lines to Lumentum (the “Capitalization"). Financial statements for periods prior to the Capitalization were prepared on a stand-alone basis and were derived from Viavi’s consolidated financial statements and accounting records. For the period from June 28, 2015 to August 1, 2015, expenses were allocated to us using estimates that we consider to be a reasonable reflection of the utilization of services provided to, or benefits received by, us.

The preparation of the consolidated financial statements in accordance with GAAP in the United States requires management to make estimates and assumptions that affect the amounts reported in our consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and various other assumptions believed to be reasonable. Although these estimates are based on management’s best knowledge of current events and actions that may impact the company in the future, actual results may be different from the estimates. Our critical accounting policies are those that affect our financial statements materially and involve difficult, subjective or complex judgments by management. Those policies are revenue recognition, inventory valuation, allocation methods and allocated expenses from Viavi, valuation of goodwill and other intangible assets, share-based compensation, retirement and post-retirement plan assumptions, restructuring, warranty and accounting for income taxes.

See "Note 3. Related Party Transactions" in the consolidated financial statements for further information regarding the relationships we had with Viavi and other Viavi entities.

Our consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC and are in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). In the opinion of management, these consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair statement of the consolidated financial statements for the periods shown. The results of operations for such periods are not necessarily indicative of the results expected for the full year or for any future periods.

Fiscal Years

We utilize a 52-53 week fiscal year ending on the Saturday closest to June 30th. Our fiscal 2016 is a 53-week year ending on July 2, 2016 and our third quarter of fiscal 2016 included one additional week. Our fiscal 2015 ended on June 27, 2015 and was a 52-week year.

Principles of Consolidation

The consolidated financial statements include certain assets and liabilities that were historically held at the Viavi level which were specifically identifiable or otherwise attributable to us. All intra-company transactions within our business were eliminated. All material transactions between us and other businesses of Viavi prior to separation were reflected as net transfers to and from Viavi as a component of financing activities in the consolidated statement of cash flows.

Use of Estimates

The preparation of our consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities at the date of the financial statements, the reported amount of net revenue and expenses and the disclosure of commitments and contingencies during the reporting periods. We base estimates on historical experience and on various assumptions about the future believed to be reasonable based on available information. Our reported financial position or results of operations may be materially different under changed conditions or when using different estimates and assumptions, particularly with respect to significant accounting policies. If estimates or assumptions differ from actual results, subsequent periods are adjusted to reflect more current information.

Accounting Policies

There have been no material changes in our significant accounting policies during the nine months ended April 2, 2016 compared to the significant accounting policies described in our Annual Report on Form 10-K/A for the fiscal year ended June 27, 2015. The accompanying unaudited interim consolidated financial statements and accompanying related notes should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K/A for the fiscal year ended June 27, 2015.

Correction of Immaterial Error

During the three months ended April 2, 2016, we identified an error relating to stock-based compensation expense for the three months ended December 26, 2015 in which stock-based compensation expense of $1.0 million was excluded for a specific restricted stock grant. Additionally, we identified an error relating to the overstatement of sales and use tax accrual of $0.2 million and $0.3 million for the three months ended September 26, 2015 and December 26, 2015, respectively. During the three months ended December 26, 2015, we identified an error relating to the determination of the accretion amount of Series A preferred stock for the three months ended September 26, 2015 in which the accretion of the discount related to issuance cost of $2.0 million was excluded. As a result, our net loss attributable to common stockholders and basic and diluted net loss per share attributable to common stockholders included in our quarterly report on Form 10-Q ("Form 10-Q") for the three months ended September 26, 2015 was understated by $1.8 million and $0.03 per basic and diluted share, respectively. Our net income attributable to common stockholders and basic and diluted net income per share attributable to common stockholders included in Form 10-Q for the three months ended December 26, 2015 was understated by $1.3 million and $0.02 per basic and diluted share, respectively. The correction of the errors identified in the three months ended April 2, 2016 resulted in an overstatement of net loss per share attributable to common stockholders by $0.5 million and $0.01 per basic and diluted share.

We assessed the materiality of these errors and determined that the above errors were not material to our unaudited consolidated financial statements as of each of the periods mentioned above.