Description of Business and Significant Accounting Policies	6 Months Ended
Oct. 28, 2016
Accounting Policies [Abstract]
Description of Business and Significant Accounting Policies	1. Description of Business and Significant Accounting Policies NetApp, Inc. (we, us, or the Company) provides software, systems and services to manage and store computer data. We enable enterprises, service providers, governmental organizations, and partners to envision, deploy and evolve their information technology environments and to reduce costs and risk while driving growth and success for their organizations. Basis of Presentation and Preparation Our fiscal year is reported on a 52- or 53-week year ending on the last Friday in April. An additional week is included in the first fiscal quarter approximately every six years to realign fiscal months with calendar months. Fiscal year 2017, ending on April 28, 2017, is a 52-week year, with 13 weeks in each of its quarters. Fiscal year 2016, which ended on April 29, 2016, was a 53-week year, with 14 weeks in its first quarter and 13 weeks in each subsequent quarter. The accompanying unaudited condensed consolidated financial statements have been prepared by the Company, and reflect all adjustments, consisting only of normal recurring adjustments, that are, in the opinion of management, necessary for the fair presentation of our financial position, results of operations, comprehensive income and cash flows for the interim periods presented. The statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information. Accordingly, these statements do not include all information and footnotes required by GAAP for annual consolidated financial statements, and should be read in conjunction with our audited consolidated financial statements as of and for the fiscal year ended April 29, 2016 contained in our Annual Report on Form 10-K. The results of operations for the three and six months ended October 28, 2016 are not necessarily indicative of the operating results to be expected for the full fiscal year or future operating periods. The preparation of the condensed consolidated financial statements in conformity with 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 reporting periods. Such estimates include, but are not limited to, revenue recognition, reserves and allowances; inventory valuation and purchase order accruals; valuation of goodwill and intangibles; restructuring reserves; product warranties; employee benefit accruals; stock-based compensation; loss contingencies; investment impairments; income taxes and fair value measurements. Actual results could differ materially from those estimates. Accounting Change – In the first quarter of fiscal 2017, we early adopted a new accounting standards update that the Financial Accounting Standards Board (FASB) issued in March 2016 that simplifies the accounting for certain aspects of stock-based payments to employees. The new standard requires that certain amendments relevant to us be applied using a modified-retrospective transition method by means of a cumulative-effect adjustment to retained earnings as of the beginning of the period in which the guidance is adopted. In connection with the adoption, we elected to account for forfeitures as they occur and the cumulative-effect impact of that change in accounting policy was a $7 million increase in retained earnings and a corresponding decrease in additional paid-in capital as of April 30, 2016. We also recorded a $3 million cumulative-effect adjustment decrease to retained earnings and a related decrease in deferred tax assets related to the forfeiture rate policy change on outstanding stock-based awards as of April 30, 2016. The standard also eliminates the requirement that excess tax benefits be realized before companies can recognize them. Accordingly, we recorded a $17 million cumulative-effect adjustment increase in retained earnings and an offsetting increase in deferred tax assets for previously unrecognized excess tax benefits as of April 30, 2016. The new standard eliminated the requirement to report excess tax benefits and certain tax deficiencies related to share-based payment transactions as additional paid-in capital. As a result, we recognized $17 million of tax deficiencies in our provision for income taxes, rather than additional paid–in capital, for the six months ended October 28, 2016. We elected to report cash flows related to excess tax benefits on a prospective basis. The presentation requirements for cash flows related to employee taxes paid for withheld shares had no impact to our statements of cash flows since such cash flows have historically been presented as a financing activity. There have been no other significant changes in our significant accounting policies as of and for the six months ended October 28, 2016, as compared to the significant accounting policies described in our Annual Report on Form 10-K for the fiscal year ended April 29, 2016.

1. Description of Business and Significant Accounting Policies

NetApp, Inc. (we, us, or the Company) provides software, systems and services to manage and store computer data. We enable enterprises, service providers, governmental organizations, and partners to envision, deploy and evolve their information technology environments and to reduce costs and risk while driving growth and success for their organizations.

Basis of Presentation and Preparation

Our fiscal year is reported on a 52- or 53-week year ending on the last Friday in April. An additional week is included in the first fiscal quarter approximately every six years to realign fiscal months with calendar months. Fiscal year 2017, ending on April 28, 2017, is a 52-week year, with 13 weeks in each of its quarters. Fiscal year 2016, which ended on April 29, 2016, was a 53-week year, with 14 weeks in its first quarter and 13 weeks in each subsequent quarter.

The accompanying unaudited condensed consolidated financial statements have been prepared by the Company, and reflect all adjustments, consisting only of normal recurring adjustments, that are, in the opinion of management, necessary for the fair presentation of our financial position, results of operations, comprehensive income and cash flows for the interim periods presented. The statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information. Accordingly, these statements do not include all information and footnotes required by GAAP for annual consolidated financial statements, and should be read in conjunction with our audited consolidated financial statements as of and for the fiscal year ended April 29, 2016 contained in our Annual Report on Form 10-K. The results of operations for the three and six months ended October 28, 2016 are not necessarily indicative of the operating results to be expected for the full fiscal year or future operating periods.

The preparation of the condensed consolidated financial statements in conformity with 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 reporting periods. Such estimates include, but are not limited to, revenue recognition, reserves and allowances; inventory valuation and purchase order accruals; valuation of goodwill and intangibles; restructuring reserves; product warranties; employee benefit accruals; stock-based compensation; loss contingencies; investment impairments; income taxes and fair value measurements. Actual results could differ materially from those estimates.

Accounting Change – In the first quarter of fiscal 2017, we early adopted a new accounting standards update that the Financial Accounting Standards Board (FASB) issued in March 2016 that simplifies the accounting for certain aspects of stock-based payments to employees. The new standard requires that certain amendments relevant to us be applied using a modified-retrospective transition method by means of a cumulative-effect adjustment to retained earnings as of the beginning of the period in which the guidance is adopted.

In connection with the adoption, we elected to account for forfeitures as they occur and the cumulative-effect impact of that change in accounting policy was a $7 million increase in retained earnings and a corresponding decrease in additional paid-in capital as of April 30, 2016. We also recorded a $3 million cumulative-effect adjustment decrease to retained earnings and a related decrease in deferred tax assets related to the forfeiture rate policy change on outstanding stock-based awards as of April 30, 2016. The standard also eliminates the requirement that excess tax benefits be realized before companies can recognize them. Accordingly, we recorded a $17 million cumulative-effect adjustment increase in retained earnings and an offsetting increase in deferred tax assets for previously unrecognized excess tax benefits as of April 30, 2016.

The new standard eliminated the requirement to report excess tax benefits and certain tax deficiencies related to share-based payment transactions as additional paid-in capital. As a result, we recognized $17 million of tax deficiencies in our provision for income taxes, rather than additional paid–in capital, for the six months ended October 28, 2016.

We elected to report cash flows related to excess tax benefits on a prospective basis. The presentation requirements for cash flows related to employee taxes paid for withheld shares had no impact to our statements of cash flows since such cash flows have historically been presented as a financing activity.

There have been no other significant changes in our significant accounting policies as of and for the six months ended October 28, 2016, as compared to the significant accounting policies described in our Annual Report on Form 10-K for the fiscal year ended April 29, 2016.