Income Tax	6 Months Ended
Jul. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax	Income Tax Autodesk's income tax expense was $17.6 million and $25.2 million for the three months ended July 31, 2017 and 2016, respectively, relative to a pre-tax losses of $126.4 million and $73.0 million, respectively, for the same periods. The decrease in income tax expense was primarily due to the settlement of the China audit which occurred during the three months ended July 31, 2016. Autodesk's income tax expense was $25.8 million and $39.6 million for the six months ended July 31, 2017 and 2016, respectively, relative to a pre-tax losses of $247.8 million and $226.3 million, respectively, for the same periods. The decrease in income tax expense was primarily due to the settlement of the China audit which occurred during the six months ended July 31, 2016, and the reversal of foreign withholding tax accruals during the six months ended July 31, 2017. Income tax expense consists primarily of foreign taxes, U.S. tax expense related to indefinite-lived intangibles, and withholding taxes. Autodesk regularly assesses the need for a valuation allowance against its deferred tax assets. In making that assessment, Autodesk considers both positive and negative evidence related to the likelihood of realization of the deferred tax assets to determine, based on the weight of available evidence, whether it is more likely than not that some or all of the deferred tax assets will not be realized. In evaluating the need for a valuation allowance, Autodesk considered cumulative losses in the United States arising from the Company's business model transition as a significant piece of negative evidence and established a valuation allowance against the Company’s U.S. deferred tax assets in fiscal 2016. Based on the positive and negative evidence as of July 31, 2017, the Company's valuation allowance position established for the U.S. deferred tax assets has not changed. As of July 31, 2017, the Company had $267.5 million of gross unrecognized tax benefits, excluding interest, of which approximately $253.6 million represents the amount of unrecognized tax benefits that would impact the effective tax rate, if recognized. However, this rate impact would be $32.8 million to the extent that recognition of unrecognized tax benefits currently presented as a reduction of deferred tax assets would increase the valuation allowance. It is possible that the amount of unrecognized tax benefits will change in the next twelve months; however, an estimate of the range of the possible change cannot be made at this time. The Internal Revenue Service has started an examination of the Company's U.S. consolidated federal income tax returns for fiscal years 2014 and 2015. While it is possible that the Company's tax positions may be challenged, the Company believes its positions are consistent with the tax law, and the balance sheet reflects appropriate liabilities for uncertain federal tax positions for the years being examined.

Income Tax

Autodesk's income tax expense was $17.6 million and $25.2 million for the three months ended July 31, 2017 and 2016, respectively, relative to a pre-tax losses of $126.4 million and $73.0 million, respectively, for the same periods. The decrease in income tax expense was primarily due to the settlement of the China audit which occurred during the three months ended July 31, 2016. Autodesk's income tax expense was $25.8 million and $39.6 million for the six months ended July 31, 2017 and 2016, respectively, relative to a pre-tax losses of $247.8 million and $226.3 million, respectively, for the same periods. The decrease in income tax expense was primarily due to the settlement of the China audit which occurred during the six months ended July 31, 2016, and the reversal of foreign withholding tax accruals during the six months ended July 31, 2017. Income tax expense consists primarily of foreign taxes, U.S. tax expense related to indefinite-lived intangibles, and withholding taxes.

Autodesk regularly assesses the need for a valuation allowance against its deferred tax assets. In making that assessment, Autodesk considers both positive and negative evidence related to the likelihood of realization of the deferred tax assets to determine, based on the weight of available evidence, whether it is more likely than not that some or all of the deferred tax assets will not be realized. In evaluating the need for a valuation allowance, Autodesk considered cumulative losses in the United States arising from the Company's business model transition as a significant piece of negative evidence and established a valuation allowance against the Company’s U.S. deferred tax assets in fiscal 2016. Based on the positive and negative evidence as of July 31, 2017, the Company's valuation allowance position established for the U.S. deferred tax assets has not changed.

As of July 31, 2017, the Company had $267.5 million of gross unrecognized tax benefits, excluding interest, of which approximately $253.6 million represents the amount of unrecognized tax benefits that would impact the effective tax rate, if recognized. However, this rate impact would be $32.8 million to the extent that recognition of unrecognized tax benefits currently presented as a reduction of deferred tax assets would increase the valuation allowance. It is possible that the amount of unrecognized tax benefits will change in the next twelve months; however, an estimate of the range of the possible change cannot be made at this time.

The Internal Revenue Service has started an examination of the Company's U.S. consolidated federal income tax returns for fiscal years 2014 and 2015. While it is possible that the Company's tax positions may be challenged, the Company believes its positions are consistent with the tax law, and the balance sheet reflects appropriate liabilities for uncertain federal tax positions for the years being examined.