Income Taxes (Notes)	9 Months Ended
Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes reflects tax on foreign earnings and federal and state tax on U.S. earnings. The Company had an effective tax rate of 227.7% for the three months ended December 31, 2017 and a negative effective tax rate of 28.5% for the three months ended December 31, 2016. The Company had an effective tax rate of 80.2% for the nine months ended December 31, 2017 and a negative effective tax rate of 87.3% for the nine months ended December 31, 2016. On December 22, 2017, the Tax Cuts and Jobs Act (the "Act") was enacted into law. The Act provides for numerous significant tax law changes and modifications including the reduction of the U.S. federal corporate income tax rate from 35.0% to 21.0%, the requirement for companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and the creation of new taxes on certain foreign-sourced earnings. As a fiscal year-end taxpayer, certain provisions of the Act began to impact the Company in the third quarter of fiscal 2018, while other provisions will impact the Company beginning in fiscal 2019. The corporate tax rate reduction is effective as of January 1, 2018. Since the Company has a fiscal year rather than a calendar year, it is subject to rules relating to transitional tax rates. As a result, the Company’s fiscal 2018 federal statutory rate will be a blended rate of 31.5%. The change in the statutory tax rate from 35.0% to 31.5% for the Company's fiscal 2018 does not have a significant impact on the Company's effective tax rate. Accounting Standards Codification ("ASC") 740, Income Taxes, requires companies to recognize the effect of the tax law changes in the period of enactment. However, the SEC staff issued Staff Accounting Bulletin ("SAB") 118 which allows companies to record provisional amounts during a measurement period that is similar to the measurement period used when accounting for business combinations. The Company has recorded a reasonable estimate when possible and with the understanding that the provisional amount is subject to further adjustments under SAB 118. In addition, for significant items for which the Company could not make a reasonable estimate, no provisional amounts were recorded. Amounts will be recorded during the measurement period allowed under SAB 118 when a reasonable estimate can be made, or when the effect of the Act is known. As of December 31, 2017, the Company made a reasonable estimate of the effects on its existing deferred tax balances and the one-time transition tax. The Company recognized a provisional amount of $443.2 million, which decreased diluted net income per common share by $1.79 for the nine months ended December 31, 2017, and which was included as a component of income tax expense from continuing operations. The Company will continue to refine provisional balances and adjustments may be made under SAB 118 during the measurement period as a result of future changes in interpretation, information available, assumptions made by the Company and/or issuance of additional guidance and these adjustments could be material. The one-time transition tax is based on the Company's total post-1986 earnings and profits ("E&P") of its foreign subsidiaries. Substantially all of the Company's E&P were permanently reinvested outside the U.S prior to the Act. The Company recorded provisional U.S. amounts for its one-time transition tax liabilities, resulting in an increase in income tax expense of $627.7 million. In addition, the Company released the deferred tax liabilities related to non-permanently reinvested E&P, resulting in a decrease in income tax expense of $5.5 million. The net increase to tax expense is $622.2 million. The one-time transition tax may be elected to be paid over a period of eight years. The Company intends to make this election. The Company has not yet completed its calculation of the total post-1986 E&P for its foreign subsidiaries. In addition, the one-time transition tax is based in part on the amount of those earnings held in cash and other specified assets either as of the end of fiscal 2018 or the average of the year-end balances for fiscal 2016 and fiscal 2017. The Company's calculation of this amount will change with further analysis, fourth quarter activities, and further guidance from the U.S. federal and state tax authorities about the application of these new rules. The Company will continue to evaluate the impact of the tax law change as it relates to the accounting for the outside basis difference of its foreign entities. As a result of the reduction of the corporate income tax rate to 21.0%, U.S. GAAP requires companies to remeasure their deferred tax assets and liabilities as of the date of enactment, with resulting tax effects accounted for in the reporting period of enactment. The Company remeasured deferred tax assets and liabilities based on the rates at which they are expected to to be utilized in the future. The provisional amount recorded for the remeasurement and resulting income tax benefit of the Company's deferred tax balance was $142.6 million. The Company's actual income tax benefit may vary materially from the provisional amount because the final analysis will be based on balances as of March 31, 2018. Due to the Act, the Company released its valuation allowance on foreign tax credits during the three months ended December 31, 2017. The provisional amount recorded for the valuation allowance release was an income tax benefit of $36.4 million. The Company is still evaluating how the Act impacts the valuation allowance on state net operating loss carryforwards and state tax credits, and the Company may report an adjustment to the valuation allowances in accordance with SAB 118 in subsequent quarters. The Company's effective tax rate for the three and nine months ended December 31, 2017 is higher compared to the prior year primarily due to the one-time transition tax net of the reversal of the related deferred tax liabilities. The Company's effective tax rate is different than statutory rates in the U.S. due primarily to the one-time transition tax net of the reversal of the related deferred tax liabilities, as well as its mix of earnings in foreign jurisdictions with lower tax rates as well as numerous tax holidays it receives related to its Thailand manufacturing operations based on its investment in property, plant and equipment in Thailand. The Company's tax holiday periods in Thailand expire at various times in the future, however, the Company actively seeks to obtain new tax holidays. The Company does not expect the future expiration of any of its tax holiday periods in Thailand to have a material impact on its effected tax rate. The material components of foreign income taxed at a rate lower than the U.S. are earnings accrued in Thailand and Ireland, and earnings accrued by the Company's offshore technology company which is resident in the Cayman Islands. The Company files U.S. federal, U.S. state, and foreign income tax returns. For U.S. federal, and in general for U.S. state tax returns, the fiscal 2005 and later tax years remain effectively open for examination by tax authorities. For foreign tax returns, the Company is generally no longer subject to income tax examinations for years prior to fiscal 2007. The Company recognizes liabilities for anticipated tax audit issues in the U.S. and other domestic and international tax jurisdictions based on its estimate of whether, and the extent to which, additional tax payments are more likely than not. The Company believes that it has appropriate support for the income tax positions taken and to be taken on its tax returns and that its accruals for tax liabilities are adequate for all open years based on an assessment of many factors including past experience and interpretations of tax laws applied to the facts of each matter. The Company believes it maintains appropriate reserves to offset any potential income tax liabilities that may arise upon final resolution of matters for open tax years. If such reserve amounts ultimately prove to be unnecessary, the resulting reversal of such reserves would result in tax benefits being recorded in the period the reserves are no longer deemed necessary. If such amounts prove to be less than an ultimate assessment, a future charge to expense would be recorded in the period in which the assessment is determined. Although the timing of the resolution or closure of audits is highly uncertain, the Company does not believe it is reasonably possible that the unrecognized tax benefits would materially change in the next 12 months.

Income Taxes

The provision for income taxes reflects tax on foreign earnings and federal and state tax on U.S. earnings. The Company had an effective tax rate of 227.7% for the three months ended December 31, 2017 and a negative effective tax rate of 28.5% for the three months ended December 31, 2016. The Company had an effective tax rate of 80.2% for the nine months ended December 31, 2017 and a negative effective tax rate of 87.3% for the nine months ended December 31, 2016.

On December 22, 2017, the Tax Cuts and Jobs Act (the "Act") was enacted into law. The Act provides for numerous significant tax law changes and modifications including the reduction of the U.S. federal corporate income tax rate from 35.0% to 21.0%, the requirement for companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and the creation of new taxes on certain foreign-sourced earnings. As a fiscal year-end taxpayer, certain provisions of the Act began to impact the Company in the third quarter of fiscal 2018, while other provisions will impact the Company beginning in fiscal 2019.

The corporate tax rate reduction is effective as of January 1, 2018. Since the Company has a fiscal year rather than a calendar year, it is subject to rules relating to transitional tax rates. As a result, the Company’s fiscal 2018 federal statutory rate will be a blended rate of 31.5%. The change in the statutory tax rate from 35.0% to 31.5% for the Company's fiscal 2018 does not have a significant impact on the Company's effective tax rate.

Accounting Standards Codification ("ASC") 740, Income Taxes, requires companies to recognize the effect of the tax law changes in the period of enactment. However, the SEC staff issued Staff Accounting Bulletin ("SAB") 118 which allows companies to record provisional amounts during a measurement period that is similar to the measurement period used when accounting for business combinations. The Company has recorded a reasonable estimate when possible and with the understanding that the provisional amount is subject to further adjustments under SAB 118. In addition, for significant items for which the Company could not make a reasonable estimate, no provisional amounts were recorded. Amounts will be recorded during the measurement period allowed under SAB 118 when a reasonable estimate can be made, or when the effect of the Act is known. As of December 31, 2017, the Company made a reasonable estimate of the effects on its existing deferred tax balances and the one-time transition tax. The Company recognized a provisional amount of $443.2 million, which decreased diluted net income per common share by $1.79 for the nine months ended December 31, 2017, and which was included as a component of income tax expense from continuing operations. The Company will continue to refine provisional balances and adjustments may be made under SAB 118 during the measurement period as a result of future changes in interpretation, information available, assumptions made by the Company and/or issuance of additional guidance and these adjustments could be material.

The one-time transition tax is based on the Company's total post-1986 earnings and profits ("E&P") of its foreign subsidiaries. Substantially all of the Company's E&P were permanently reinvested outside the U.S prior to the Act. The Company recorded provisional U.S. amounts for its one-time transition tax liabilities, resulting in an increase in income tax expense of $627.7 million. In addition, the Company released the deferred tax liabilities related to non-permanently reinvested E&P, resulting in a decrease in income tax expense of $5.5 million. The net increase to tax expense is $622.2 million. The one-time transition tax may be elected to be paid over a period of eight years. The Company intends to make this election.

The Company has not yet completed its calculation of the total post-1986 E&P for its foreign subsidiaries. In addition, the one-time transition tax is based in part on the amount of those earnings held in cash and other specified assets either as of the end of fiscal 2018 or the average of the year-end balances for fiscal 2016 and fiscal 2017. The Company's calculation of this amount will change with further analysis, fourth quarter activities, and further guidance from the U.S. federal and state tax authorities about the application of these new rules. The Company will continue to evaluate the impact of the tax law change as it relates to the accounting for the outside basis difference of its foreign entities.

As a result of the reduction of the corporate income tax rate to 21.0%, U.S. GAAP requires companies to remeasure their deferred tax assets and liabilities as of the date of enactment, with resulting tax effects accounted for in the reporting period of enactment. The Company remeasured deferred tax assets and liabilities based on the rates at which they are expected to to be utilized in the future. The provisional amount recorded for the remeasurement and resulting income tax benefit of the Company's deferred tax balance was $142.6 million. The Company's actual income tax benefit may vary materially from the provisional amount because the final analysis will be based on balances as of March 31, 2018.

Due to the Act, the Company released its valuation allowance on foreign tax credits during the three months ended December 31, 2017. The provisional amount recorded for the valuation allowance release was an income tax benefit of $36.4 million. The Company is still evaluating how the Act impacts the valuation allowance on state net operating loss carryforwards and state tax credits, and the Company may report an adjustment to the valuation allowances in accordance with SAB 118 in subsequent quarters.

The Company's effective tax rate for the three and nine months ended December 31, 2017 is higher compared to the prior year primarily due to the one-time transition tax net of the reversal of the related deferred tax liabilities. The Company's effective tax rate is different than statutory rates in the U.S. due primarily to the one-time transition tax net of the reversal of the related deferred tax liabilities, as well as its mix of earnings in foreign jurisdictions with lower tax rates as well as numerous tax holidays it receives related to its Thailand manufacturing operations based on its investment in property, plant and equipment in Thailand. The Company's tax holiday periods in Thailand expire at various times in the future, however, the Company actively seeks to obtain new tax holidays. The Company does not expect the future expiration of any of its tax holiday periods in Thailand to have a material impact on its effected tax rate. The material components of foreign income taxed at a rate lower than the U.S. are earnings accrued in Thailand and Ireland, and earnings accrued by the Company's offshore technology company which is resident in the Cayman Islands.

The Company files U.S. federal, U.S. state, and foreign income tax returns. For U.S. federal, and in general for U.S. state tax returns, the fiscal 2005 and later tax years remain effectively open for examination by tax authorities. For foreign tax returns, the Company is generally no longer subject to income tax examinations for years prior to fiscal 2007.

The Company recognizes liabilities for anticipated tax audit issues in the U.S. and other domestic and international tax jurisdictions based on its estimate of whether, and the extent to which, additional tax payments are more likely than not. The Company believes that it has appropriate support for the income tax positions taken and to be taken on its tax returns and that its accruals for tax liabilities are adequate for all open years based on an assessment of many factors including past experience and interpretations of tax laws applied to the facts of each matter.

The Company believes it maintains appropriate reserves to offset any potential income tax liabilities that may arise upon final resolution of matters for open tax years. If such reserve amounts ultimately prove to be unnecessary, the resulting reversal of such reserves would result in tax benefits being recorded in the period the reserves are no longer deemed necessary. If such amounts prove to be less than an ultimate assessment, a future charge to expense would be recorded in the period in which the assessment is determined. Although the timing of the resolution or closure of audits is highly uncertain, the Company does not believe it is reasonably possible that the unrecognized tax benefits would materially change in the next 12 months.