Income taxes (Notes)

6 Months Ended

Sep. 30, 2014

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 8.0% for the six-month period ended September 30, 2014 and 11.5% for the six-month period ended September 30, 2013.  The Company's effective tax rate for six-month period ended September 30, 2014 is lower compared to the prior year primarily due to closure of statute of limitations, certain audit settlements with taxing authorities and a change in judgment regarding certain state valuation allowances. During the three-month period ended September 30, 2014, approximately $6.8 million of prior year tax positions were released which increased each of the basic and diluted net income per common share for the three-month period ended September 30, 2014 by approximately $0.03. During the six-month period ended September 30, 2014, approximately $7.4 million of prior year tax positions were released which increased the basic and diluted net income per common share for the six-month period ended September 30, 2014 by approximately $0.04 and $0.03, respectively. The Company's effective tax rate is lower than statutory rates in the U.S. due primarily to its mix of earnings in foreign jurisdictions with lower tax rates.

At September 30, 2014, the Company had $212.1 million of unrecognized tax benefits.  Unrecognized tax benefits increased by $32.1 million compared to March 31, 2014 primarily as a result of unrecognized tax benefits from the Company's acquisitions of Supertex and ISSC, the ongoing accrual for uncertain tax positions and the accrual of deficiency interest on these positions. The majority of the increase in the uncertain tax position does not result in a change in the Company's effective tax rate. The Company evaluated the impact of the adoption of ASU 2013-11 on its condensed consolidated financial statements and determined that $72.7 million of unrecognized tax benefits can be presented as a reduction to deferred tax assets for net operating loss carryforward and other tax credit carryforwards. There was no income statement impact as a result of adopting this accounting standard.

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 2011 and later tax years remain open for examination by tax authorities.  The U.S. Internal Revenue Service (IRS) is currently auditing Microchip's and Standard Microsystems Corporation's (SMSC) 2011 and 2012 tax years.  The IRS is also currently auditing Supertex's 2013 tax year. For foreign tax returns, the Company is generally no longer subject to income tax examinations for years prior to fiscal 2006.

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 and/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.