12. Income Taxes

The following table provides details of income taxes for the periods indicated:

	Three Months Ended						Nine Months Ended
	October 31,						October 31,
	2015			2014			2015			2014
	(in thousands)
Income before income taxes	$	30,496		$	18,691		$	75,896		$	34,870
Provision for income taxes		1,035			364			4,484			1,973
Effective tax rate		3.4	%		2.0	%		5.9	%		5.7	%

The Company files federal and state income tax returns in the United States and in various foreign jurisdictions. The tax years 2013 to 2015 remain open to examination by U.S. federal tax authorities. The tax years 2004 to 2015 remain open to examination by U.S. state tax authorities. The tax years 2010 to 2015 remain open to examination by material foreign tax authorities.

The Company is subject to ongoing tax examinations of its tax returns by the Internal Revenue Service and other tax authorities in various jurisdictions. The Company regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of its provision for income taxes. These assessments can require considerable estimates and judgments. As of October 31, 2015, the gross amount of unrecognized tax benefits was approximately $24.1 million. If the estimates of income tax liabilities prove to be less than the ultimate assessment, then a further charge to expense could be required. If events occur and the payment of these amounts ultimately proves to be unnecessary, the reversal of the liabilities could result in tax benefits being recognized in the period in which the Company determines the liabilities are no longer necessary. The Company does not anticipate changes to its uncertain tax positions during the next twelve months.

On July 27, 2015, in Altera Corp. v. Commissioner , the U.S. Tax Court issued an opinion related to the treatment of stock-based compensation expense in an intercompany cost-sharing agreement. The decision was finalized by the U.S. Tax Court on December 1, 2015 and the IRS has a 90-day period to appeal. To date, the U.S. Department of the Treasury has not withdrawn the requirement to include stock-based compensation in intercompany cost-sharing arrangements from its regulations. Due to the uncertainty related to the status of the current regulations and whether the Internal Revenue Service will appeal the decision, the Company has not recognized tax benefits as of October 31, 2015 in its Condensed Consolidated Statements of Operations. The Company will continue to monitor ongoing developments and potential impacts to its condensed consolidated financial statements.