Income Taxes Foreign and U.S. Federal and State Tax Carryforwards for Income Tax Purposes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015
Operating Loss and Tax Credit Carry Forward
Foreign net operating loss carryforwards	35,650
Internal Revenue Service (IRS)
Operating Loss and Tax Credit Carry Forward
Research and experimentation credit carryforward	79,817
Net operating loss carryforward	112,807
Foreign tax credits	17,167
Alternative minimum tax credits	2,682
Miscellaneous	1,601
Internal Revenue Service (IRS) | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of operating loss carryforwards	Jan. 31, 2020
Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of operating loss carryforwards	Jan. 31, 2035
State and Local Jurisdiction
Operating Loss and Tax Credit Carry Forward
Research and experimentation credit carryforward	18,979
Net operating loss carryforward	214,660
Miscellaneous	932
State and Local Jurisdiction | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of operating loss carryforwards	Jan. 31, 2016
State and Local Jurisdiction | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of operating loss carryforwards	Jan. 31, 2035
Research Tax Credit Carryforward [Member] | Internal Revenue Service (IRS) | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2019
Research Tax Credit Carryforward [Member] | Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2035
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2016
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2030
Foreign Tax Credits [Member] | Internal Revenue Service (IRS) | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2016
Foreign Tax Credits [Member] | Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2025
Childcare Tax Credit [Member] | Internal Revenue Service (IRS) | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2023
Childcare Tax Credit [Member] | Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2035