Income Taxes Foreign and U.S. Federal and State Tax Carryforwards for Income Tax Purposes (Details) $ in Thousands	12 Months Ended
	Jan. 31, 2016 USD ($)
Operating Loss and Tax Credit Carry Forward
Foreign net operating loss carryforwards	$ 20,093
Internal Revenue Service (IRS)
Operating Loss and Tax Credit Carry Forward
Research and experimentation credit carryforward	88,987
Net operating loss carryforward	120,030
Foreign tax credits	19,433
Alternative minimum tax credits	2,682
Miscellaneous	$ 1,843
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, 2036
State and Local Jurisdiction
Operating Loss and Tax Credit Carry Forward
Research and experimentation credit carryforward	$ 21,842
Net operating loss carryforward	202,389
Miscellaneous	$ 1,038
State and Local Jurisdiction | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of operating loss carryforwards	Jan. 31, 2017
State and Local Jurisdiction | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of operating loss carryforwards	Jan. 31, 2036
Research Tax Credit Carryforward | 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 | Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2036
Research Tax Credit Carryforward | State and Local Jurisdiction | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2017
Research Tax Credit Carryforward | State and Local Jurisdiction | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2031
Foreign Tax Credits | Internal Revenue Service (IRS) | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2017
Foreign Tax Credits | Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2026
Childcare Tax Credit | Internal Revenue Service (IRS) | Minimum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2023
Childcare Tax Credit | Internal Revenue Service (IRS) | Maximum
Operating Loss and Tax Credit Carry Forward
Expiration date of tax credit carryforwards	Jan. 31, 2036