Income Taxes - Additional Information (Details) - USD ($)		12 Months Ended
	Jan. 01, 2018	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Operating Loss Carryforwards [Line Items]
Tax Cuts and Jobs Act of 2017, decrease in deferred tax assets	$ 98,000,000
Deferred tax assets, increase (decrease) in valuation allowance		$ (31,300,000)	$ 90,900,000	$ 68,000,000
Gross unrecognized tax benefit		12,401,000	$ 6,375,000	$ 15,470,000	$ 13,874,000
Current or cumulative interest and penalties related to uncertain tax positions		$ 0
Federal
Operating Loss Carryforwards [Line Items]
Blended tax rate		32.90%
Net operating loss carryforwards		$ 508,900,000
Research and development tax credit carryforwards		26,600,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		331,900,000
Research and development tax credit carryforwards		22,200,000
Non-U.S.
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries		$ 20,800,000