Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Income Tax [Line Items]
Deferred tax assets, increase in valuation allowance	$ 90,900,000	$ 68,000,000	$ 66,600,000
Gross unrecognized tax benefit	6,375,000	$ 15,470,000	$ 13,874,000	$ 4,676,000
Current or cumulative interest and penalties related to uncertain tax positions	0
Federal
Income Tax [Line Items]
Net operating loss carryforwards	464,200,000
Research and development tax credit carryforwards	12,100,000
State
Income Tax [Line Items]
Net operating loss carryforwards	323,800,000
Research and development tax credit carryforwards	12,600,000
Non-U.S.
Income Tax [Line Items]
Undistributed earnings of foreign subsidiaries	$ 11,100,000