Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Income Tax [Line Items]
U.S. federal statutory tax rate	34.00%	34.00%	34.00%
Valuation allowance increased	$ 13,100,000	$ 14,600,000	$ 10,100,000
Unrecognized tax benefit would affect company's effective tax rate if recognized	122,000
Unrecognized tax benefits	$ 5,441,000	$ 3,304,000	$ 2,846,000
Income tax examination, description	As a result of net operating loss carryforwards, the Company is subject to audits for tax years 2006 and forward for federal purposes and 2009 and forward for California purposes.
California
Income Tax [Line Items]
Operating loss carryforwards expiration year	2029
California | Research and Development
Income Tax [Line Items]
Tax credit carryforwards amount	$ 3,600,000
Federal
Income Tax [Line Items]
Net operating loss carryforwards	$ 151,100,000
Operating loss carryforwards expiration year	2026
Excess tax benefit from stock option exercises included in net operating loss carryforwards	$ 19,300,000
Tax credit carryforwards expiration year	2031
Reduction in operating loss carryforwards	$ 3,500,000
Federal | Research and Development
Income Tax [Line Items]
Tax credit carryforwards amount	3,500,000
State
Income Tax [Line Items]
Net operating loss carryforwards	86,100,000
Excess tax benefit from stock option exercises included in net operating loss carryforwards	11,600,000
Reduction in operating loss carryforwards	3,500,000
Foreign
Income Tax [Line Items]
Tax credit carryforwards amount	$ 660,000
Tax credit carryforwards expiration year	2025