Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended	12 Months Ended
	Jan. 31, 2017 USD ($)	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($) partner	Jan. 31, 2015 USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Net foreign currency transaction gains (losses)		$ (2,600,000)	$ (2,300,000)	$ (648,000)
Restricted cash	$ 12,734,000	12,734,000	7,132,000
Acquisition of intangible assets		1,000,000	0	9,125,000
Impairment charges		0	0	0
Deferred commissions, current	15,787,000	15,787,000	15,703,000
Deferred income taxes, non-current	14,900,000	14,900,000	14,300,000
Sales commission expenses		$ 84,800,000	47,200,000	27,700,000
Period required with included controller refresh to have additional maintenance and support renewal		3 years
Additional maintenance and support period		3 years
Warranty reserve	0	$ 0
Capitalization of software development cost	0	0	0	0
Advertising expenses		$ 10,700,000	$ 6,200,000	1,400,000
New accounting pronouncement early adoption effect
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Decrease in non-current deferred tax assets	5,500,000
Decrease in current deferred tax liability	5,800,000
Increase in non-current deferred tax liability	$ 300,000
Hardware
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period		3 years
Embedded software
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period		90 days
Technology patents
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Acquisition of intangible assets		$ 1,000,000		$ 9,100,000
Estimated useful life of intangible assets		5 years		7 years
Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Contractual term		1 year
Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Contractual term		5 years
Test equipment
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		2 years
Computer equipment and software | Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		2 years
Computer equipment and software | Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		3 years
Furniture and fixtures
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		7 years
Accounts receivable | Customer concentration risk
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of major channel partner or customer | partner			2
Concentration risk percentage		10.00%	11.00%
Sales revenue net | Customer concentration risk
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		11.00%