Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	12 Months Ended			97 Months Ended
	Dec. 31, 2014 USD ($) $ / shares shares	Mar. 31, 2016 USD ($) Customer Segment	Mar. 31, 2015 USD ($) Customer	Mar. 31, 2014 USD ($) Customer	Mar. 31, 2016 USD ($)	Apr. 30, 2014 $ / shares shares
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Company incorporation date		Feb. 20, 2008
Entity Incorporation, State Name		Delaware
Proceeds from sale of common stock, net of underwriters' discounts and commissions			$ 119,924,000
Number of reportable segments | Segment		1
Cash and cash equivalents, original maturity term		Three months or less
Other-than-temporarily impaired investments		$ 0	0
Gross value of capitalized internal use software		7,700,000	10,000,000	$ 5,500,000	$ 7,700,000
Stock-based compensation costs		1,000,000	1,000,000	300,000
Amortization expense		6,700,000	3,900,000	2,100,000
Net book value of capitalized software		12,600,000	12,600,000		12,600,000
Impairment of long-lived assets		$ 0	0	$ 0
Goodwill impairment					0
Current deferred tax liabilities			$ 913,000
Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Revenue recognition, contract term		1 month
Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Revenue recognition, contract term		12 months
Computers and software [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life		3 years
Other Office Equipment and Site-related Computer Hardware [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life		3 years
Furniture and Fixtures [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life		5 years
Leasehold Improvements [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, estimated useful life		The shorter of the lease-term or the estimated useful life of the related asset.
Capitalized Software Development Costs [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life		3 years
Common Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of common stock shares issued upon conversion of convertible preferred stock | shares	24,885,778
Accounts Receivable [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer		0	1
Revenue [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer		0	0	0
Series F Convertible Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued, price per share | $ / shares						$ 28.93
Convertible preferred stock conversion rate | shares	1.02					1
Series A Through E Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Convertible preferred stock conversion rate | shares	1
Convertible Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of convertible preferred stock shares converted | shares	24,813,343
Credit Concentration Risk [Member] | Accounts Receivable [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration of risk, percentage		10.00%	12.00%
Credit Concentration Risk [Member] | Revenue [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration of risk, percentage		10.00%	10.00%	10.00%
Initial Public Offering [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares	5,750,000
Proceeds from sale of common stock, net of underwriters' discounts and commissions	$ 123,000,000
Common stock shares issued, price per share | $ / shares	$ 23.00					$ 23.00
Offering expenses	$ 3,100,000
Initial Public Offering [Member] | Series F Convertible Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Convertible preferred stock conversion rate | shares						11.02
Sales and Marketing [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Advertising Expense		$ 25,500,000	$ 25,100,000	$ 22,400,000
Restatement Adjustment [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Current deferred tax liabilities		(900,000)			(900,000)
Non-current deferred tax liabilities		$ 900,000			$ 900,000