Commitments and Contingencies - Additional Information (Details) $ in Thousands							3 Months Ended		12 Months Ended
	Dec. 14, 2015	Nov. 21, 2014 USD ($)	Nov. 13, 2014 USD ($) ft² Term	Jun. 04, 2014 USD ($)	Mar. 12, 2013 USD ($)	Jun. 12, 2012 USD ($)	Apr. 30, 2016 USD ($)	Jul. 31, 2013 USD ($)	Apr. 30, 2016 USD ($)	Apr. 30, 2015 USD ($)	Apr. 30, 2014 USD ($)
Operating Leased Assets [Line Items]
Office space | ft²			137,615
Lease commencement date	Dec. 14, 2015
Number of successive periods of five years terms | Term			2
Lease extension period			5 years
Operating leases, rent expense									$ 5,000	$ 4,100	$ 4,400
Operating leases, future minimum payments due, future minimum sublease rentals							$ 800		800
Revolving line of credit							42,000		42,000	57,000
Business combination, consideration transferred						$ 150,800
Cash consideration				$ 30,000						30,000
Amount that placed into escrow as partial security for the Company's indemnification obligations				$ 4,500
Discontinued operation, loss on disposal of discontinued operation, net of tax previously recognized								$ (9,192)		(10,729)
Loss on disposal of discontinued operations, net of tax									0	$ (1,537)	$ (9,192)
Loss contingency, damages sought, value					$ 91,400
Office space lease contract
Operating Leased Assets [Line Items]
Security deposit for the lease			$ 8,000
Revolving credit facility
Operating Leased Assets [Line Items]
Repayments of debt							15,000
Revolving line of credit							$ 42,000		$ 42,000
Credit facility | Revolving credit facility
Operating Leased Assets [Line Items]
Line of Credit Facility, maximum borrowing capacity		$ 70,000
Revolving letter of credit with a borrowing capacity		15,000
Line of Credit Facility, expiration date									Nov. 21, 2017
Swingline Loan | Credit facility | Revolving credit facility
Operating Leased Assets [Line Items]
Line of Credit Facility, maximum borrowing capacity		$ 3,000
Daily adjusting LIBOR rate | Credit facility | Revolving credit facility
Operating Leased Assets [Line Items]
Interest above daily adjusting LIBOR rate		3.50%