Basis of Presentation, Business and Summary of Significant Accounting Policies - Derivative Instruments (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 31, 2014	Apr. 30, 2015	Jan. 31, 2015	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Derivative [Line Items]
Purchase price						$ 4,638
Increase (decrease) in fair value of financial instrument, net of tax				$ 264	$ (1,158)	$ 10
Interest rate cap
Derivative [Line Items]
Strike rate (as a percent)				2.00%
Capped interest rate (as a percent)				5.75%
Purchase price	$ 4,638
Decrease in fair value of derivative instrument from purchase date to date of hedge designation			$ 2,494
Increase (decrease) in fair value of financial instrument, net of tax		$ 10		$ 264	(1,158)
Designated | Interest rate cap
Derivative [Line Items]
Notional amount				275,000
Designated | Interest rate cap | Other assets
Derivative [Line Items]
Derivative asset				$ 88	$ 271