Discontinued Operations - Results from Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Revenues from discontinued operations	$ 0	$ 0	$ 0	$ 2,535
Income from discontinued operations before income taxes	0	0	0	303
Income tax expense	0	0	0	23
Net income from discontinued operations	0	0	0	280
Loss on disposal of discontinued operations, net of tax	0	0	0	(1,537)
Loss from discontinued operations, net of tax	$ 0	$ 0	$ 0	$ (1,257)