Discontinued Operations - Results from Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Revenues from discontinued operations	$ 0	$ 0	$ 2,535
Income from discontinued operations before income taxes	0	0	303
Income tax expense	0	0	23
Net income from discontinued operations	0	0	280
Loss on disposal of discontinued operations, net of tax	0	0	1,537
Loss from discontinued operations, net of tax	$ 0	$ 0	$ (1,257)