Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jul. 31, 2019	Apr. 30, 2019
Condensed Consolidated Balance Sheets
Trade accounts and notes receivable, allowances (in dollars)	$ 6,683	$ 6,432
Property and equipment, accumulated depreciation (in dollars)	$ 132,815	$ 123,583
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	500,000	500,000
Common stock, shares issued	41,589	40,375
Common stock, shares outstanding	41,589	40,375
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000	50,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0