Acquisition of RSI Home Products, Inc. (the "RSI Acquisition") (Supplemental Pro Forma Financial Information) (Details) - RSI Home Products, Inc. $ / shares in Units, $ in Thousands	6 Months Ended
	Oct. 31, 2017 USD ($) $ / shares
Business Acquisition [Line Items]
Net Sales | $	$ 406,303
Net Income | $	$ 22,454
Net earnings per share - basic | $ / shares	$ 1.27
Net earnings per share - diluted | $ / shares	$ 1.27