Share Repurchase (Details) - USD ($)	3 Months Ended	6 Months Ended
	Oct. 27, 2018	Oct. 27, 2018	Apr. 30, 2018	Sep. 30, 2015
Share Repurchase
Stock Repurchase Program, Authorized Amount				$ 25,000,000
Shares repurchased and retired	0	0
Share authorized for future repurchases	$ 21,200,000	$ 21,200,000	$ 21,200,000