Share Repurchase Program (Details) - USD ($)		1 Months Ended		3 Months Ended		7 Months Ended
	Feb. 12, 2015	Apr. 30, 2018	Apr. 30, 2017	Mar. 31, 2018	Mar. 31, 2017	Jul. 31, 2018	May 04, 2017
Equity, Class of Treasury Stock [Line Items]
Authorized amount for repurchase	$ 20,000,000						$ 30,000,000
Repurchase program period	2 years
Stock Repurchased During Period, Shares				931,749	569,624
Stock Repurchased During Period, Value				$ (8,671,000)	$ (5,500,000)
Treasury Stock Acquired, Average Cost Per Share				$ 9.31	$ 9.64
Payments for Repurchase of Common Stock				$ 8,048,000	$ 4,342,000
Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Payments for Repurchase of Common Stock			$ 1,200,000	$ 7,900,000	$ 4,300,000
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased During Period, Shares						1,735,983
Stock Repurchased During Period, Value						$ (17,000,000)
Treasury Stock Acquired, Average Cost Per Share						$ 9.75
Subsequent Event | Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Payments for Repurchase of Common Stock		$ 700,000