Treasury Stock and Repurchase Program (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended			12 Months Ended
	Jan. 31, 2013	Oct. 31, 2012	Jan. 31, 2013		Jan. 31, 2012	Apr. 30, 2012
Treasury Stock At Cost [Roll Forward]
Balance (in shares)			103,619	[1],[2]
Purchases effected in open market, shares	12,890	3,440
Balance (in shares)	119,949		119,949			103,619	[1],[2]
Total Average Cost, Beginning Balance (in dollars)			$ 1,390	[1],[2]
Purchases effected in open market (in dollars)	117	30	147		946
Total Average Cost, Ending Balance (in dollars)	1,537		1,537			1,390	[1],[2]
Average cost per share	$ 9.11	$ 8.84	$ 12.81			$ 13.41	[1],[2]
Aggregate purchase price remaining under the program	$ 2,853	$ 2,970

[1] Includes the balance of 18,400 shares with a total average cost of $354,000 that were acquired prior to the repurchase program authorized in January 2011.

[2] Includes the balance of 85,219 shares with a total average cost of $1,036,000 that were acquired during the former repurchase program, which was authorized in January 2011 and expired in January 2012.