Federal, State and Local Income Taxes - Provision for income taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Jul. 31, 2014	Jul. 31, 2013
Current tax expense:
Federal	$ 869	$ 216
State and local	90	28
Current tax expense	959	244
Deferred tax expense:
Federal	106	506
State and local	24	81
Deferred tax expense	130	587
Income tax provision:	$ 1,089	$ 831

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.