XML 37 R32.htm IDEA: XBRL DOCUMENT v3.2.0.727
Organization and Summary of Significant Accounting Policies - Levels of fair value measurements of investments (Details) - USD ($)
$ in Thousands
Jul. 31, 2015
Apr. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents $ 5,605 $ 5,272
Securities available-for-sale 9,627 9,632
Investments, fair value disclosure 15,232 14,904
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 5,605 5,272
Securities available-for-sale 9,627 9,632
Investments, fair value disclosure $ 15,232 $ 14,904
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents    
Securities available-for-sale    
Investments, fair value disclosure    
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents    
Securities available-for-sale    
Investments, fair value disclosure