Consolidated Statements of Changes in Shareholders' Equity Unaudited (USD $)
 9 Months Ended 12 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended 12 Months Ended
Apr. 30, 2013
Common Stock [Member]
Class A [Member]
Jul. 31, 2012
Common Stock [Member]
Class A [Member]
Jul. 31, 2011
Common Stock [Member]
Class A [Member]
Apr. 30, 2013
Common Stock [Member]
Class B [Member]
Jul. 31, 2012
Common Stock [Member]
Class B [Member]
Jul. 31, 2011
Common Stock [Member]
Class B [Member]
Apr. 30, 2013
Capital in Excess of Par Value [Member]
Jul. 31, 2012
Capital in Excess of Par Value [Member]
Apr. 30, 2013
Retained earnings [Member]
Jul. 31, 2012
Retained earnings [Member]
Apr. 30, 2013
Accumulated Other Comprehensive Income (loss) [Member]
Jul. 31, 2012
Accumulated Other Comprehensive Income (loss) [Member]
Apr. 30, 2013
Treasury Stock [Member]
Jul. 31, 2012
Treasury Stock [Member]
Apr. 30, 2013
Noncontrolling Interest [Member]
Jul. 31, 2012
Noncontrolling Interest [Member]
Balance $ 26,851 $ 26,851 $ 26,851 $ 17,087 $ 17,087 $ 17,087 $ 19,751,992 $ 19,983,029 $ 29,534,783 $ 30,797,763 $ 711,842 $ 1,527,189 $ (1,897,032) $ (2,317,515) $ 4,612,018 $ 3,923,429
Balance (in shares) 2,685,151 2,685,151 2,685,151 1,708,574 1,708,574 1,708,574             149,531 190,724    
Net income             0 0 1,713,019 773,579 0 0     654,544 2,266,171
Foreign currency translation adjustments             0 0 0 0 123,895 (871,476)     (12,648) 124,455
Cash dividends paid             0 0 (1,018,540) (2,036,559) 0 0     0 0
Unrealized investment gain, net             0 0 0 0 364 17,597     0 0
Repurchase of Class A common stock               0   0   0   (363,050)   0
Repurchase of Class A common stock (in shares)                           22,825    
Issuance of stock under stock award plan               (716,662)   0   0   716,662   0
Issuance of stock under stock award plan (in shares)                           (62,099)    
Share-based compensation expense             379,803 731,583 0 0 0 0     0 0
Tax impact of share based compensation               105,988   0   0       0
Sale of subsidiary shares to noncontrolling interests               0   0   0       41,634
Distributions to noncontrolling interests             0 0 0 0 0 0     (1,338,842) (1,123,896)
Purchase of additional noncontrolling interests             (168,486) (351,946) 0 0 0 38,532 98,799 66,871 (775,935) (619,775)
Purchase of additional noncontrolling interests (in shares)                         (7,804) (5,208)    
Stock award plan forfeitures             0 0 0 0 0 0 0   0 0
Stock award plan forfeitures (in shares)                         798 3,289    
Balance $ 26,851 $ 26,851 $ 26,851 $ 17,087 $ 17,087 $ 17,087 $ 19,963,309 $ 19,751,992 $ 30,229,262 $ 29,534,783 $ 836,101 $ 711,842 $ (1,798,233) $ (1,897,032) $ 3,139,137 $ 4,612,018
Balance (in shares) 2,685,151 2,685,151 2,685,151 1,708,574 1,708,574 1,708,574             142,525 149,531