Loss Per Share (Details) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Shares excluded from the calculation of diluted loss per share	1,311	1,058
Non-vested restricted Class B common stock [Member]
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Shares excluded from the calculation of diluted loss per share	1,279	1,058
Stock options [Member]
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Shares excluded from the calculation of diluted loss per share	32