Stock-Based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands						1 Months Ended	12 Months Ended
	Sep. 12, 2019	Jun. 30, 2019	Jun. 19, 2019	Dec. 13, 2018	Dec. 14, 2017	Jun. 30, 2019	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Stock-Based Compensation (Textual)
Fair value of options on grant date							$ 4.41
Options exercise price							$ 14.15
Option granted to purchase common stock
Option term, description							Option awards generally vest on a graded basis over three years of service and have ten-year contractual terms.
Fair value of straight line basis, description							The Company estimated that the fair value of the options on the date of grant was $3.3 million, which is being recognized on a straight-line basis over the requisite three-year service period ending in May 2020.
Common Class B [Member]
Stock-Based Compensation (Textual)
Additional shares available stock option incentive plan for grants				100,000	300,000
Shares of common stock reserved for award under 2015 stock option and incentive plan							1,100
Shares of common stock available for future grants							300
Deferred Stock Units [Member]
Stock-Based Compensation (Textual)
Non-vested stock options, weighted-average period							10 months 25 days
Fair value of options on grant date							$ 10.35
Total unrecognized non-vested stock-based compensation							$ 3,600
Fair value options date of grant							$ 4,300
Deferred Stock Units [Member] | Common Class B [Member]
Stock-Based Compensation (Textual)
Vesting date, description		The DSUs will vest in three equal amounts on each of January 6, 2020, January 5, 2021, and January 5, 2022. The number of shares that will be issuable on each vesting date will vary between 50% to 200% of the number of DSUs that vest on that vesting date, depending on the market price for the underlying Class B common stock on the vesting date relative to the market price at the time of the grant. In addition, the grantee will have the right to elect a later vesting date no later than November 29, 2019 for the January 6, 2020 vesting date, and no later than November 30, 2020 for the January 5, 2021 vesting date. A grantee will have the option to elect a later vesting date for one-half or all of the shares scheduled to vest on the then upcoming vesting date.
Company granted deferred stock units equity incentive program						410,900
Restricted Stock [Member]
Stock-Based Compensation (Textual)
Non-vested stock options, weighted-average period							1 year 2 months 12 days
Total unrecognized non-vested stock-based compensation							$ 800
Total grant date fair value of shares vested							700	$ 3,400	$ 4,100
Restricted Stock [Member] | Common Class B [Member]
Stock-Based Compensation (Textual)
Equity grant of restricted shares			20,000
Vesting date, description			The Company's Executive Vice President of Strategy and Legal Affairs, which vest in full on January 5, 2022 only if the closing price of the Company's Class B common stock on the preceding trading day is $13.00 or above. The minimum price of $13.00 per share shall be adjusted by the Compensation Committee if there is a spin-off or significant stock buybacks prior to January 5, 2022.
Restricted Stock [Member] | Common Class B [Member] | Shmuel Jonas [Member]
Stock-Based Compensation (Textual)
Equity grant of restricted shares			170,000
Stock Options [Member]
Stock-Based Compensation (Textual)
Total intrinsic value of options exercised during the period									$ 400
Total unrecognized compensation cost							$ 800
Non-vested stock options, weighted-average period							6 months
Stock Options [Member] | Common Class B [Member]
Stock-Based Compensation (Textual)
Additional shares available stock option incentive plan for grants	400,000
Options expire date					May 01, 2022
Options exercise price					$ 14.93
Option granted to purchase common stock					1,000
Repurchase right number of shares option on May 2, 2020					333,334
Fair value options date of grant					$ 3,300